001 /* JarInputStream.java - InputStream for reading jar files
002 Copyright (C) 2000, 2004 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038 package java.util.jar;
039
040 import java.io.IOException;
041 import java.io.InputStream;
042 import java.util.zip.ZipEntry;
043 import java.util.zip.ZipInputStream;
044
045 /**
046 * InputStream for reading jar files.
047 * XXX - verification of the signatures in the Manifest file is not yet
048 * implemented.
049 *
050 * @since 1.2
051 * @author Mark Wielaard (mark@klomp.org)
052 */
053
054 public class JarInputStream extends ZipInputStream
055 {
056 // Fields
057
058 /** The manifest for this file or null when there was no manifest. */
059 private Manifest manifest;
060
061 /** The first real JarEntry for this file. Used by readManifest() to store
062 an entry that isn't the manifest but that should be returned by
063 getNextEntry next time it is called. Null when no firstEntry was read
064 while searching for the manifest entry, or when it has already been
065 returned by getNextEntry(). */
066 private JarEntry firstEntry;
067
068 // Constructors
069
070 /**
071 * Creates a new JarInputStream and tries to read the manifest.
072 * If such a manifest is present the JarInputStream tries to verify all
073 * the entry signatures while reading.
074 *
075 * @param in InputStream to read the jar from
076 * @exception IOException when an error occurs when opening or reading
077 */
078 public JarInputStream(InputStream in) throws IOException
079 {
080 this(in, true);
081 }
082
083 /**
084 * Creates a new JarInputStream and tries to read the manifest.
085 * If such a manifest is present and verify is true, the JarInputStream
086 * tries to verify all the entry signatures while reading.
087 *
088 * @param in InputStream to read the jar from
089 * @param verify whether or not to verify the manifest entries
090 * @exception IOException when an error occurs when opening or reading
091 */
092 public JarInputStream(InputStream in, boolean verify) throws IOException
093 {
094 super(in);
095 readManifest(verify);
096 }
097
098 // Methods
099
100 /**
101 * Set the manifest if found. Skips all entries that start with "META-INF/"
102 *
103 * @param verify when true (and a Manifest is found) checks the Manifest,
104 * when false no check is performed
105 * @exception IOException if an error occurs while reading
106 */
107 private void readManifest(boolean verify) throws IOException
108 {
109 firstEntry = (JarEntry) super.getNextEntry();
110 while ((firstEntry != null) &&
111 firstEntry.getName().startsWith("META-INF/"))
112 {
113 if (firstEntry.getName().equals(JarFile.MANIFEST_NAME))
114 {
115 manifest = new Manifest(this);
116 }
117 firstEntry = (JarEntry) super.getNextEntry();
118 }
119
120 if (verify)
121 {
122 // XXX
123 }
124 }
125
126 /**
127 * Creates a JarEntry for a particular name and consults the manifest
128 * for the Attributes of the entry.
129 * Used by <code>ZipEntry.getNextEntry()</code>
130 *
131 * @param name the name of the new entry
132 */
133 protected ZipEntry createZipEntry(String name)
134 {
135 ZipEntry zipEntry = super.createZipEntry(name);
136 JarEntry jarEntry = new JarEntry(zipEntry);
137 if (manifest != null)
138 {
139 jarEntry.attr = manifest.getAttributes(name);
140 }
141 return jarEntry;
142 }
143
144 /**
145 * Returns the Manifest for the jar file or null if there was no Manifest.
146 */
147 public Manifest getManifest()
148 {
149 return manifest;
150 }
151
152 /**
153 * Returns the next entry or null when there are no more entries.
154 * Does actually return a JarEntry, if you don't want to cast it yourself
155 * use <code>getNextJarEntry()</code>. Does not return any entries found
156 * at the beginning of the ZipFile that are special
157 * (those that start with "META-INF/").
158 *
159 * @exception IOException if an IO error occurs when reading the entry
160 */
161 public ZipEntry getNextEntry() throws IOException
162 {
163 ZipEntry entry;
164 if (firstEntry != null)
165 {
166 entry = firstEntry;
167 firstEntry = null;
168 }
169 else
170 {
171 entry = super.getNextEntry();
172 }
173 return entry;
174 }
175
176 /**
177 * Returns the next jar entry or null when there are no more entries.
178 *
179 * @exception IOException if an IO error occurs when reading the entry
180 */
181 public JarEntry getNextJarEntry() throws IOException
182 {
183 return (JarEntry) getNextEntry();
184 }
185
186 /**
187 * XXX
188 *
189 * @param buf XXX
190 * @param off XXX
191 * @param len XXX
192 * @return XXX
193 * @exception IOException XXX
194 */
195 public int read(byte[]buf, int off, int len) throws IOException
196 {
197 // XXX if (verify) {}
198 return super.read(buf, off, len);
199 }
200 }