1/*
2 * Copyright (C) 2010 Google Inc.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.google.doclava;
18
19import java.io.File;
20import java.io.FileOutputStream;
21import java.io.IOException;
22import java.io.InputStream;
23import java.net.URL;
24import java.util.Enumeration;
25import java.util.jar.JarEntry;
26import java.util.jar.JarFile;
27
28public class JarUtils {
29  /**
30   * Returns the jar file used to load class clazz, or defaultJar if clazz was not loaded from a
31   * jar.
32   */
33  public static JarFile jarForClass(Class<?> clazz, JarFile defaultJar) {
34    String path = "/" + clazz.getName().replace('.', '/') + ".class";
35    URL jarUrl = clazz.getResource(path);
36    if (jarUrl == null) {
37      return defaultJar;
38    }
39
40    String url = jarUrl.toString();
41    int bang = url.indexOf("!");
42    String JAR_URI_PREFIX = "jar:file:";
43    if (url.startsWith(JAR_URI_PREFIX) && bang != -1) {
44      try {
45        return new JarFile(url.substring(JAR_URI_PREFIX.length(), bang));
46      } catch (IOException e) {
47        throw new IllegalStateException("Error loading jar file.", e);
48      }
49    } else {
50      return defaultJar;
51    }
52  }
53
54  /**
55   * Copies a directory from a jar file to an external directory.
56   */
57  public static void copyResourcesToDirectory(JarFile fromJar, String jarDir, String destDir)
58      throws IOException {
59    for (Enumeration<JarEntry> entries = fromJar.entries(); entries.hasMoreElements();) {
60      JarEntry entry = entries.nextElement();
61      if (entry.getName().startsWith(jarDir + "/") && !entry.isDirectory()) {
62        File dest = new File(destDir + "/" + entry.getName().substring(jarDir.length() + 1));
63        File parent = dest.getParentFile();
64        if (parent != null) {
65          parent.mkdirs();
66        }
67
68        FileOutputStream out = new FileOutputStream(dest);
69        InputStream in = fromJar.getInputStream(entry);
70
71        try {
72          byte[] buffer = new byte[8 * 1024];
73
74          int s = 0;
75          while ((s = in.read(buffer)) > 0) {
76            out.write(buffer, 0, s);
77          }
78        } catch (IOException e) {
79          throw new IOException("Could not copy asset from jar file", e);
80        } finally {
81          try {
82            in.close();
83          } catch (IOException ignored) {}
84          try {
85            out.close();
86          } catch (IOException ignored) {}
87        }
88      }
89    }
90
91  }
92
93  private JarUtils() {} // non-instantiable
94}
95