init

java/org/apache/tomcat/util/modeler/AttributeInfo.java

@@ -0,0 +1,164 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.tomcat.util.modeler;
+
+import javax.management.MBeanAttributeInfo;
+
+
+/**
+ * <p>Internal configuration information for an <code>Attribute</code>
+ * descriptor.</p>
+ *
+ * @author Craig R. McClanahan
+ */
+public class AttributeInfo extends FeatureInfo {
+    static final long serialVersionUID = -2511626862303972143L;
+
+    // ----------------------------------------------------- Instance Variables
+    protected String displayName = null;
+
+    // Information about the method to use
+    protected String getMethod = null;
+    protected String setMethod = null;
+    protected boolean readable = true;
+    protected boolean writeable = true;
+    protected boolean is = false;
+
+    // ------------------------------------------------------------- Properties
+
+    /**
+     * @return the display name of this attribute.
+     */
+    public String getDisplayName() {
+        return this.displayName;
+    }
+
+    public void setDisplayName(String displayName) {
+        this.displayName = displayName;
+    }
+
+    /**
+     * @return the name of the property getter method, if non-standard.
+     */
+    public String getGetMethod() {
+        if(getMethod == null)
+            getMethod = getMethodName(getName(), true, isIs());
+        return this.getMethod;
+    }
+
+    public void setGetMethod(String getMethod) {
+        this.getMethod = getMethod;
+    }
+
+    /**
+     * Is this a boolean attribute with an "is" getter?
+     * @return <code>true</code> if this is a boolean attribute
+     *  with an "is" getter
+     */
+    public boolean isIs() {
+        return this.is;
+    }
+
+    public void setIs(boolean is) {
+        this.is = is;
+    }
+
+
+    /**
+     * Is this attribute readable by management applications?
+     * @return <code>true</code> if readable
+     */
+    public boolean isReadable() {
+        return this.readable;
+    }
+
+    public void setReadable(boolean readable) {
+        this.readable = readable;
+    }
+
+
+    /**
+     * @return the name of the property setter method, if non-standard.
+     */
+    public String getSetMethod() {
+        if( setMethod == null )
+            setMethod = getMethodName(getName(), false, false);
+        return this.setMethod;
+    }
+
+    public void setSetMethod(String setMethod) {
+        this.setMethod = setMethod;
+    }
+
+    /**
+     * Is this attribute writable by management applications?
+     * @return <code>true</code> if writable
+     */
+    public boolean isWriteable() {
+        return this.writeable;
+    }
+
+    public void setWriteable(boolean writeable) {
+        this.writeable = writeable;
+    }
+
+    // --------------------------------------------------------- Public Methods
+
+
+    /**
+     * Create and return a <code>ModelMBeanAttributeInfo</code> object that
+     * corresponds to the attribute described by this instance.
+     * @return the attribute info
+     */
+    MBeanAttributeInfo createAttributeInfo() {
+        // Return our cached information (if any)
+        if (info == null) {
+            info = new MBeanAttributeInfo(getName(), getType(), getDescription(),
+                            isReadable(), isWriteable(), false);
+        }
+        return (MBeanAttributeInfo)info;
+    }
+
+    // -------------------------------------------------------- Private Methods
+
+
+    /**
+     * Create and return the name of a default property getter or setter
+     * method, according to the specified values.
+     *
+     * @param name Name of the property itself
+     * @param getter Do we want a get method (versus a set method)?
+     * @param is If returning a getter, do we want the "is" form?
+     * @return the method name
+     */
+    private String getMethodName(String name, boolean getter, boolean is) {
+        StringBuilder sb = new StringBuilder();
+        if (getter) {
+            if (is)
+                sb.append("is");
+            else
+                sb.append("get");
+        } else
+            sb.append("set");
+        sb.append(Character.toUpperCase(name.charAt(0)));
+        sb.append(name.substring(1));
+        return sb.toString();
+    }
+
+
+}

java/org/apache/tomcat/util/modeler/BaseAttributeFilter.java

@@ -0,0 +1,160 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+package org.apache.tomcat.util.modeler;
+
+
+import java.util.HashSet;
+
+import javax.management.AttributeChangeNotification;
+import javax.management.Notification;
+import javax.management.NotificationFilter;
+
+
+/**
+ * <p>Implementation of <code>NotificationFilter</code> for attribute change
+ * notifications.  This class is used by <code>BaseModelMBean</code> to
+ * construct attribute change notification event filters when a filter is not
+ * supplied by the application.</p>
+ *
+ * @author Craig R. McClanahan
+ */
+public class BaseAttributeFilter implements NotificationFilter {
+
+    private static final long serialVersionUID = 1L;
+
+    // ----------------------------------------------------------- Constructors
+
+    /**
+     * Construct a new filter that accepts only the specified attribute
+     * name.
+     *
+     * @param name Name of the attribute to be accepted by this filter, or
+     *  <code>null</code> to accept all attribute names
+     */
+    public BaseAttributeFilter(String name) {
+
+        super();
+        if (name != null)
+            addAttribute(name);
+
+    }
+
+
+    // ----------------------------------------------------- Instance Variables
+
+
+    /**
+     * The set of attribute names that are accepted by this filter.  If this
+     * list is empty, all attribute names are accepted.
+     */
+    private HashSet<String> names = new HashSet<>();
+
+
+    // --------------------------------------------------------- Public Methods
+
+
+    /**
+     * Add a new attribute name to the set of names accepted by this filter.
+     *
+     * @param name Name of the attribute to be accepted
+     */
+    public void addAttribute(String name) {
+
+        synchronized (names) {
+            names.add(name);
+        }
+
+    }
+
+
+    /**
+     * Clear all accepted names from this filter, so that it will accept
+     * all attribute names.
+     */
+    public void clear() {
+
+        synchronized (names) {
+            names.clear();
+        }
+
+    }
+
+
+    /**
+     * Return the set of names that are accepted by this filter.  If this
+     * filter accepts all attribute names, a zero length array will be
+     * returned.
+     * @return the array of names
+     */
+    public String[] getNames() {
+
+        synchronized (names) {
+            return names.toArray(new String[names.size()]);
+        }
+
+    }
+
+
+    /**
+     * <p>Test whether notification enabled for this event.
+     * Return true if:</p>
+     * <ul>
+     * <li>This is an attribute change notification</li>
+     * <li>Either the set of accepted names is empty (implying that all
+     *     attribute names are of interest) or the set of accepted names
+     *     includes the name of the attribute in this notification</li>
+     * </ul>
+     */
+    @Override
+    public boolean isNotificationEnabled(Notification notification) {
+
+        if (notification == null)
+            return false;
+        if (!(notification instanceof AttributeChangeNotification))
+            return false;
+        AttributeChangeNotification acn =
+            (AttributeChangeNotification) notification;
+        if (!AttributeChangeNotification.ATTRIBUTE_CHANGE.equals(acn.getType()))
+            return false;
+        synchronized (names) {
+            if (names.size() < 1)
+                return true;
+            else
+                return names.contains(acn.getAttributeName());
+        }
+
+    }
+
+
+    /**
+     * Remove an attribute name from the set of names accepted by this
+     * filter.
+     *
+     * @param name Name of the attribute to be removed
+     */
+    public void removeAttribute(String name) {
+
+        synchronized (names) {
+            names.remove(name);
+        }
+
+    }
+
+
+}

