1 /*
   2  * Copyright (c) 1997, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.net;
  27 
  28 import java.io.IOException;
  29 import java.util.jar.JarFile;
  30 import java.util.jar.JarEntry;
  31 import java.util.jar.Attributes;
  32 import java.util.jar.Manifest;
  33 import java.security.Permission;
  34 import sun.net.www.ParseUtil;
  35 
  36 /**
  37  * A URL Connection to a Java ARchive (JAR) file or an entry in a JAR
  38  * file.
  39  *
  40  * <p>The syntax of a JAR URL is:
  41  *
  42  * <pre>
  43  * jar:&lt;url&gt;!/{entry}
  44  * </pre>
  45  *
  46  * <p>for example:
  47  *
  48  * <p>{@code jar:http://www.foo.com/bar/baz.jar!/COM/foo/Quux.class}
  49  *
  50  * <p>Jar URLs should be used to refer to a JAR file or entries in
  51  * a JAR file. The example above is a JAR URL which refers to a JAR
  52  * entry. If the entry name is omitted, the URL refers to the whole
  53  * JAR file:
  54  *
  55  * {@code jar:http://www.foo.com/bar/baz.jar!/}
  56  *
  57  * <p>Users should cast the generic URLConnection to a
  58  * JarURLConnection when they know that the URL they created is a JAR
  59  * URL, and they need JAR-specific functionality. For example:
  60  *
  61  * <pre>
  62  * URL url = new URL("jar:file:/home/duke/duke.jar!/");
  63  * JarURLConnection jarConnection = (JarURLConnection)url.openConnection();
  64  * Manifest manifest = jarConnection.getManifest();
  65  * </pre>
  66  *
  67  * <p>JarURLConnection instances can only be used to read from JAR files.
  68  * It is not possible to get a {@link java.io.OutputStream} to modify or write
  69  * to the underlying JAR file using this class.
  70  * <p>Examples:
  71  *
  72  * <dl>
  73  *
  74  * <dt>A Jar entry
  75  * <dd>{@code jar:http://www.foo.com/bar/baz.jar!/COM/foo/Quux.class}
  76  *
  77  * <dt>A Jar file
  78  * <dd>{@code jar:http://www.foo.com/bar/baz.jar!/}
  79  *
  80  * <dt>A Jar directory
  81  * <dd>{@code jar:http://www.foo.com/bar/baz.jar!/COM/foo/}
  82  *
  83  * </dl>
  84  *
  85  * <p>{@code !/} is referred to as the <em>separator</em>.
  86  *
  87  * <p>When constructing a JAR url via {@code new URL(context, spec)},
  88  * the following rules apply:
  89  *
  90  * <ul>
  91  *
  92  * <li>if there is no context URL and the specification passed to the
  93  * URL constructor doesn't contain a separator, the URL is considered
  94  * to refer to a JarFile.
  95  *
  96  * <li>if there is a context URL, the context URL is assumed to refer
  97  * to a JAR file or a Jar directory.
  98  *
  99  * <li>if the specification begins with a '/', the Jar directory is
 100  * ignored, and the spec is considered to be at the root of the Jar
 101  * file.
 102  *
 103  * <p>Examples:
 104  *
 105  * <dl>
 106  *
 107  * <dt>context: <b>jar:http://www.foo.com/bar/jar.jar!/</b>,
 108  * spec:<b>baz/entry.txt</b>
 109  *
 110  * <dd>url:<b>jar:http://www.foo.com/bar/jar.jar!/baz/entry.txt</b>
 111  *
 112  * <dt>context: <b>jar:http://www.foo.com/bar/jar.jar!/baz</b>,
 113  * spec:<b>entry.txt</b>
 114  *
 115  * <dd>url:<b>jar:http://www.foo.com/bar/jar.jar!/baz/entry.txt</b>
 116  *
 117  * <dt>context: <b>jar:http://www.foo.com/bar/jar.jar!/baz</b>,
 118  * spec:<b>/entry.txt</b>
 119  *
 120  * <dd>url:<b>jar:http://www.foo.com/bar/jar.jar!/entry.txt</b>
 121  *
 122  * </dl>
 123  *
 124  * </ul>
 125  *
 126  * @see java.net.URL
 127  * @see java.net.URLConnection
 128  *
 129  * @see java.util.jar.JarFile
 130  * @see java.util.jar.JarInputStream
 131  * @see java.util.jar.Manifest
 132  * @see java.util.zip.ZipEntry
 133  *
 134  * @author Benjamin Renaud
 135  * @since 1.2
 136  */
 137 public abstract class JarURLConnection extends URLConnection {
 138 
 139     private URL jarFileURL;
 140     private String entryName;
 141 
 142     /**
 143      * The connection to the JAR file URL, if the connection has been
 144      * initiated. This should be set by connect.
 145      */
 146     protected URLConnection jarFileURLConnection;
 147 
 148     /**
 149      * Creates the new JarURLConnection to the specified URL.
 150      * @param url the URL
 151      * @throws MalformedURLException if no legal protocol
 152      * could be found in a specification string or the
 153      * string could not be parsed.
 154      */
 155 
 156     protected JarURLConnection(URL url) throws MalformedURLException {
 157         super(url);
 158         parseSpecs(url);
 159     }
 160 
 161     /* get the specs for a given url out of the cache, and compute and
 162      * cache them if they're not there.
