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1: /* JarURLConnection.java -- Class for manipulating remote jar files 2: Copyright (C) 1998, 2002, 2003 Free Software Foundation, Inc. 3: 4: This file is part of GNU Classpath. 5: 6: GNU Classpath is free software; you can redistribute it and/or modify 7: it under the terms of the GNU General Public License as published by 8: the Free Software Foundation; either version 2, or (at your option) 9: any later version. 10: 11: GNU Classpath is distributed in the hope that it will be useful, but 12: WITHOUT ANY WARRANTY; without even the implied warranty of 13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14: General Public License for more details. 15: 16: You should have received a copy of the GNU General Public License 17: along with GNU Classpath; see the file COPYING. If not, write to the 18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 19: 02110-1301 USA. 20: 21: Linking this library statically or dynamically with other modules is 22: making a combined work based on this library. Thus, the terms and 23: conditions of the GNU General Public License cover the whole 24: combination. 25: 26: As a special exception, the copyright holders of this library give you 27: permission to link this library with independent modules to produce an 28: executable, regardless of the license terms of these independent 29: modules, and to copy and distribute the resulting executable under 30: terms of your choice, provided that you also meet, for each linked 31: independent module, the terms and conditions of the license of that 32: module. An independent module is a module which is not derived from 33: or based on this library. If you modify this library, you may extend 34: this exception to your version of the library, but you are not 35: obligated to do so. If you do not wish to do so, delete this 36: exception statement from your version. */ 37: 38: package java.net; 39: 40: import java.io.IOException; 41: import java.security.cert.Certificate; 42: import java.util.jar.Attributes; 43: import java.util.jar.JarEntry; 44: import java.util.jar.JarFile; 45: import java.util.jar.JarInputStream; 46: import java.util.jar.Manifest; 47: import java.util.zip.ZipEntry; 48: 49: 50: /** 51: * This abstract class represents a common superclass for implementations 52: * of jar URL's. A jar URL is a special type of URL that allows JAR 53: * files on remote systems to be accessed. It has the form: 54: * <p> 55: * jar:<standard URL pointing to jar filei>!/file/within/jarfile 56: * <p> for example: 57: * <p> 58: * jar:http://www.urbanophile.com/java/foo.jar!/com/urbanophile/bar.class 59: * <p> 60: * That example URL points to the file /com/urbanophile/bar.class in the 61: * remote JAR file http://www.urbanophile.com/java/foo.jar. The HTTP 62: * protocol is used only as an example. Any supported remote protocol 63: * can be used. 64: * <p> 65: * This class currently works by retrieving the entire jar file into a 66: * local cache file, then performing standard jar operations on it. 67: * (At least this is true for the default protocol implementation). 68: * 69: * @author Aaron M. Renn (arenn@urbanophile.com) 70: * @author Kresten Krab Thorup (krab@gnu.org) 71: * @date Aug 10, 1999. 72: * 73: * @since 1.2 74: */ 75: public abstract class JarURLConnection extends URLConnection 76: { 77: /** 78: * This is the actual URL that points the remote jar file. This is parsed 79: * out of the jar URL by the constructor. 80: */ 81: private final URL jarFileURL; 82: 83: /** 84: * The connection to the jar file itself. A JarURLConnection 85: * can represent an entry in a jar file or an entire jar file. In 86: * either case this describes just the jar file itself. 87: */ 88: protected URLConnection jarFileURLConnection; 89: 90: /** 91: * This is the jar file "entry name" or portion after the "!/" in the 92: * URL which represents the pathname inside the actual jar file. 93: */ 94: private final String entryName; 95: 96: /** 97: * Creates a JarURLConnection from an URL object 98: * 99: * @param url The URL object for this connection. 