java/org/apache/tomcat/util/modeler/BaseNotificationBroadcaster.java

@@ -0,0 +1,192 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+package org.apache.tomcat.util.modeler;
+
+
+import java.util.ArrayList;
+import java.util.Iterator;
+
+import javax.management.ListenerNotFoundException;
+import javax.management.MBeanNotificationInfo;
+import javax.management.Notification;
+import javax.management.NotificationBroadcaster;
+import javax.management.NotificationFilter;
+import javax.management.NotificationListener;
+
+
+/**
+ * <p>Implementation of <code>NotificationBroadcaster</code> for attribute
+ * change notifications.  This class is used by <code>BaseModelMBean</code> to
+ * handle notifications of attribute change events to interested listeners.
+ *</p>
+ *
+ * @author Craig R. McClanahan
+ * @author Costin Manolache
+ */
+
+public class BaseNotificationBroadcaster implements NotificationBroadcaster {
+
+
+    // ----------------------------------------------------------- Constructors
+
+
+    // ----------------------------------------------------- Instance Variables
+
+
+    /**
+     * The set of registered <code>BaseNotificationBroadcasterEntry</code>
+     * entries.
+     */
+    protected ArrayList<BaseNotificationBroadcasterEntry> entries =
+            new ArrayList<>();
+
+
+    // --------------------------------------------------------- Public Methods
+
+
+    /**
+     * Add a notification event listener to this MBean.
+     *
+     * @param listener Listener that will receive event notifications
+     * @param filter Filter object used to filter event notifications
+     *  actually delivered, or <code>null</code> for no filtering
+     * @param handback Handback object to be sent along with event
+     *  notifications
+     *
+     * @exception IllegalArgumentException if the listener parameter is null
+     */
+    @Override
+    public void addNotificationListener(NotificationListener listener,
+                                        NotificationFilter filter,
+                                        Object handback)
+        throws IllegalArgumentException {
+
+        synchronized (entries) {
+
+            // Optimization to coalesce attribute name filters
+            if (filter instanceof BaseAttributeFilter) {
+                BaseAttributeFilter newFilter = (BaseAttributeFilter) filter;
+                for (BaseNotificationBroadcasterEntry item : entries) {
+                    if ((item.listener == listener) &&
+                        (item.filter != null) &&
+                        (item.filter instanceof BaseAttributeFilter) &&
+                        (item.handback == handback)) {
+                        BaseAttributeFilter oldFilter =
+                            (BaseAttributeFilter) item.filter;
+                        String newNames[] = newFilter.getNames();
+                        String oldNames[] = oldFilter.getNames();
+                        if (newNames.length == 0) {
+                            oldFilter.clear();
+                        } else {
+                            if (oldNames.length != 0) {
+                                for (int i = 0; i < newNames.length; i++)
+                                    oldFilter.addAttribute(newNames[i]);
+                            }
+                        }
+                        return;
+                    }
+                }
+            }
+
+            // General purpose addition of a new entry
+            entries.add(new BaseNotificationBroadcasterEntry
+                        (listener, filter, handback));
+        }
+
+    }
+
+
+    /**
+     * Return an <code>MBeanNotificationInfo</code> object describing the
+     * notifications sent by this MBean.
+     */
+    @Override
+    public MBeanNotificationInfo[] getNotificationInfo() {
+        return new MBeanNotificationInfo[0];
+    }
+
+
+    /**
+     * Remove a notification event listener from this MBean.
+     *
+     * @param listener The listener to be removed (any and all registrations
+     *  for this listener will be eliminated)
+     *
+     * @exception ListenerNotFoundException if this listener is not
+     *  registered in the MBean
+     */
+    @Override
+    public void removeNotificationListener(NotificationListener listener)
+        throws ListenerNotFoundException {
+
+        synchronized (entries) {
+            Iterator<BaseNotificationBroadcasterEntry> items =
+                entries.iterator();
+            while (items.hasNext()) {
+                BaseNotificationBroadcasterEntry item = items.next();
+                if (item.listener == listener)
+                    items.remove();
+            }
+        }
+
+    }
+
+
+    /**
+     * Send the specified notification to all interested listeners.
+     *
+     * @param notification The notification to be sent
+     */
+    public void sendNotification(Notification notification) {
+
+        synchronized (entries) {
+            for (BaseNotificationBroadcasterEntry item : entries) {
+                if ((item.filter != null) &&
+                    (!item.filter.isNotificationEnabled(notification)))
+                    continue;
+                item.listener.handleNotification(notification, item.handback);
+            }
+        }
+
+    }
+
+}
+
+
+/**
+ * Utility class representing a particular registered listener entry.
+ */
+
+class BaseNotificationBroadcasterEntry {
+
+    public BaseNotificationBroadcasterEntry(NotificationListener listener,
+                                            NotificationFilter filter,
+                                            Object handback) {
+        this.listener = listener;
+        this.filter = filter;
+        this.handback = handback;
+    }
+
+    public NotificationFilter filter = null;
+
+    public Object handback = null;
+
+    public NotificationListener listener = null;
+
+}

java/org/apache/tomcat/util/modeler/FeatureInfo.java

@@ -0,0 +1,83 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+package org.apache.tomcat.util.modeler;
+
+
+import java.io.Serializable;
+
+import javax.management.MBeanFeatureInfo;
+
+
+/**
+ * <p>Convenience base class for <code>AttributeInfo</code> and
+ * <code>OperationInfo</code> classes that will be used to collect configuration
+ * information for the <code>ModelMBean</code> beans exposed for management.</p>
+ *
+ * @author Craig R. McClanahan
+ */
+public class FeatureInfo implements Serializable {
+    static final long serialVersionUID = -911529176124712296L;
+
+    protected String description = null;
+    protected String name = null;
+    protected MBeanFeatureInfo info = null;
+
+    // all have type except Constructor
+    protected String type = null;
+
+
+    // ------------------------------------------------------------- Properties
+
+    /**
+     * @return the human-readable description of this feature.
+     */
+    public String getDescription() {
+        return this.description;
+    }
+
+    public void setDescription(String description) {
+        this.description = description;
+    }
+
+
+    /**
+     * @return the name of this feature, which must be unique among features
+     *  in the same collection.
+     */
+    public String getName() {
+        return this.name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    /**
+     * @return the fully qualified Java class name of this element.
+     */
+    public String getType() {
+        return this.type;
+    }
+
+    public void setType(String type) {
+        this.type = type;
+    }
+
+
+}

java/org/apache/tomcat/util/modeler/LocalStrings.properties

@@ -0,0 +1,17 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+modules.digesterParseError=Error parsing registry data
+modules.readDescriptorsError=Error reading descriptors

java/org/apache/tomcat/util/modeler/LocalStrings_fr.properties

@@ -0,0 +1,17 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+modules.digesterParseError=Erreur lors de l'analyse des données du registre
+modules.readDescriptorsError=Erreur lors de la lecture des descripteurs

java/org/apache/tomcat/util/modeler/LocalStrings_ja.properties

@@ -0,0 +1,17 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+modules.digesterParseError=レジストリデータの解析エラー
+modules.readDescriptorsError=ディスクリプタ読み取り中のエラー

java/org/apache/tomcat/util/modeler/LocalStrings_ko.properties

@@ -0,0 +1,17 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+modules.digesterParseError=레지스트리 데이터를 파싱하는 중 오류 발생
+modules.readDescriptorsError=Descriptor들을 읽는 중 오류 발생

java/org/apache/tomcat/util/modeler/LocalStrings_zh_CN.properties

@@ -0,0 +1,16 @@
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You under the Apache License, Version 2.0
+# (the "License"); you may not use this file except in compliance with
+# the License.  You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+modules.readDescriptorsError=读取描述文件出错