 163      */
 164     private void parseSpecs(URL url) throws MalformedURLException {
 165         String spec = url.getFile();
 166 
 167         int separator = spec.indexOf("!/");
 168         /*
 169          * REMIND: we don't handle nested JAR URLs
 170          */
 171         if (separator == -1) {
 172             throw new MalformedURLException("no !/ found in url spec:" + spec);
 173         }
 174 
 175         jarFileURL = new URL(spec.substring(0, separator++));
 176         /*
 177          * The url argument may have had a runtime fragment appended, so
 178          * we need to add a runtime fragment to the jarFileURL to enable
 179          * runtime versioning when the underlying jar file is opened.
 180          */
 181         if ("runtime".equals(url.getRef())) {
 182             jarFileURL = new URL(jarFileURL, "#runtime");
 183         }
 184         entryName = null;
 185 
 186         /* if ! is the last letter of the innerURL, entryName is null */
 187         if (++separator != spec.length()) {
 188             entryName = spec.substring(separator, spec.length());
 189             entryName = ParseUtil.decode (entryName);
 190         }
 191     }
 192 
 193     /**
 194      * Returns the URL for the Jar file for this connection.
 195      *
 196      * @return the URL for the Jar file for this connection.
 197      */
 198     public URL getJarFileURL() {
 199         return jarFileURL;
 200     }
 201 
 202     /**
 203      * Return the entry name for this connection. This method
 204      * returns null if the JAR file URL corresponding to this
 205      * connection points to a JAR file and not a JAR file entry.
 206      *
 207      * @return the entry name for this connection, if any.
 208      */
 209     public String getEntryName() {
 210         return entryName;
 211     }
 212 
 213     /**
 214      * Return the JAR file for this connection.
 215      *
 216      * @return the JAR file for this connection. If the connection is
 217      * a connection to an entry of a JAR file, the JAR file object is
 218      * returned
 219      *
 220      * @exception IOException if an IOException occurs while trying to
 221      * connect to the JAR file for this connection.
 222      *
 223      * @see #connect
 224      */
 225     public abstract JarFile getJarFile() throws IOException;
 226 
 227     /**
 228      * Returns the Manifest for this connection, or null if none.
 229      *
 230      * @return the manifest object corresponding to the JAR file object
 231      * for this connection.
 232      *
 233      * @exception IOException if getting the JAR file for this
 234      * connection causes an IOException to be thrown.
 235      *
 236      * @see #getJarFile
 237      */
 238     public Manifest getManifest() throws IOException {
 239         return getJarFile().getManifest();
 240     }
 241 
 242     /**
 243      * Return the JAR entry object for this connection, if any. This
 244      * method returns null if the JAR file URL corresponding to this
 245      * connection points to a JAR file and not a JAR file entry.
 246      *
 247      * @return the JAR entry object for this connection, or null if
 248      * the JAR URL for this connection points to a JAR file.
 249      *
 250      * @exception IOException if getting the JAR file for this
 251      * connection causes an IOException to be thrown.
 252      *
 253      * @see #getJarFile
 254      * @see #getJarEntry
 255      */
 256     public JarEntry getJarEntry() throws IOException {
 257         return entryName == null ? null : getJarFile().getJarEntry(entryName);
 258     }
 259 
 260     /**
 261      * Return the Attributes object for this connection if the URL
 262      * for it points to a JAR file entry, null otherwise.
 263      *
 264      * @return the Attributes object for this connection if the URL
 265      * for it points to a JAR file entry, null otherwise.
 266      *
 267      * @exception IOException if getting the JAR entry causes an
 268      * IOException to be thrown.
 269      *
 270      * @see #getJarEntry
 271      */
 272     public Attributes getAttributes() throws IOException {
 273         JarEntry e = getJarEntry();
 274         return e != null ? e.getAttributes() : null;
 275     }
 276 
 277     /**
 278      * Returns the main Attributes for the JAR file for this
 279      * connection.
 280      *
 281      * @return the main Attributes for the JAR file for this
 282      * connection.
 283      *
 284      * @exception IOException if getting the manifest causes an
 285      * IOException to be thrown.
 286      *
 287      * @see #getJarFile
 288      * @see #getManifest
 289      */
 290     public Attributes getMainAttributes() throws IOException {
 291         Manifest man = getManifest();
 292         return man != null ? man.getMainAttributes() : null;
 293     }
 294 
 295     /**
 296      * Returns the Certificate objects for this connection if the URL
 297      * for it points to a JAR file entry, null otherwise. This method
 298      * can only be called once
 299      * the connection has been completely verified by reading
 300      * from the input stream until the end of the stream has been
 301      * reached. Otherwise, this method will return {@code null}
 302      *
 303      * @return the Certificate object for this connection if the URL
 304      * for it points to a JAR file entry, null otherwise.
 305      *
 306      * @exception IOException if getting the JAR entry causes an
 307      * IOException to be thrown.
 308      *
 309      * @see #getJarEntry
 310      */
 311     public java.security.cert.Certificate[] getCertificates()
 312          throws IOException
 313     {
 314         JarEntry e = getJarEntry();
 315         return e != null ? e.getCertificates() : null;
 316     }
 317 }