Richard S. Hall | 930fecc | 2005-08-16 18:33:34 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2005 The Apache Software Foundation |
| 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 | */ |
Richard S. Hall | 5a03159 | 2005-08-19 19:53:58 +0000 | [diff] [blame^] | 17 | package org.apache.felix.moduleloader; |
Richard S. Hall | 930fecc | 2005-08-16 18:33:34 +0000 | [diff] [blame] | 18 | |
| 19 | import java.io.*; |
| 20 | import java.util.jar.JarFile; |
| 21 | import java.util.zip.ZipEntry; |
| 22 | |
| 23 | /** |
| 24 | * <p> |
| 25 | * This class implements a <tt>ResourceSource</tt> for retrieving resources |
| 26 | * from a JAR file. The approach used by this implementation is to defer |
| 27 | * opening the JAR file until a request for a resource is made. |
| 28 | * </p> |
Richard S. Hall | 5a03159 | 2005-08-19 19:53:58 +0000 | [diff] [blame^] | 29 | * @see org.apache.felix.moduleloader.ResourceSource |
Richard S. Hall | 930fecc | 2005-08-16 18:33:34 +0000 | [diff] [blame] | 30 | **/ |
| 31 | public class JarResourceSource implements ResourceSource |
| 32 | { |
| 33 | private static final int BUFSIZE = 4096; |
| 34 | |
| 35 | private File m_file = null; |
| 36 | private JarFile m_jarFile = null; |
| 37 | private boolean m_opened = false; |
| 38 | |
| 39 | /** |
| 40 | * <p> |
| 41 | * Constructs an instance using the specified file name as the source |
| 42 | * of the JAR file. |
| 43 | * </p> |
| 44 | * @param fileName the name of the JAR file to be used as the source. |
| 45 | **/ |
| 46 | public JarResourceSource(String fileName) |
| 47 | { |
| 48 | m_file = new File(fileName); |
| 49 | } |
| 50 | |
| 51 | /** |
| 52 | * <p> |
| 53 | * Constructs an instance using the specified file as the source |
| 54 | * of the JAR file. |
| 55 | * </p> |
| 56 | * @param file the JAR file to be used as the source. |
| 57 | **/ |
| 58 | public JarResourceSource(File file) |
| 59 | { |
| 60 | m_file = file; |
| 61 | } |
| 62 | |
| 63 | /** |
| 64 | * <p> |
| 65 | * Closes the JAR file if it has not already been closed. |
| 66 | * <p> |
| 67 | **/ |
| 68 | protected void finalize() |
| 69 | { |
| 70 | if (m_jarFile != null) |
| 71 | { |
| 72 | try { |
| 73 | m_jarFile.close(); |
| 74 | } catch (IOException ex) { |
| 75 | // Not much we can do, so ignore it. |
| 76 | } |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | /** |
| 81 | * <p> |
| 82 | * This method initializes the resource source. Since opening |
| 83 | * the JAR file is deferred until a request for a resource is |
| 84 | * actually made, this method really only sets a flag indicating |
| 85 | * that the resource source has been initialized. |
| 86 | * <p> |
| 87 | **/ |
| 88 | public void open() |
| 89 | { |
| 90 | m_opened = true; |
| 91 | } |
| 92 | |
| 93 | /** |
| 94 | * <p> |
| 95 | * This method deinitializes the resource source by closing |
| 96 | * the associated JAR file if it is open. |
| 97 | * <p> |
| 98 | **/ |
| 99 | public synchronized void close() |
| 100 | { |
| 101 | try { |
| 102 | if (m_jarFile != null) |
| 103 | { |
| 104 | m_jarFile.close(); |
| 105 | } |
| 106 | } catch (Exception ex) { |
| 107 | System.err.println("JarResourceSource: " + ex); |
| 108 | } |
| 109 | |
| 110 | m_jarFile = null; |
| 111 | m_opened = false; |
| 112 | } |
| 113 | |
| 114 | // JavaDoc comments are copied from ResourceSource. |
| 115 | public synchronized boolean hasResource(String name) throws IllegalStateException |
| 116 | { |
| 117 | if (!m_opened) |
| 118 | { |
| 119 | throw new IllegalStateException("JarResourceSource is not open"); |
| 120 | } |
| 121 | |
| 122 | // Open JAR file if not already opened. |
| 123 | if (m_jarFile == null) |
| 124 | { |
| 125 | try { |
| 126 | openJarFile(); |
| 127 | } catch (IOException ex) { |
| 128 | System.err.println("JarResourceSource: " + ex); |
| 129 | return false; |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | try { |
| 134 | ZipEntry ze = m_jarFile.getEntry(name); |
| 135 | return ze != null; |
| 136 | } catch (Exception ex) { |
| 137 | return false; |
| 138 | } finally { |
| 139 | } |
| 140 | } |
| 141 | |
| 142 | // JavaDoc comments are copied from ResourceSource. |
| 143 | public synchronized byte[] getBytes(String name) throws IllegalStateException |
| 144 | { |
| 145 | if (!m_opened) |
| 146 | { |
| 147 | throw new IllegalStateException("JarResourceSource is not open"); |
| 148 | } |
| 149 | |
| 150 | // Open JAR file if not already opened. |
| 151 | if (m_jarFile == null) |
| 152 | { |
| 153 | try { |
| 154 | openJarFile(); |
| 155 | } catch (IOException ex) { |
| 156 | System.err.println("JarResourceSource: " + ex); |
| 157 | return null; |
| 158 | } |
| 159 | } |
| 160 | |
| 161 | // Get the embedded resource. |
| 162 | InputStream is = null; |
| 163 | ByteArrayOutputStream baos = null; |
| 164 | |
| 165 | try { |
| 166 | ZipEntry ze = m_jarFile.getEntry(name); |
| 167 | if (ze == null) |
| 168 | { |
| 169 | return null; |
| 170 | } |
| 171 | is = m_jarFile.getInputStream(ze); |
| 172 | if (is == null) |
| 173 | { |
| 174 | return null; |
| 175 | } |
| 176 | baos = new ByteArrayOutputStream(BUFSIZE); |
| 177 | byte[] buf = new byte[BUFSIZE]; |
| 178 | int n = 0; |
| 179 | while ((n = is.read(buf, 0, buf.length)) >= 0) |
| 180 | { |
| 181 | baos.write(buf, 0, n); |
| 182 | } |
| 183 | return baos.toByteArray(); |
| 184 | |
| 185 | } catch (Exception ex) { |
| 186 | return null; |
| 187 | } finally { |
| 188 | try { |
| 189 | if (baos != null) baos.close(); |
| 190 | } catch (Exception ex) { |
| 191 | } |
| 192 | try { |
| 193 | if (is != null) is.close(); |
| 194 | } catch (Exception ex) { |
| 195 | } |
| 196 | } |
| 197 | } |
| 198 | |
| 199 | private void openJarFile() throws IOException |
| 200 | { |
| 201 | if (m_jarFile == null) |
| 202 | { |
| 203 | m_jarFile = new JarFile(m_file); |
| 204 | } |
| 205 | } |
| 206 | |
| 207 | public String toString() |
| 208 | { |
| 209 | return "JAR " + m_file.getPath(); |
| 210 | } |
| 211 | } |