java/org/apache/tomcat/util/modeler/NotificationInfo.java

@@ -0,0 +1,156 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.tomcat.util.modeler;
+
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import javax.management.MBeanNotificationInfo;
+
+/**
+ * <p>Internal configuration information for a <code>Notification</code>
+ * descriptor.</p>
+ *
+ * @author Craig R. McClanahan
+ */
+public class NotificationInfo extends FeatureInfo {
+
+    static final long serialVersionUID = -6319885418912650856L;
+
+    // ----------------------------------------------------- Instance Variables
+
+
+    /**
+     * The <code>ModelMBeanNotificationInfo</code> object that corresponds
+     * to this <code>NotificationInfo</code> instance.
+     */
+    transient MBeanNotificationInfo info = null;
+    protected String notifTypes[] = new String[0];
+    protected final ReadWriteLock notifTypesLock = new ReentrantReadWriteLock();
+
+    // ------------------------------------------------------------- Properties
+
+
+    /**
+     * Override the <code>description</code> property setter.
+     *
+     * @param description The new description
+     */
+    @Override
+    public void setDescription(String description) {
+        super.setDescription(description);
+        this.info = null;
+    }
+
+
+    /**
+     * Override the <code>name</code> property setter.
+     *
+     * @param name The new name
+     */
+    @Override
+    public void setName(String name) {
+        super.setName(name);
+        this.info = null;
+    }
+
+
+    /**
+     * @return the set of notification types for this MBean.
+     */
+    public String[] getNotifTypes() {
+        Lock readLock = notifTypesLock.readLock();
+        readLock.lock();
+        try {
+            return this.notifTypes;
+        } finally {
+            readLock.unlock();
+        }
+    }
+
+
+    // --------------------------------------------------------- Public Methods
+
+
+    /**
+     * Add a new notification type to the set managed by an MBean.
+     *
+     * @param notifType The new notification type
+     */
+    public void addNotifType(String notifType) {
+
+        Lock writeLock = notifTypesLock.writeLock();
+        writeLock.lock();
+        try {
+
+            String results[] = new String[notifTypes.length + 1];
+            System.arraycopy(notifTypes, 0, results, 0, notifTypes.length);
+            results[notifTypes.length] = notifType;
+            notifTypes = results;
+            this.info = null;
+        } finally {
+            writeLock.unlock();
+        }
+    }
+
+
+    /**
+     * Create and return a <code>ModelMBeanNotificationInfo</code> object that
+     * corresponds to the attribute described by this instance.
+     * @return the notification info
+     */
+    public MBeanNotificationInfo createNotificationInfo() {
+
+        // Return our cached information (if any)
+        if (info != null)
+            return info;
+
+        // Create and return a new information object
+        info = new MBeanNotificationInfo
+            (getNotifTypes(), getName(), getDescription());
+        //Descriptor descriptor = info.getDescriptor();
+        //addFields(descriptor);
+        //info.setDescriptor(descriptor);
+        return info;
+
+    }
+
+
+    /**
+     * Return a string representation of this notification descriptor.
+     */
+    @Override
+    public String toString() {
+
+        StringBuilder sb = new StringBuilder("NotificationInfo[");
+        sb.append("name=");
+        sb.append(name);
+        sb.append(", description=");
+        sb.append(description);
+        sb.append(", notifTypes=");
+        Lock readLock = notifTypesLock.readLock();
+        readLock.lock();
+        try {
+            sb.append(notifTypes.length);
+        } finally {
+            readLock.unlock();
+        }
+        sb.append("]");
+        return sb.toString();
+    }
+}

java/org/apache/tomcat/util/modeler/OperationInfo.java

@@ -0,0 +1,172 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.tomcat.util.modeler;
+
+import java.util.Locale;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import javax.management.MBeanOperationInfo;
+import javax.management.MBeanParameterInfo;
+
+/**
+ * <p>Internal configuration information for an <code>Operation</code>
+ * descriptor.</p>
+ *
+ * @author Craig R. McClanahan
+ */
+public class OperationInfo extends FeatureInfo {
+
+    static final long serialVersionUID = 4418342922072614875L;
+
+    // ----------------------------------------------------------- Constructors
+
+    /**
+     * Standard zero-arguments constructor.
+     */
+    public OperationInfo() {
+        super();
+    }
+
+
+    // ----------------------------------------------------- Instance Variables
+
+    protected String impact = "UNKNOWN";
+    protected String role = "operation";
+    protected final ReadWriteLock parametersLock = new ReentrantReadWriteLock();
+    protected ParameterInfo parameters[] = new ParameterInfo[0];
+
+
+    // ------------------------------------------------------------- Properties
+
+    /**
+     * @return the "impact" of this operation, which should be
+     *  a (case-insensitive) string value "ACTION", "ACTION_INFO",
+     *  "INFO", or "UNKNOWN".
+     */
+    public String getImpact() {
+        return this.impact;
+    }
+
+    public void setImpact(String impact) {
+        if (impact == null)
+            this.impact = null;
+        else
+            this.impact = impact.toUpperCase(Locale.ENGLISH);
+    }
+
+
+    /**
+     * @return the role of this operation ("getter", "setter", "operation", or
+     * "constructor").
+     */
+    public String getRole() {
+        return this.role;
+    }
+
+    public void setRole(String role) {
+        this.role = role;
+    }
+
+
+    /**
+     * @return the fully qualified Java class name of the return type for this
+     * operation.
+     */
+    public String getReturnType() {
+        if(type == null) {
+            type = "void";
+        }
+        return type;
+    }
+
+    public void setReturnType(String returnType) {
+        this.type = returnType;
+    }
+
+    /**
+     * @return the set of parameters for this operation.
+     */
+    public ParameterInfo[] getSignature() {
+        Lock readLock = parametersLock.readLock();
+        readLock.lock();
+        try {
+            return this.parameters;
+        } finally {
+            readLock.unlock();
+        }
+    }
+
+    // --------------------------------------------------------- Public Methods
+
+
+    /**
+     * Add a new parameter to the set of arguments for this operation.
+     *
+     * @param parameter The new parameter descriptor
+     */
+    public void addParameter(ParameterInfo parameter) {
+
+        Lock writeLock = parametersLock.writeLock();
+        writeLock.lock();
+        try {
+            ParameterInfo results[] = new ParameterInfo[parameters.length + 1];
+            System.arraycopy(parameters, 0, results, 0, parameters.length);
+            results[parameters.length] = parameter;
+            parameters = results;
+            this.info = null;
+        } finally {
+            writeLock.unlock();
+        }
+    }
+
+
+    /**
+     * Create and return a <code>ModelMBeanOperationInfo</code> object that
+     * corresponds to the attribute described by this instance.
+     * @return the operation info
+     */
+    MBeanOperationInfo createOperationInfo() {
+
+        // Return our cached information (if any)
+        if (info == null) {
+            // Create and return a new information object
+            int impact = MBeanOperationInfo.UNKNOWN;
+            if ("ACTION".equals(getImpact()))
+                impact = MBeanOperationInfo.ACTION;
+            else if ("ACTION_INFO".equals(getImpact()))
+                impact = MBeanOperationInfo.ACTION_INFO;
+            else if ("INFO".equals(getImpact()))
+                impact = MBeanOperationInfo.INFO;
+
+            info = new MBeanOperationInfo(getName(), getDescription(),
+                                          getMBeanParameterInfo(),
+                                          getReturnType(), impact);
+        }
+        return (MBeanOperationInfo)info;
+    }
+
+    protected MBeanParameterInfo[] getMBeanParameterInfo() {
+        ParameterInfo params[] = getSignature();
+        MBeanParameterInfo parameters[] =
+            new MBeanParameterInfo[params.length];
+        for (int i = 0; i < params.length; i++)
+            parameters[i] = params[i].createParameterInfo();
+        return parameters;
+    }
+}

java/org/apache/tomcat/util/modeler/ParameterInfo.java

@@ -0,0 +1,57 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+package org.apache.tomcat.util.modeler;
+
+
+import javax.management.MBeanParameterInfo;
+
+
+/**
+ * <p>Internal configuration information for a <code>Parameter</code>
+ * descriptor.</p>
+ *
+ * @author Craig R. McClanahan
+ */
+public class ParameterInfo extends FeatureInfo {
+    static final long serialVersionUID = 2222796006787664020L;
+    // ----------------------------------------------------------- Constructors
+
+
+    /**
+     * Standard zero-arguments constructor.
+     */
+    public ParameterInfo() {
+        super();
+    }
+
+    /**
+     * Create and return a <code>MBeanParameterInfo</code> object that
+     * corresponds to the parameter described by this instance.
+     * @return a parameter info
+     */
+    public MBeanParameterInfo createParameterInfo() {
+
+        // Return our cached information (if any)
+        if (info == null) {
+            info = new MBeanParameterInfo
+                (getName(), getType(), getDescription());
+        }
+        return (MBeanParameterInfo)info;
+    }
+}

