init

java/javax/el/Jre9Compat.java

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+/*
+ *  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 javax.el;
+
+import java.lang.reflect.AccessibleObject;
+import java.lang.reflect.Method;
+
+/*
+ * This is a cut down version of org.apache.tomcat.util.Jre9Compat that provides
+ * only the methods required by the EL implementation.
+ *
+ * This class is duplicated in org.apache.el.util
+ * When making changes keep the two in sync.
+ */
+class Jre9Compat extends JreCompat {
+
+    private static final Method canAccessMethod;
+    private static final Method getModuleMethod;
+    private static final Method isExportedMethod;
+
+    static {
+        Method m1 = null;
+        Method m2 = null;
+        Method m3 = null;
+
+        try {
+            m1 = AccessibleObject.class.getMethod("canAccess", Object.class);
+            m2 = Class.class.getMethod("getModule");
+            Class<?> moduleClass = Class.forName("java.lang.Module");
+            m3 = moduleClass.getMethod("isExported", String.class);
+        } catch (NoSuchMethodException e) {
+            // Expected for Java 8
+        } catch (ClassNotFoundException e) {
+            // Can't log this so...
+            throw new RuntimeException(e);
+        }
+
+        canAccessMethod = m1;
+        getModuleMethod = m2;
+        isExportedMethod = m3;
+    }
+
+
+    public static boolean isSupported() {
+        return canAccessMethod != null;
+    }
+
+
+    @Override
+    public boolean canAcccess(Object base, AccessibleObject accessibleObject) {
+        try {
+            return ((Boolean) canAccessMethod.invoke(accessibleObject, base)).booleanValue();
+        } catch (ReflectiveOperationException | IllegalArgumentException e) {
+            return false;
+        }
+    }
+
+
+    @Override
+    public boolean isExported(Class<?> type) {
+        try {
+            String packageName = type.getPackage().getName();
+            Object module = getModuleMethod.invoke(type);
+            return ((Boolean) isExportedMethod.invoke(module, packageName)).booleanValue();
+        } catch (ReflectiveOperationException e) {
+            return false;
+        }
+    }
+}