content: /*
   * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package java.net;
  
  import java.io.IOException;
  import java.util.jar.JarFile;
  import java.util.jar.JarEntry;
  import java.util.jar.Attributes;
  import java.util.jar.Manifest;
  import java.security.Permission;
  import sun.net.www.ParseUtil;
  
  /**
   * A URL Connection to a Java ARchive (JAR) file or an entry in a JAR
   * file.
   *
   * <p>The syntax of a JAR URL is:
   *
   * <pre>
   * jar:&lt;url&gt;!/{entry}
   * </pre>
   *
   * <p>for example:
   *
   * <p>{@code jar:http://www.foo.com/bar/baz.jar!/COM/foo/Quux.class}
   *
   * <p>Jar URLs should be used to refer to a JAR file or entries in
   * a JAR file. The example above is a JAR URL which refers to a JAR
   * entry. If the entry name is omitted, the URL refers to the whole
   * JAR file:
   *
   * {@code jar:http://www.foo.com/bar/baz.jar!/}
   *
   * <p>Users should cast the generic URLConnection to a
   * JarURLConnection when they know that the URL they created is a JAR
   * URL, and they need JAR-specific functionality. For example:
   *
   * <pre>
   * URL url = new URL("jar:file:/home/duke/duke.jar!/");
   * JarURLConnection jarConnection = (JarURLConnection)url.openConnection();
   * Manifest manifest = jarConnection.getManifest();
   * </pre>
   *
   * <p>JarURLConnection instances can only be used to read from JAR files.
   * It is not possible to get a {@link java.io.OutputStream} to modify or write
   * to the underlying JAR file using this class.
   * <p>Examples:
   *
   * <dl>
   *
   * <dt>A Jar entry
   * <dd>{@code jar:http://www.foo.com/bar/baz.jar!/COM/foo/Quux.class}
   *
   * <dt>A Jar file
   * <dd>{@code jar:http://www.foo.com/bar/baz.jar!/}
   *
   * <dt>A Jar directory
   * <dd>{@code jar:http://www.foo.com/bar/baz.jar!/COM/foo/}
   *
   * </dl>
   *
   * <p>{@code !/} is referred to as the <em>separator</em>.
   *
   * <p>When constructing a JAR url via {@code new URL(context, spec)},
   * the following rules apply:
   *
   * <ul>
   *
   * <li>if there is no context URL and the specification passed to the
   * URL constructor doesn't contain a separator, the URL is considered
   * to refer to a JarFile.
   *
   * <li>if there is a context URL, the context URL is assumed to refer
   * to a JAR file or a Jar directory.
   *
   * <li>if the specification begins with a '/', the Jar directory is
   * ignored, and the spec is considered to be at the root of the Jar
   * file.
   *
   * <p>Examples:
   *
   * <dl>
   *
   * <dt>context: <b>jar:http://www.foo.com/bar/jar.jar!/</b>,
   * spec:<b>baz/entry.txt</b>
   *
   * <dd>url:<b>jar:http://www.foo.com/bar/jar.jar!/baz/entry.txt</b>
   *
   * <dt>context: <b>jar:http://www.foo.com/bar/jar.jar!/baz</b>,
   * spec:<b>entry.txt</b>
   *
   * <dd>url:<b>jar:http://www.foo.com/bar/jar.jar!/baz/entry.txt</b>
   *
   * <dt>context: <b>jar:http://www.foo.com/bar/jar.jar!/baz</b>,
   * spec:<b>/entry.txt</b>
   *
   * <dd>url:<b>jar:http://www.foo.com/bar/jar.jar!/entry.txt</b>
   *
   * </dl>
   *
   * </ul>
   *
   * @see URL
   * @see URLConnection
   *
   * @see JarFile
   * @see java.util.jar.JarInputStream
   * @see Manifest
   * @see java.util.zip.ZipEntry
   *
   * @author Benjamin Renaud
   * @since 1.2
   */
  public abstract class JarURLConnection extends URLConnection {
  
      private URL jarFileURL;
      private String entryName;
  
      /**
       * The connection to the JAR file URL, if the connection has been
       * initiated. This should be set by connect.
       */
      protected URLConnection jarFileURLConnection;
  