java/org/apache/tomcat/util/modeler/RegistryMBean.java

@@ -0,0 +1,120 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+package org.apache.tomcat.util.modeler;
+
+
+import java.util.List;
+
+import javax.management.ObjectName;
+
+/**
+ * Interface for modeler MBeans.
+ *
+ * This is the main entry point into modeler. It provides methods to create
+ * and manipulate model mbeans and simplify their use.
+ *
+ * Starting with version 1.1, this is no longer a singleton and the static
+ * methods are strongly deprecated. In a container environment we can expect
+ * different applications to use different registries.
+ *
+ * @author Craig R. McClanahan
+ * @author Costin Manolache
+ *
+ * @since 1.1
+ */
+public interface RegistryMBean {
+
+    /**
+     * Invoke an operation on a set of mbeans.
+     *
+     * @param mbeans List of ObjectNames
+     * @param operation Operation to perform. Typically "init" "start" "stop" or "destroy"
+     * @param failFirst Behavior in case of exceptions - if false we'll ignore
+     *      errors
+     * @throws Exception Error invoking operation
+     */
+    public void invoke(List<ObjectName> mbeans, String operation, boolean failFirst)
+            throws Exception;
+
+    /**
+     * Register a bean by creating a modeler mbean and adding it to the
+     * MBeanServer.
+     *
+     * If metadata is not loaded, we'll look up and read a file named
+     * "mbeans-descriptors.ser" or "mbeans-descriptors.xml" in the same package
+     * or parent.
+     *
+     * If the bean is an instance of DynamicMBean. it's metadata will be converted
+     * to a model mbean and we'll wrap it - so modeler services will be supported
+     *
+     * If the metadata is still not found, introspection will be used to extract
+     * it automatically.
+     *
+     * If an mbean is already registered under this name, it'll be first
+     * unregistered.
+     *
+     * If the component implements MBeanRegistration, the methods will be called.
+     * If the method has a method "setRegistry" that takes a RegistryMBean as
+     * parameter, it'll be called with the current registry.
+     *
+     *
+     * @param bean Object to be registered
+     * @param oname Name used for registration
+     * @param type The type of the mbean, as declared in mbeans-descriptors. If
+     * null, the name of the class will be used. This can be used as a hint or
+     * by subclasses.
+     * @throws Exception Error registering MBean
+     *
+     * @since 1.1
+     */
+    public void registerComponent(Object bean, String oname, String type)
+           throws Exception;
+
+    /**
+     * Unregister a component. We'll first check if it is registered,
+     * and mask all errors. This is mostly a helper.
+     *
+     * @param oname The name used by the bean
+     *
+     * @since 1.1
+     */
+    public void unregisterComponent(String oname);
+
+
+     /**
+      * Return an int ID for faster access. Will be used for notifications
+      * and for other operations we want to optimize.
+      *
+      * @param domain Namespace
+      * @param name  Type of the notification
+      * @return  A unique id for the domain:name combination
+      * @since 1.1
+      */
+    public int getId(String domain, String name);
+
+
+    /**
+     * Reset all metadata cached by this registry. Should be called
+     * to support reloading. Existing mbeans will not be affected or modified.
+     *
+     * It will be called automatically if the Registry is unregistered.
+     * @since 1.1
+     */
+    public void stop();
+}

java/org/apache/tomcat/util/modeler/Util.java

@@ -0,0 +1,34 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.apache.tomcat.util.modeler;
+
+public class Util {
+
+    private Util() {
+        // Utility class. Hide default constructor.
+    }
+
+    public static boolean objectNameValueNeedsQuote(String input) {
+        for (int i = 0; i < input.length(); i++) {
+            char ch = input.charAt(i);
+            if (ch == ',' || ch == '=' || ch == ':' || ch == '*' || ch == '?') {
+                return true;
+            }
+        }
+        return false;
+    }
+}

java/org/apache/tomcat/util/modeler/mbeans-descriptors.dtd

@@ -0,0 +1,247 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+
+
+<!--
+     DTD for the Model MBeans Configuration File
+
+     To support validation of your configuration file, include the following
+     DOCTYPE element at the beginning (after the "xml" declaration):
+
+     <!DOCTYPE mbeans-descriptors PUBLIC
+      "-//Apache Software Foundation//DTD Model MBeans Configuration File"
+      "http://jakarta.apache.org/commons/dtds/mbeans-descriptors.dtd">
+-->
+
+
+<!-- ========== Defined Types ============================================= -->
+
+
+<!-- A "Boolean" is the string representation of a boolean (true or false)
+     variable.
+-->
+<!ENTITY % Boolean "(true|false|yes|no)">
+
+
+<!-- A "ClassName" is the fully qualified name of a Java class that is
+     instantiated to provide the functionality of the enclosing element.
+-->
+<!ENTITY % ClassName "CDATA">
+
+
+<!-- A "MethodName" is the name of a constructor or method, which must
+     be legal according to the syntax requirements of the Java language.
+-->
+<!ENTITY % MethodName "CDATA">
+
+
+<!-- A "VariableName" is the name of a variable or parameter, which must
+     be legal according to the syntax requirements of the Java language.
+-->
+<!ENTITY % VariableName "CDATA">
+
+
+<!-- ========== Element Definitions ======================================= -->
+
+
+<!-- The "mbeans-descriptors" element is the root of the configuration file
+     hierarchy, and contains nested elements for all of the other
+     configuration settings.  Remaining element definitions are listed
+     in alphabetical order.
+-->
+<!ELEMENT mbeans-descriptors (mbean*)>
+<!ATTLIST mbeans-descriptors id          ID             #IMPLIED>
+
+
+<!-- The "attribute" element describes a JavaBeans property of an MBean.
+     The following attributes are supported:
+
+     description      Human-readable description of this attribute.
+
+     displayName      Display name of this attribute.
+
+     getMethod        Name of the property getter method, if it does
+                      not follow standard JavaBeans naming patterns.
+
+     is               Boolean value indicating whether or not this
+                      attribute is a boolean with an "is" getter method.
+                      By default, this is set to "false".
+
+     name             Name of this JavaBeans property, conforming to
+                      standard naming design patterns.
+
+     readable         Boolean value indicating whether or not this
+                      attribute is readable by management applications.
+                      By default, this is set to "true".
+
+     setMethod        Name of the property setter method, if it does
+                      not follow standard JavaBeans naming patterns.
+
+     type             Fully qualified Java class name of this attribute.
+
+     writeable        Boolean value indicating whether or not this
+                      attribute is writeable by management applications.
+                      By default, this is set to "true".
+-->
+<!ELEMENT attribute (descriptor?)>
+<!ATTLIST attribute         id           ID             #IMPLIED>
+<!ATTLIST attribute         description  CDATA          #IMPLIED>
+<!ATTLIST attribute         displayName  CDATA          #IMPLIED>
+<!ATTLIST attribute         getMethod    %MethodName;   #IMPLIED>
+<!ATTLIST attribute         is           %Boolean;      #IMPLIED>
+<!ATTLIST attribute         name         %VariableName; #IMPLIED>
+<!ATTLIST attribute         readable     %Boolean;      #IMPLIED>
+<!ATTLIST attribute         setMethod    %MethodName;   #IMPLIED>
+<!ATTLIST attribute         type         %ClassName;    #IMPLIED>
+<!ATTLIST attribute         writeable    %Boolean;      #IMPLIED>
+
+
+<!-- The "constructor" element describes a public constructor for the
+     underlying actual class.  It may contain nested "parameter" elements
+     for the various arguments to this constructor.  The following attributes
+     are supported:
+
+     displayName      Display name of this constructor.
+
+     name             Name of this constructor (by Java convention, this must
+                      be the same as the base class name).
+-->
+<!ELEMENT constructor (descriptor?, parameter*)>
+<!ATTLIST constructor       id           ID             #IMPLIED>
+<!ATTLIST constructor       displayName  CDATA          #IMPLIED>
+<!ATTLIST constructor       name         %VariableName; #IMPLIED>
+
+
+<!-- The "descriptor" element groups a set of descriptor fields whose
+     values will be included in the Descriptor for the corresponding
+     metadata info classes.
+-->
+<!ELEMENT descriptor (field*)>
+<!ATTLIST descriptor        id           ID             #IMPLIED>
+
+
+<!-- The "field" element represents a single name/value pair that will
+     be included in the Descriptor corresponding to our enclosing
+     "descriptor" element.  The following attributes are supported:
+
+     name             Field name of the field to be included
+
+     value            Field value of the field to be included
+                      (will be stored as a String)
+-->
+<!ELEMENT field EMPTY>
+<!ATTLIST field             id           ID             #IMPLIED>
+<!ATTLIST field             name         CDATA          #REQUIRED>
+<!ATTLIST field             value        CDATA          #REQUIRED>
+
+
+
+<!-- The "mbean" element describes a particular JMX ModelMBean implementation,
+     including the information necessary to construct the corresponding
+     ModelMBeanInfo structures.  The following attributes are supported:
+
+     className        Fully qualified Java class name of the ModelMBean
+                      implementation class.  If not specified, the standard
+                      implementation provided by JMX will be utilized.
+
+     description      Human-readable description of this managed bean.
+
+     domain           The JMX MBeanServer domain in which the ModelMBean
+                      created by this managed bean should be registered,
+                      when creating its ObjectName.
+
+     group            Optional name of a "grouping classification" that can
+                      be used to select groups of similar MBean implementation
+                      classes.
+
+     name             Unique name of this MBean (normally corresponds to the
+                      base class name of the corresponding server component).
+
+     type             Fully qualified Java class name of the underlying
+                      managed resource implementation class.
+-->
+<!ELEMENT mbean (descriptor?, attribute*, constructor*, notification*, operation*)>
+<!ATTLIST mbean             id           ID             #IMPLIED>
+<!ATTLIST mbean             className    %ClassName;    #IMPLIED>
+<!ATTLIST mbean             description  CDATA          #IMPLIED>
+<!ATTLIST mbean             domain       CDATA          #IMPLIED>
+<!ATTLIST mbean             group        CDATA          #IMPLIED>
+<!ATTLIST mbean             name         %MethodName;   #IMPLIED>
+<!ATTLIST mbean             type         %ClassName;    #IMPLIED>
+
+
+<!-- The "notification" element describes the notification types that are
+     generated by a particular managed bean.  The following attributes
+     are supported:
+
+     description      Human-readable description of these notification events.
+
+     name             Name of this set of notification event types.
+-->
+<!ELEMENT notification (descriptor?, notification-type*)>
+<!ATTLIST notification      id           ID             #IMPLIED>
+<!ATTLIST notification      description  CDATA          #IMPLIED>
+<!ATTLIST notification      name         %VariableName; #IMPLIED>
+
+
+<!-- The nested content of the "notification-type" element is the event string
+     of an event that can be emitted by this MBean.
+-->
+<!ELEMENT notification-type (#PCDATA)>
+<!ATTLIST notification-type id           ID             #IMPLIED>
+
+
+<!-- The "operation" element describes a the signature of a public method
+     that is accessible to management applications.  The following attributes
+     are supported:
+
+     description      Human-readable description of this operation.
+
+     impact           Indication of the impact of this method:
+                      ACTION (write like), ACTION-INFO (write+read like)
+                      INFO (read like), or UNKNOWN.
+
+     name             Name of this public method.
+
+     returnType       Fully qualified Java class name of the return
+                      type of this method.
+-->
+<!ELEMENT operation   (descriptor?, parameter*)>
+<!ATTLIST operation         id           ID             #IMPLIED>
+<!ATTLIST operation         description  CDATA          #IMPLIED>
+<!ATTLIST operation         impact       CDATA          #IMPLIED>
+<!ATTLIST operation         name         %VariableName; #IMPLIED>
+<!ATTLIST operation         returnType   %ClassName;    #IMPLIED>
+
+
+<!-- The "parameter" element describes a single argument that will be passed
+     to a constructor or operation.  The following attributes are supported:
+
+     description      Human-readable description of this parameter.
+
+     name             Java language name of this parameter.
+
+     type             Fully qualified Java class name of this parameter.
+-->
+<!ELEMENT parameter EMPTY>
+<!ATTLIST parameter         id           ID             #IMPLIED>
+<!ATTLIST parameter         description  CDATA          #IMPLIED>
+<!ATTLIST parameter         name         %VariableName; #IMPLIED>
+<!ATTLIST parameter         type         %ClassName;    #IMPLIED>
+
+