100: * 101: * @exception MalformedURLException If url is invalid 102: * 103: * @specnote This constructor is protected since JDK 1.4 104: */ 105: protected JarURLConnection(URL url) throws MalformedURLException 106: { 107: super(url); 108: 109: if (! url.getProtocol().equals("jar")) 110: throw new MalformedURLException(url + ": Not jar protocol."); 111: 112: String spec = url.getFile(); 113: int bang = spec.indexOf("!/"); 114: if (bang == -1) 115: throw new MalformedURLException(url + ": No `!/' in spec."); 116: 117: // Extract the url for the jar itself. 118: jarFileURL = new URL(spec.substring(0, bang)); 119: 120: // Get the name of the entry, if any. 121: entryName = spec.length() == (bang + 2) ? null : spec.substring(bang + 2); 122: } 123: 124: /** 125: * This method returns the "real" URL where the JarFile is located. 126: * //****Is this right?***** 127: * 128: * @return The remote URL 129: */ 130: public URL getJarFileURL() 131: { 132: return jarFileURL; 133: } 134: 135: /** 136: * Returns the "entry name" portion of the jar URL. This is the portion 137: * after the "!/" in the jar URL that represents the pathname inside the 138: * actual jar file. 139: * 140: * @return The entry name. 141: */ 142: public String getEntryName() 143: { 144: return entryName; 145: } 146: 147: /** 148: * Returns the entry in this jar file specified by the URL. 149: * 150: * @return The jar entry 151: * 152: * @exception IOException If an error occurs 153: */ 154: public JarEntry getJarEntry() throws IOException 155: { 156: JarFile jarfile = null; 157: 158: if (entryName == null) 159: return null; 160: 161: if (! doInput) 162: throw new ProtocolException("Can't open JarEntry if doInput is false"); 163: 164: try 165: { 166: jarfile = getJarFile (); 167: } 168: catch (IOException x) 169: { 170: /* ignore */ 171: } 172: 173: if (jarfile == null) 174: { 175: JarInputStream zis = new JarInputStream( 176: jarFileURLConnection.getInputStream ()); 177: 178: // This is hideous, we're doing a linear search for the thing... 179: for (ZipEntry ent = zis.getNextEntry (); 180: ent != null; 181: ent = zis.getNextEntry ()) 182: { 183: if (entryName.equals (ent.getName())) 184: { 185: return new JarEntry (ent); 186: } 187: } 188: } 189: 190: else 191: { 192: return jarfile.getJarEntry (entryName); 193: } 194: 195: return null; 196: } 197: 198: /** 199: * Returns a read-only JarFile object for the remote jar file 200: * 201: * @return The JarFile object 202: * 203: * @exception IOException If an error occurs 204: */ 205: public abstract JarFile getJarFile() throws IOException; 206: 207: /** 208: * Returns an array of Certificate objects for the jar file entry specified 209: * by this URL or null if there are none 210: * 211: * @return A Certificate array 212: * 213: * @exception IOException If an error occurs 214: */ 215: public Certificate[] getCertificates() throws IOException 216: { 217: JarEntry entry = getJarEntry(); 218: 219: return entry != null ? entry.getCertificates() : null; 220: } 221: 222: /** 223: * Returns the main Attributes for the jar file specified in the URL or 224: * null if there are none 225: * 226: * @return The main Attributes for the JAR file for this connection 227: * 228: * @exception IOException If an error occurs 229: */ 230: public Attributes getMainAttributes() throws IOException 231: { 232: Manifest manifest = getManifest(); 233: 234: return manifest != null ? manifest.getMainAttributes() : null; 235: } 236: 237: /** 238: * Returns the Attributes for the Jar entry specified by the URL or null 239: * if none 240: * 241: * @return The Attributes object for this connection if the URL for it points 242: * to a JAR file entry, null otherwise 243: * 244: * @exception IOException If an error occurs 245: */ 246: public Attributes getAttributes() throws IOException 247: { 248: JarEntry entry = getJarEntry(); 249: 250: return entry != null ? entry.getAttributes() : null; 251: } 252: 253: /** 254: * Returns a Manifest object for this jar file, or null if there is no 255: * manifest. 256: * 257: * @return The Manifest for this connection, or null if none 258: * 259: * @exception IOException If an error occurs 260: */ 261: public Manifest getManifest() throws IOException 262: { 263: JarFile file = getJarFile(); 264: 265: return file != null ? file.getManifest() : null; 266: } 267: }