      /**
       * Creates the new JarURLConnection to the specified URL.
       * @param url the URL
       * @throws MalformedURLException if no legal protocol
       * could be found in a specification string or the
       * string could not be parsed.
       */
  
      protected JarURLConnection(URL url) throws MalformedURLException {
          super(url);
          parseSpecs(url);
      }
  
      /* get the specs for a given url out of the cache, and compute and
       * cache them if they're not there.
       */
      private void parseSpecs(URL url) throws MalformedURLException {
          String spec = url.getFile();
  
          int separator = spec.indexOf("!/");
          /*
           * REMIND: we don't handle nested JAR URLs
           */
          if (separator == -1) {
              throw new MalformedURLException("no !/ found in url spec:" + spec);
          }
  
          jarFileURL = new URL(spec.substring(0, separator++));
          entryName = null;
  
          /* if ! is the last letter of the innerURL, entryName is null */
          if (++separator != spec.length()) {
              entryName = spec.substring(separator, spec.length());
              entryName = ParseUtil.decode (entryName);
          }
      }
  
      /**
       * Returns the URL for the Jar file for this connection.
       *
       * @return the URL for the Jar file for this connection.
       */
      public URL getJarFileURL() {
          return jarFileURL;
      }
  
      /**
       * Return the entry name for this connection. This method
       * returns null if the JAR file URL corresponding to this
       * connection points to a JAR file and not a JAR file entry.
       *
       * @return the entry name for this connection, if any.
       */
      public String getEntryName() {
          return entryName;
      }
  
      /**
       * Return the JAR file for this connection.
       *
       * @return the JAR file for this connection. If the connection is
       * a connection to an entry of a JAR file, the JAR file object is
       * returned
       *
       * @exception IOException if an IOException occurs while trying to
       * connect to the JAR file for this connection.
       *
       * @see #connect
       */
      public abstract JarFile getJarFile() throws IOException;
  
      /**
       * Returns the Manifest for this connection, or null if none.
       *
       * @return the manifest object corresponding to the JAR file object
       * for this connection.
       *
       * @exception IOException if getting the JAR file for this
       * connection causes an IOException to be thrown.
       *
       * @see #getJarFile
       */
      public Manifest getManifest() throws IOException {
          return getJarFile().getManifest();
      }
  
      /**
       * Return the JAR entry object for this connection, if any. This
       * method returns null if the JAR file URL corresponding to this
       * connection points to a JAR file and not a JAR file entry.
       *
       * @return the JAR entry object for this connection, or null if
       * the JAR URL for this connection points to a JAR file.
       *
       * @exception IOException if getting the JAR file for this
       * connection causes an IOException to be thrown.
       *
       * @see #getJarFile
       * @see #getJarEntry
       */
      public JarEntry getJarEntry() throws IOException {
          return getJarFile().getJarEntry(entryName);
      }
  
      /**
       * Return the Attributes object for this connection if the URL
       * for it points to a JAR file entry, null otherwise.
       *
       * @return the Attributes object for this connection if the URL
       * for it points to a JAR file entry, null otherwise.
       *
       * @exception IOException if getting the JAR entry causes an
       * IOException to be thrown.
       *
       * @see #getJarEntry
       */
      public Attributes getAttributes() throws IOException {
          JarEntry e = getJarEntry();
          return e != null ? e.getAttributes() : null;
      }
  
      /**
       * Returns the main Attributes for the JAR file for this
       * connection.
       *
       * @return the main Attributes for the JAR file for this
       * connection.
       *
       * @exception IOException if getting the manifest causes an
       * IOException to be thrown.
       *
       * @see #getJarFile
       * @see #getManifest
       */
      public Attributes getMainAttributes() throws IOException {
          Manifest man = getManifest();
          return man != null ? man.getMainAttributes() : null;
      }
  
      /**
       * Return the Certificate object for this connection if the URL
       * for it points to a JAR file entry, null otherwise. This method
       * can only be called once
       * the connection has been completely verified by reading
       * from the input stream until the end of the stream has been
       * reached. Otherwise, this method will return {@code null}
       *
       * @return the Certificate object for this connection if the URL
       * for it points to a JAR file entry, null otherwise.
       *
       * @exception IOException if getting the JAR entry causes an
       * IOException to be thrown.
       *
       * @see #getJarEntry
       */
      public java.security.cert.Certificate[] getCertificates()
           throws IOException
      {
          JarEntry e = getJarEntry();
          return e != null ? e.getCertificates() : null;
      }
  }
  