java/org/apache/tomcat/util/modeler/modules/MbeansDescriptorsDigesterSource.java

@@ -0,0 +1,182 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+package org.apache.tomcat.util.modeler.modules;
+
+import java.io.InputStream;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.List;
+
+import javax.management.ObjectName;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.digester.Digester;
+import org.apache.tomcat.util.modeler.ManagedBean;
+import org.apache.tomcat.util.modeler.Registry;
+
+public class MbeansDescriptorsDigesterSource extends ModelerSource
+{
+    private static final Log log =
+            LogFactory.getLog(MbeansDescriptorsDigesterSource.class);
+    private static final Object dLock = new Object();
+
+    private Registry registry;
+    private final List<ObjectName> mbeans = new ArrayList<>();
+    private static Digester digester = null;
+
+    private static Digester createDigester() {
+
+        Digester digester = new Digester();
+        digester.setNamespaceAware(false);
+        digester.setValidating(false);
+        URL url = Registry.getRegistry(null, null).getClass().getResource
+            ("/org/apache/tomcat/util/modeler/mbeans-descriptors.dtd");
+        digester.register
+            ("-//Apache Software Foundation//DTD Model MBeans Configuration File",
+                url.toString());
+
+        // Configure the parsing rules
+        digester.addObjectCreate
+            ("mbeans-descriptors/mbean",
+            "org.apache.tomcat.util.modeler.ManagedBean");
+        digester.addSetProperties
+            ("mbeans-descriptors/mbean");
+        digester.addSetNext
+            ("mbeans-descriptors/mbean",
+                "add",
+            "java.lang.Object");
+
+        digester.addObjectCreate
+            ("mbeans-descriptors/mbean/attribute",
+            "org.apache.tomcat.util.modeler.AttributeInfo");
+        digester.addSetProperties
+            ("mbeans-descriptors/mbean/attribute");
+        digester.addSetNext
+            ("mbeans-descriptors/mbean/attribute",
+                "addAttribute",
+            "org.apache.tomcat.util.modeler.AttributeInfo");
+
+        digester.addObjectCreate
+            ("mbeans-descriptors/mbean/notification",
+            "org.apache.tomcat.util.modeler.NotificationInfo");
+        digester.addSetProperties
+            ("mbeans-descriptors/mbean/notification");
+        digester.addSetNext
+            ("mbeans-descriptors/mbean/notification",
+                "addNotification",
+            "org.apache.tomcat.util.modeler.NotificationInfo");
+
+        digester.addObjectCreate
+            ("mbeans-descriptors/mbean/notification/descriptor/field",
+            "org.apache.tomcat.util.modeler.FieldInfo");
+        digester.addSetProperties
+            ("mbeans-descriptors/mbean/notification/descriptor/field");
+        digester.addSetNext
+            ("mbeans-descriptors/mbean/notification/descriptor/field",
+                "addField",
+            "org.apache.tomcat.util.modeler.FieldInfo");
+
+        digester.addCallMethod
+            ("mbeans-descriptors/mbean/notification/notification-type",
+                "addNotifType", 0);
+
+        digester.addObjectCreate
+            ("mbeans-descriptors/mbean/operation",
+            "org.apache.tomcat.util.modeler.OperationInfo");
+        digester.addSetProperties
+            ("mbeans-descriptors/mbean/operation");
+        digester.addSetNext
+            ("mbeans-descriptors/mbean/operation",
+                "addOperation",
+            "org.apache.tomcat.util.modeler.OperationInfo");
+
+        digester.addObjectCreate
+            ("mbeans-descriptors/mbean/operation/descriptor/field",
+            "org.apache.tomcat.util.modeler.FieldInfo");
+        digester.addSetProperties
+            ("mbeans-descriptors/mbean/operation/descriptor/field");
+        digester.addSetNext
+            ("mbeans-descriptors/mbean/operation/descriptor/field",
+                "addField",
+            "org.apache.tomcat.util.modeler.FieldInfo");
+
+        digester.addObjectCreate
+            ("mbeans-descriptors/mbean/operation/parameter",
+            "org.apache.tomcat.util.modeler.ParameterInfo");
+        digester.addSetProperties
+            ("mbeans-descriptors/mbean/operation/parameter");
+        digester.addSetNext
+            ("mbeans-descriptors/mbean/operation/parameter",
+                "addParameter",
+            "org.apache.tomcat.util.modeler.ParameterInfo");
+
+        return digester;
+
+    }
+
+    public void setRegistry(Registry reg) {
+        this.registry=reg;
+    }
+
+
+    public void setSource( Object source ) {
+        this.source=source;
+    }
+
+    @Override
+    public List<ObjectName> loadDescriptors( Registry registry, String type,
+            Object source) throws Exception {
+        setRegistry(registry);
+        setSource(source);
+        execute();
+        return mbeans;
+    }
+
+    public void execute() throws Exception {
+        if (registry == null) {
+            registry = Registry.getRegistry(null, null);
+        }
+
+        InputStream stream = (InputStream) source;
+
+        List<ManagedBean> loadedMbeans = new ArrayList<>();
+        synchronized(dLock) {
+            if (digester == null) {
+                digester = createDigester();
+            }
+
+            // Process the input file to configure our registry
+            try {
+                // Push our registry object onto the stack
+                digester.push(loadedMbeans);
+                digester.parse(stream);
+            } catch (Exception e) {
+                log.error(sm.getString("modules.digesterParseError"), e);
+                throw e;
+            } finally {
+                digester.reset();
+            }
+
+        }
+        for (ManagedBean loadedMbean : loadedMbeans) {
+            registry.addManagedBean(loadedMbean);
+        }
+    }
+}

java/org/apache/tomcat/util/modeler/modules/MbeansDescriptorsIntrospectionSource.java

