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1: /* JarURLConnection.java -- Class for manipulating remote jar files 2: Copyright (C) 1998, 2002, 2003, 2005 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.Manifest; 46: 47: 48: /** 49: * This abstract class represents a common superclass for implementations 50: * of jar URL's. A jar URL is a special type of URL that allows JAR 51: * files on remote systems to be accessed. It has the form: 52: * <p> 53: * jar:<standard URL pointing to jar filei>!/file/within/jarfile 54: * <p> for example: 55: * <p> 56: * jar:http://www.urbanophile.com/java/foo.jar!/com/urbanophile/bar.class 57: * <p> 58: * That example URL points to the file /com/urbanophile/bar.class in the 59: * remote JAR file http://www.urbanophile.com/java/foo.jar. The HTTP 60: * protocol is used only as an example. Any supported remote protocol 61: * can be used. 62: * <p> 63: * This class currently works by retrieving the entire jar file into a 64: * local cache file, then performing standard jar operations on it. 65: * (At least this is true for the default protocol implementation). 66: * 67: * @author Aaron M. Renn (arenn@urbanophile.com) 68: * @author Kresten Krab Thorup (krab@gnu.org) 69: * @date Aug 10, 1999. 70: * 71: * @since 1.2 72: */ 73: public abstract class JarURLConnection extends URLConnection 74: { 75: /** 76: * This is the actual URL that points the remote jar file. This is parsed 77: * out of the jar URL by the constructor. 78: */ 79: private final URL jarFileURL; 80: 81: /** 82: * The connection to the jar file itself. A JarURLConnection 83: * can represent an entry in a jar file or an entire jar file. In 84: * either case this describes just the jar file itself. 85: */ 86: protected URLConnection jarFileURLConnection; 87: 88: /** 89: * This is the jar file "entry name" or portion after the "!/" in the 90: * URL which represents the pathname inside the actual jar file. 91: */ 92: private final String entryName; 93: 94: /** 95: * Creates a JarURLConnection from an URL object 96: * 97: * @param url The URL object for this connection. 98: * 99: * @exception MalformedURLException If url is invalid 100: * 101: * @specnote This constructor is protected since JDK 1.4 102: */ 103: protected JarURLConnection(URL url) throws MalformedURLException 104: { 105: super(url); 106: 107: if (! url.getProtocol().equals("jar")) 108: throw new MalformedURLException(url + ": Not jar protocol."); 109: 110: String spec = url.getFile(); 111: int bang = spec.indexOf("!/"); 112: if (bang == -1) 113: throw new MalformedURLException(url + ": No `!/' in spec."); 114: 115: // Extract the url for the jar itself. 116: jarFileURL = new URL(spec.substring(0, bang)); 117: 118: // Get the name of the entry, if any. 119: entryName = spec.length() == (bang + 2) ? null : spec.substring(bang + 2); 120: } 121: 122: /** 123: * This method returns the "real" URL where the JarFile is located. 124: * //****Is this right?***** 125: * 126: * @return The remote URL 127: */ 128: public URL getJarFileURL() 129: { 130: return jarFileURL; 131: } 132: 133: /** 134: * Returns the "entry name" portion of the jar URL. This is the portion 135: * after the "!/" in the jar URL that represents the pathname inside the 136: * actual jar file. 137: * 138: * @return The entry name. 139: */ 140: public String getEntryName() 141: { 142: return entryName; 143: } 144: 145: /** 146: * Returns the entry in this jar file specified by the URL. 147: * 148: * @return The jar entry 149: * 150: * @exception IOException If an error occurs 151: */ 152: public JarEntry getJarEntry() throws IOException 153: { 154: if (entryName == null) 155: return null; 156: JarFile jarFile = getJarFile(); 157: return jarFile != null ? jarFile.getJarEntry(entryName) : null; 158: } 159: 160: /** 161: * Returns a read-only JarFile object for the remote jar file 162: * 163: * @return The JarFile object 164: * 165: * @exception IOException If an error occurs 166: */ 167: public abstract JarFile getJarFile() throws IOException; 168: 169: /** 170: * Returns an array of Certificate objects for the jar file entry specified 171: * by this URL or null if there are none 172: * 173: * @return A Certificate array 174: * 175: * @exception IOException If an error occurs 176: */ 177: public Certificate[] getCertificates() throws IOException 178: { 179: JarEntry entry = getJarEntry(); 180: 181: return entry != null ? entry.getCertificates() : null; 182: } 183: 184: /** 185: * Returns the main Attributes for the jar file specified in the URL or 186: * null if there are none 187: * 188: * @return The main Attributes for the JAR file for this connection 189: * 190: * @exception IOException If an error occurs 191: */ 192: public Attributes getMainAttributes() throws IOException 193: { 194: Manifest manifest = getManifest(); 195: 196: return manifest != null ? manifest.getMainAttributes() : null; 197: } 198: 199: /** 200: * Returns the Attributes for the Jar entry specified by the URL or null 201: * if none 202: * 203: * @return The Attributes object for this connection if the URL for it points 204: * to a JAR file entry, null otherwise 205: * 206: * @exception IOException If an error occurs 207: */ 208: public Attributes getAttributes() throws IOException 209: { 210: JarEntry entry = getJarEntry(); 211: 212: return entry != null ? entry.getAttributes() : null; 213: } 214: 215: /** 216: * Returns a Manifest object for this jar file, or null if there is no 217: * manifest. 218: * 219: * @return The Manifest for this connection, or null if none 220: * 221: * @exception IOException If an error occurs 222: */ 223: public Manifest getManifest() throws IOException 224: { 225: JarFile file = getJarFile(); 226: 227: return file != null ? file.getManifest() : null; 228: } 229: }