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java/org/apache/tomcat/util/scan/JarFileUrlJar.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 org.apache.tomcat.util.scan;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.JarURLConnection;
+import java.net.URISyntaxException;
+import java.net.URL;
+import java.util.Enumeration;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+import java.util.jar.Manifest;
+import java.util.zip.ZipEntry;
+
+import org.apache.tomcat.Jar;
+import org.apache.tomcat.util.compat.JreCompat;
+
+/**
+ * Implementation of {@link Jar} that is optimised for file based JAR URLs that
+ * refer directly to a JAR file (e.g URLs of the form jar:file: ... .jar!/ or
+ * file:... .jar).
+ */
+public class JarFileUrlJar implements Jar {
+
+    private final JarFile jarFile;
+    private final URL jarFileURL;
+    private final boolean multiRelease;
+    private Enumeration<JarEntry> entries;
+    private Set<String> entryNamesSeen;
+    private JarEntry entry = null;
+
+    public JarFileUrlJar(URL url, boolean startsWithJar) throws IOException {
+        if (startsWithJar) {
+            // jar:file:...
+            JarURLConnection jarConn = (JarURLConnection) url.openConnection();
+            jarConn.setUseCaches(false);
+            jarFile = jarConn.getJarFile();
+            jarFileURL = jarConn.getJarFileURL();
+        } else {
+            // file:...
+            File f;
+            try {
+                f = new File(url.toURI());
+            } catch (URISyntaxException e) {
+                throw new IOException(e);
+            }
+            jarFile = JreCompat.getInstance().jarFileNewInstance(f);
+            jarFileURL = url;
+        }
+        multiRelease = JreCompat.getInstance().jarFileIsMultiRelease(jarFile);
+    }
+
+
+    @Override
+    public URL getJarFileURL() {
+        return jarFileURL;
+    }
+
+
+    @Override
+    @Deprecated
+    public boolean entryExists(String name) {
+        return false;
+    }
+
+    @Override
+    public InputStream getInputStream(String name) throws IOException {
+        // JarFile#getEntry() is multi-release aware
+        ZipEntry entry = jarFile.getEntry(name);
+        if (entry == null) {
+            return null;
+        } else {
+            return jarFile.getInputStream(entry);
+        }
+    }
+
+    @Override
+    public long getLastModified(String name) throws IOException {
+        // JarFile#getEntry() is multi-release aware
+        ZipEntry entry = jarFile.getEntry(name);
+        if (entry == null) {
+            return -1;
+        } else {
+            return entry.getTime();
+        }
+    }
+
+    @Override
+    public boolean exists(String name) throws IOException {
+        // JarFile#getEntry() is multi-release aware
+        ZipEntry entry = jarFile.getEntry(name);
+        return entry != null;
+    }
+
+    @Override
+    public String getURL(String entry) {
+        StringBuilder result = new StringBuilder("jar:");
+        result.append(getJarFileURL().toExternalForm());
+        result.append("!/");
+        result.append(entry);
+
+        return result.toString();
+    }
+
+    @Override
+    public void close() {
+        if (jarFile != null) {
+            try {
+                jarFile.close();
+            } catch (IOException e) {
+                // Ignore
+            }
+        }
+    }
+
+    @Override
+    public void nextEntry() {
+        // JarFile#entries() is NOT multi-release aware
+        if (entries == null) {
+            entries = jarFile.entries();
+            if (multiRelease) {
+                entryNamesSeen = new HashSet<>();
+            }
+        }
+
+        if (multiRelease) {
+            // Need to ensure that:
+            // - the one, correct entry is returned where multiple versions
+            //   are available
+            // - that the order of entries in the JAR doesn't prevent the
+            //   correct entries being returned
+            // - the case where an entry appears in the versions location
+            //   but not in the the base location is handled correctly
+
+            // Enumerate the entries until one is reached that represents an
+            // entry that has not been seen before.
+            String name = null;
+            while (true) {
+                if (entries.hasMoreElements()) {
+                    entry = entries.nextElement();
+                    name = entry.getName();
+                    // Get 'base' name
+                    if (name.startsWith("META-INF/versions/")) {
+                        int i = name.indexOf('/', 18);
+                        if (i == -1) {
+                            continue;
+                        }
+                        name = name.substring(i + 1);
+                    }
+                    if (name.length() == 0 || entryNamesSeen.contains(name)) {
+                        continue;
+                    }
+
+                    entryNamesSeen.add(name);
+
+                    // JarFile.getJarEntry is version aware so use it
+                    entry = jarFile.getJarEntry(entry.getName());
+                    break;
+                } else {
+                    entry = null;
+                    break;
+                }
+            }
+        } else {
+            if (entries.hasMoreElements()) {
+                entry = entries.nextElement();
+            } else {
+                entry = null;
+            }
+        }
+    }
+
+    @Override
+    public String getEntryName() {
+        if (entry == null) {
+            return null;
+        } else {
+            return entry.getName();
+        }
+    }
+
+    @Override
+    public InputStream getEntryInputStream() throws IOException {
+        if (entry == null) {
+            return null;
+        } else {
+            return jarFile.getInputStream(entry);
+        }
+    }
+
+    @Override
+    public Manifest getManifest() throws IOException {
+        return jarFile.getManifest();
+    }
+
+
+    @Override
+    public void reset() throws IOException {
+        entries = null;
+        entryNamesSeen = null;
+        entry = null;
+    }
+}