@@ -0,0 +1,392 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.tomcat.util.modeler.modules;
+
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.math.BigDecimal;
+import java.math.BigInteger;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.Hashtable;
+import java.util.List;
+import java.util.Map.Entry;
+
+import javax.management.ObjectName;
+
+import org.apache.juli.logging.Log;
+import org.apache.juli.logging.LogFactory;
+import org.apache.tomcat.util.modeler.AttributeInfo;
+import org.apache.tomcat.util.modeler.ManagedBean;
+import org.apache.tomcat.util.modeler.OperationInfo;
+import org.apache.tomcat.util.modeler.ParameterInfo;
+import org.apache.tomcat.util.modeler.Registry;
+
+public class MbeansDescriptorsIntrospectionSource extends ModelerSource
+{
+    private static final Log log = LogFactory.getLog(MbeansDescriptorsIntrospectionSource.class);
+
+    private Registry registry;
+    private String type;
+    private final List<ObjectName> mbeans = new ArrayList<>();
+
+    public void setRegistry(Registry reg) {
+        this.registry=reg;
+    }
+
+    /**
+     * Used if a single component is loaded
+     *
+     * @param type The type
+     */
+    public void setType( String type ) {
+       this.type=type;
+    }
+
+    public void setSource( Object source ) {
+        this.source=source;
+    }
+
+    @Override
+    public List<ObjectName> loadDescriptors(Registry registry, String type,
+            Object source) throws Exception {
+        setRegistry(registry);
+        setType(type);
+        setSource(source);
+        execute();
+        return mbeans;
+    }
+
+    public void execute() throws Exception {
+        if( registry==null ) registry=Registry.getRegistry(null, null);
+        try {
+            ManagedBean managed = createManagedBean(registry, null,
+                    (Class<?>)source, type);
+            if( managed==null ) return;
+            managed.setName( type );
+
+            registry.addManagedBean(managed);
+
+        } catch( Exception ex ) {
+            log.error(sm.getString("modules.readDescriptorsError"), ex);
+        }
+    }
+
+
+
+    // ------------ Implementation for non-declared introspection classes
+
+    private static final Hashtable<String,String> specialMethods = new Hashtable<>();
+    static {
+        specialMethods.put( "preDeregister", "");
+        specialMethods.put( "postDeregister", "");
+    }
+
+    private static final Class<?>[] supportedTypes  = new Class[] {
+        Boolean.class,
+        Boolean.TYPE,
+        Byte.class,
+        Byte.TYPE,
+        Character.class,
+        Character.TYPE,
+        Short.class,
+        Short.TYPE,
+        Integer.class,
+        Integer.TYPE,
+        Long.class,
+        Long.TYPE,
+        Float.class,
+        Float.TYPE,
+        Double.class,
+        Double.TYPE,
+        String.class,
+        String[].class,
+        BigDecimal.class,
+        BigInteger.class,
+        ObjectName.class,
+        Object[].class,
+        java.io.File.class,
+    };
+
+    /**
+     * Check if this class is one of the supported types.
+     * If the class is supported, returns true.  Otherwise,
+     * returns false.
+     * @param ret The class to check
+     * @return boolean True if class is supported
+     */
+    private boolean supportedType(Class<?> ret) {
+        for (int i = 0; i < supportedTypes.length; i++) {
+            if (ret == supportedTypes[i]) {
+                return true;
+            }
+        }
+        if (isBeanCompatible(ret)) {
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Check if this class conforms to JavaBeans specifications.
+     * If the class is conformant, returns true.
+     *
+     * @param javaType The class to check
+     * @return boolean True if the class is compatible.
+     */
+    private boolean isBeanCompatible(Class<?> javaType) {
+        // Must be a non-primitive and non array
+        if (javaType.isArray() || javaType.isPrimitive()) {
+            return false;
+        }
+
+        // Anything in the java or javax package that
+        // does not have a defined mapping is excluded.
+        if (javaType.getName().startsWith("java.") ||
+            javaType.getName().startsWith("javax.")) {
+            return false;
+        }
+
+        try {
+            javaType.getConstructor(new Class[]{});
+        } catch (java.lang.NoSuchMethodException e) {
+            return false;
+        }
+
+        // Make sure superclass is compatible
+        Class<?> superClass = javaType.getSuperclass();
+        if (superClass != null &&
+            superClass != java.lang.Object.class &&
+            superClass != java.lang.Exception.class &&
+            superClass != java.lang.Throwable.class) {
+            if (!isBeanCompatible(superClass)) {
+                return false;
+            }
+        }
+        return true;
+    }
+
+    /**
+     * Process the methods and extract 'attributes', methods, etc.
+     *
+     * @param realClass The class to process
+     * @param methods The methods to process
+     * @param attMap The attribute map (complete)
+     * @param getAttMap The readable attributes map
+     * @param setAttMap The settable attributes map
+     * @param invokeAttMap The invokable attributes map
+     */
+    private void initMethods(Class<?> realClass, Method methods[], Hashtable<String,Method> attMap,
+            Hashtable<String,Method> getAttMap, Hashtable<String,Method> setAttMap,
+            Hashtable<String,Method> invokeAttMap) {
+
+        for (int j = 0; j < methods.length; ++j) {
+            String name = methods[j].getName();
+
+            if (Modifier.isStatic(methods[j].getModifiers())) {
+                continue;
+            }
+            if (!Modifier.isPublic(methods[j].getModifiers())) {
+                if (log.isDebugEnabled()) {
+                    log.debug("Not public " + methods[j] );
+                }
+                continue;
+            }
+            if (methods[j].getDeclaringClass() == Object.class) {
+                continue;
+            }
+            Class<?> params[] = methods[j].getParameterTypes();
+
+            if (name.startsWith("get") && params.length==0) {
+                Class<?> ret = methods[j].getReturnType();
+                if (!supportedType(ret)) {
+                    if (log.isDebugEnabled()) {
+                        log.debug("Unsupported type " + methods[j]);
+                    }
+                    continue;
+                }
+                name=unCapitalize(name.substring(3));
+
+                getAttMap.put(name, methods[j]);
+                // just a marker, we don't use the value
+                attMap.put(name, methods[j]);
+            } else if(name.startsWith("is") && params.length == 0) {
+                Class<?> ret = methods[j].getReturnType();
+                if (Boolean.TYPE != ret) {
+                    if (log.isDebugEnabled()) {
+                        log.debug("Unsupported type " + methods[j] + " " + ret );
+                    }
+                    continue;
+                }
+                name = unCapitalize(name.substring(2));
+
+                getAttMap.put(name, methods[j]);
+                // just a marker, we don't use the value
+                attMap.put(name, methods[j]);
+
+            } else if (name.startsWith("set") && params.length == 1) {
+                if (!supportedType(params[0])) {
+                    if (log.isDebugEnabled()) {
+                        log.debug("Unsupported type " + methods[j] + " " + params[0]);
+                    }
+                    continue;
+                }
+                name = unCapitalize(name.substring(3));
+                setAttMap.put(name, methods[j]);
+                attMap.put(name, methods[j]);
+            } else {
+                if (params.length == 0) {
+                    if (specialMethods.get(methods[j].getName()) != null) {
+                        continue;
+                    }
+                    invokeAttMap.put(name, methods[j]);
+                } else {
+                    boolean supported = true;
+                    for (int i = 0; i < params.length; i++ ) {
+                        if (!supportedType(params[i])) {
+                            supported = false;
+                            break;
+                        }
+                    }
+                    if (supported) {
+                        invokeAttMap.put( name, methods[j]);
+                    }
+                }
+            }
+        }
+    }
+
+    /**
+     * XXX Find if the 'className' is the name of the MBean or
+     *       the real class ( I suppose first )
+     * XXX Read (optional) descriptions from a .properties, generated
+     *       from source
+     * XXX Deal with constructors
+     *
+     * @param registry The Bean registry (not used)
+     * @param domain The bean domain (not used)
+     * @param realClass The class to analyze
+     * @param type The bean type
+     * @return ManagedBean The create MBean
+     */
+    public ManagedBean createManagedBean(Registry registry, String domain,
+                                         Class<?> realClass, String type)
+    {
+        ManagedBean mbean= new ManagedBean();
+
+        Method methods[]=null;
+
+        Hashtable<String,Method> attMap = new Hashtable<>();
+        // key: attribute val: getter method
+        Hashtable<String,Method> getAttMap = new Hashtable<>();
+        // key: attribute val: setter method
+        Hashtable<String,Method> setAttMap = new Hashtable<>();
+        // key: operation val: invoke method
+        Hashtable<String,Method> invokeAttMap = new Hashtable<>();
+
+        methods = realClass.getMethods();
+
+        initMethods(realClass, methods, attMap, getAttMap, setAttMap, invokeAttMap );
+
+        try {
+
+            Enumeration<String> en = attMap.keys();
+            while( en.hasMoreElements() ) {
+                String name = en.nextElement();
+                AttributeInfo ai=new AttributeInfo();
+                ai.setName( name );
+                Method gm = getAttMap.get(name);
+                if( gm!=null ) {
+                    //ai.setGetMethodObj( gm );
+                    ai.setGetMethod( gm.getName());
+                    Class<?> t=gm.getReturnType();
+                    if( t!=null )
+                        ai.setType( t.getName() );
+                }
+                Method sm = setAttMap.get(name);
+                if( sm!=null ) {
+                    //ai.setSetMethodObj(sm);
+                    Class<?> t = sm.getParameterTypes()[0];
+                    if( t!=null )
+                        ai.setType( t.getName());
+                    ai.setSetMethod( sm.getName());
+                }
+                ai.setDescription("Introspected attribute " + name);
+                if( log.isDebugEnabled()) log.debug("Introspected attribute " +
+                        name + " " + gm + " " + sm);
+                if( gm==null )
+                    ai.setReadable(false);
+                if( sm==null )
+                    ai.setWriteable(false);
+                if( sm!=null || gm!=null )
+                    mbean.addAttribute(ai);
+            }
+
+            // This map is populated by iterating the methods (which end up as
+            // values in the Map) and obtaining the key from the value. It is
+            // impossible for a key to be associated with a null value.
+            for (Entry<String,Method> entry : invokeAttMap.entrySet()) {
+                String name = entry.getKey();
+                Method m = entry.getValue();
+
+                OperationInfo op=new OperationInfo();
+                op.setName(name);
+                op.setReturnType(m.getReturnType().getName());
+                op.setDescription("Introspected operation " + name);
+                Class<?> parms[] = m.getParameterTypes();
+                for(int i=0; i<parms.length; i++ ) {
+                    ParameterInfo pi=new ParameterInfo();
+                    pi.setType(parms[i].getName());
+                    pi.setName(("param" + i).intern());
+                    pi.setDescription(("Introspected parameter param" + i).intern());
+                    op.addParameter(pi);
+                }
+                mbean.addOperation(op);
+            }
+
+            if( log.isDebugEnabled())
+                log.debug("Setting name: " + type );
+            mbean.setName( type );
+
+            return mbean;
+        } catch( Exception ex ) {
+            ex.printStackTrace();
+            return null;
+        }
+    }
+
+
+    // -------------------- Utils --------------------
+    /**
+     * Converts the first character of the given
+     * String into lower-case.
+     *
+     * @param name The string to convert
+     * @return String
+     */
+    private static String unCapitalize(String name) {
+        if (name == null || name.length() == 0) {
+            return name;
+        }
+        char chars[] = name.toCharArray();
+        chars[0] = Character.toLowerCase(chars[0]);
+        return new String(chars);
+    }
+
+}
+

java/org/apache/tomcat/util/modeler/modules/ModelerSource.java

@@ -0,0 +1,44 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.tomcat.util.modeler.modules;
+
+import java.util.List;
+
+import javax.management.ObjectName;
+
+import org.apache.tomcat.util.modeler.Registry;
+import org.apache.tomcat.util.res.StringManager;
+
+/**
+ * Source for descriptor data. More sources can be added.
+ */
+public abstract class ModelerSource {
+    protected static final StringManager sm = StringManager.getManager(Registry.class);
+    protected Object source;
+
+    /**
+     * Load data, returns a list of items.
+     *
+     * @param registry The registry
+     * @param type The bean registry type
+     * @param source Introspected object or some other source
+     * @return a list of object names
+     * @throws Exception Error loading descriptors
+     */
+    public abstract List<ObjectName> loadDescriptors(Registry registry,
+            String type, Object source) throws Exception;
+}

java/org/apache/tomcat/util/modeler/modules/package.html

@@ -0,0 +1,59 @@
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<html>
+<head>
+<title>org.apache.commons.modeler.modules</title>
+</head>
+<body>
+<p>Implementation classes - should not be used directly. The API is not stable
+but eventually the code will be refactored as a collection of mbeans that will be useable
+( more or less ) independently.</p>
+
+<p>The MbeanDescriptors* classes are used to extract metadata from different sources. They
+are result of few stages of refactoring - now they look very similar with ant tasks and are
+close to normal mbeans, with an execute() method. DOM, SER, Introspection and Dynamic mbean
+will load metadata from the corresponding sources.
+</p>
+
+<p>MbeansSource will load an extended MLET file, similar with jboss. It is not completely
+implemented - only modeler mbeans and dynamic mbeans are loaded. The important characteristic
+is that all declared mbeans will be registered in the mbean server as model mbeans. For
+regular java classes, the description will be used to construct the model mbean. DynamicMbeans
+metadata will be converted to model mbean and the model mbean wrapper will be loaded.</p>
+
+<p>The goal of MbeansSource is to implement a simple persistence mechanism. Since all components
+are model mbeans, we can detect all changes. The source will be loaded as DOM and modifications
+will be made to the tree. The save() method will save the DOM tree - preserving all comments
+and having only the changes that are needed.</p>
+
+<p>There are few remaining issues. First, we need to use the persistence metadata to avoid
+saving transient fields ( we save an attribute when we detect a change - but we don't know
+if this attribute should be saved ). The solution is to use the persistence fields in the
+spec - with some reasonable defaults or patterns for introspection or backward compat.
+</p>
+
+<p>Another problem is implementing adding and removing components. In catalina, a
+factory is used to create the components, and save will operate on all mbeans.
+For creation we need to also use a factory - using the "Type" as a parameter. This
+will also work very well with Ant1.6 where we can use the component factory to
+do a "natural" mapping ( i.e. mbeans can be treated as tasks, with attributes as
+task attributes ). The second part can be solve by either using a parameter on
+the factory method ( saveTo ? ), or by having a single mbeans source per domain.
+</p>
+
+</body>
+</html>

java/org/apache/tomcat/util/modeler/package.html

@@ -0,0 +1,248 @@
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one or more
+  contributor license agreements.  See the NOTICE file distributed with
+  this work for additional information regarding copyright ownership.
+  The ASF licenses this file to You under the Apache License, Version 2.0
+  (the "License"); you may not use this file except in compliance with
+  the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<html>
+<head>
+<title>Package Documentation for COMMONS-MODELER</title>
+</head>
+<body bgcolor="white">
+<p>The <em>Modeler</em> component of the Commons project
+offers convenient support for configuring and instantiating Model MBeans
+(management beans), as described in the JMX Specification.  It is typically
+used within a server-based application that wants to expose management
+features via JMX.  See the
+<a href="http://java.sun.com/products/JavaManagement/download.html">
+JMX Specification (Version 1.1)</a> for more information about Model MBeans
+and other JMX concepts.</p>
+
+<p>Model MBeans are very powerful - and the JMX specification includes a
+mechanism to use a standard JMX-provided base class to satisfy many of the
+requirements, without having to create custom Model MBean implementation
+classes yourself.  However, one of the requirements in creating such a
+Model MBean is to create the corresponding metadata information (i.e. an
+implementation of the
+<code>javax.management.modelmbean.ModelMBeanInfo</code> interface and its
+corresponding subordinate interfaces).  Creating this information can be
+tedious and error prone.  The <em>Modeler</em> package makes the process
+much simpler, because the required information is constructed dynamically
+from an easy-to-understand XML description of the metadata.  Once you have
+the metadata defined, and registered at runtime in the provided
+<a href="Registry.html">Registry</a>, <em>Modeler</em> also supports
+convenient factory methods to instantiate new Model MBean instances for you.
+</p>
+
+<p>The steps required to use Modeler in your server-based application are
+described in detail below.  You can find some simple usage code in the unit
+tests that come with Modeler (in the <code>src/test</code> subdirectory of the
+source distribution), and much more complex usage code in Tomcat 4.1 (in the
+<code>org.apache.catalina.mbeans</code> package).</p>. More advanced uses can
+be found in Tomcat 5.
+
+
+<h2>1.  Acquire a JMX Implementation</h2>
+
+<p><em>Modeler</em> has been tested with different JMX implementations:
+<ul>
+<li>JMX Reference Implementation (version 1.0.1 or later) -
+    <a href="http://java.sun.com/products/JavaManagement/download.html">
+    http://java.sun.com/products/JavaManagement/download.html</a></li>
+<li>MX4J (version 1.1 or later) -
+    <a href="http://mx4j.sourceforge.net/">http://mx4j.sourceforge.net</a></li>
+<li>JBoss MX
+    <a href="http://www.jboss.org/">http://www.jboss.org</a></li>
+</ul>
+
+<p>After unpacking the release, you will need to ensure that the appropriate
+JAR file (<code>jmxri.jar</code> or <code>mx4j.jar</code>) is included on your
+compilation classpath, and in the classpath of your server application when it
+is executed.</p>
+
+
+<h2>2.  Create a Modeler Configuration File</h2>
+
+<p><em>Modeler</em> requires that you construct a configuration file that
+describes the metadata ultimately need to construct the
+<code>javax.management.modelmbean.ModelMBeanInfo</code> structure that is
+required by JMX.  Your XML file must conform to the
+<a href="../../../../../../mbeans-descriptors.dtd">mbeans-descriptors.dtd</a>
+DTD that defines the acceptable structure.</p>
+
+<p>Fundamentally, you will be constructing an <code>&lt;mbean&gt;</code>
+element for each type of Model MBean that a registry will know how to create.
+Nested within this element will be other elements describing the constructors,
+attributes, operations, and notifications associated with this MBean.  See
+the comments in the DTD for detailed information about the valid attributes
+and their meanings.</p>
+
+<p>A simple example configuration file might include the following components
+(abstracted from the real definitions found in Tomcat 4.1's use of Modeler):
+</p>
+<pre>
+
+  &lt;?xml version="1.0"?&gt;
+  &lt;!DOCTYPE mbeans-descriptors PUBLIC
+   "-//Apache Software Foundation//DTD Model MBeans Configuration File"
+   "http://jakarta.apache.org/commons/dtds/mbeans-descriptors.dtd"&gt;
+
+  &lt;mbeans-descriptors&gt;
+
+    &lt;!-- ... other MBean definitions ... --&gt;
+
+    &lt;mbean         name="Group"
+              className="org.apache.catalina.mbeans.GroupMBean"
+            description="Group from a user database"
+                 domain="Users"
+                  group="Group"
+                   type="org.apache.catalina.Group"&gt;
+
+      &lt;attribute   name="description"
+            description="Description of this group"
+                   type="java.lang.String"/&gt;
+
+      &lt;attribute   name="groupname"
+            description="Group name of this group"
+                   type="java.lang.String"/&gt;
+
+      &lt;attribute   name="roles"
+            description="MBean Names of roles for this group"
+                   type="java.lang.String[]"
+              writeable="false"/&gt;
+
+      &lt;attribute   name="users"
+            description="MBean Names of user members of this group"
+                   type="java.lang.String[]"
+              writeable="false"/&gt;
+
+      &lt;operation   name="addRole"
+            description="Add a new authorized role for this group"
+                 impact="ACTION"
+             returnType="void"&gt;
+        &lt;parameter name="role"
+            description="Role to be added"
+                   type="java.lang.String"/&gt;
+      &lt;/operation&gt;
+
+      &lt;operation   name="removeRole"
+            description="Remove an old authorized role for this group"
+                 impact="ACTION"
+             returnType="void"&gt;
+        &lt;parameter name="role"
+            description="Role to be removed"
+                   type="java.lang.String"/&gt;
+      &lt;/operation&gt;
+
+      &lt;operation   name="removeRoles"
+            description="Remove all authorized roles for this group"
+                 impact="ACTION"
+             returnType="void"&gt;
+      &lt;/operation&gt;
+
+    &lt;/mbean&gt;
+
+    &lt;!-- ... other MBean definitions ... --&gt;
+
+  &lt;/mbeans-descriptors&gt;
+
+</pre>
+
+<p>This MBean represents an instance of <em>org.apache.catalina.Group</em>,
+which is an entity representing a group of users (with a shared set of security
+roles that all users in the group inherit) in a user database.  This MBean
+advertises support for four attributes (description, groupname, roles, and
+users) that roughly correspond to JavaBean properties.  By default, attributes
+are assumed to have read/write access.  For this particular MBean, the roles
+and users attributes are read-only (<code>writeable="false"</code>).  Finally,
+this MBean supports three operations (addRole, removeRole, and
+removeRoles) that roughly correspond to JavaBean methods on the underlying
+component.</p>
+
+<p>In general, <em>Modeler</em> provides a standard ModelMBean implementation
+that simply passes on JMX calls on attributes and operations directly through
+to the managed component that the ModelMBean is associated with.  For special
+case requirements, you can define a subclass of
+<a href="BaseModelMBean.html">BaseModelMBean</a> that provides override
+methods for one or more of these attributes (i.e. the property getter and/or
+setter methods) and operations (i.e. direct method calls).
+
+<p>For this particular MBean, a custom BaseModelMBean implementation subclass
+is described (<code>org.apache.catalina.mbeans.GroupMBean</code>) is
+configured.  It was necessary in this particular case because several of the
+underlying Catalina component's methods deal with internal objects or arrays of
+objects, rather than just the Strings and primitives that are supported by all
+JMX clients.  Thus, the following method on the <code>Group</code> interface:
+</p>
+<pre>
+    public void addRole(Role role);
+</pre>
+<p>is represented, in the MBean, by an <code>addRole</code> method that takes
+a String argument representing the role name of the required role.  The MBean's
+implementation class acts as an adapter, and looks up the required Role
+object (by name) before calling the <code>addRole</code> method on the
+underlying <code>Group</code> instance within the Server.</p>
+
+
+<h2>3.  Create Modeler Registry at Startup Time</h2>
+
+<p>The metadata information, and the corresponding Model MBean factory, is
+represented at runtime in an instance of <a href="Registry.html">Registry</a>
+whose contents are initialized from the configuration file prepared as was
+described above.  Typically, such a file will be included in the JAR file
+containing the MBean implementation classes themselves, and loaded as follows:
+</p>
+<pre>
+    URL url= this.getClass().getResource
+      ("/com/mycompany/mypackage/mbeans-descriptors.xml");
+    Registry registry = Registry.getRegistry();
+    registry.loadMetadata(url);
+</pre>
+
+<p>Besides using the configuration file, it is possible to configure the
+registry metadata by hand, using the <code>addManagedBean()</code> and
+<code>removeManagedBean()</code> methods.  However, most users will find
+the standard support for loading a configuration file to be convenient
+and sufficient.</p>
+
+<p>Modeler will also look for an mbeans-descriptors.xml in the same package
+with the class being registered and in its parent. If no metadata is found,
+modeler will use a number of simple patterns, similar with the ones used by
+ant, to determine a reasonable metadata</p>
+
+<p>In a future version we should also support xdoclet-based generation of the
+descriptors</p>
+
+
+<h2>4.  Instantiate Model MBeans As Needed</h2>
+
+<p>When your server application needs to instantiate a new MBean and register
+it with the corresponding <code>MBeanServer</code>, it can execute code like
+this:</p>
+
+<pre>
+  Group group = ... managed component instance ...;
+
+  MBeanServer mserver = registry.getMBeanServer();
+
+  String oname="myDomain:type=Group,name=myGroup";
+
+  registry.registerComponent( group, oname, "Group" );
+</pre>
+
+<p>After the Model MBean has been created and registered, it is accessible to
+JMX clients through the standard JMX client APIs.
+</p>
+
+</body>
+</html>