bundleurlstreamhandler.java

来自「OSGI这是一个中间件,与UPNP齐名,是用于移植到嵌入式平台之上」· Java 代码 · 共 193 行

/*
 * Copyright (c) 2003-2004, KNOPFLERFISH project
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials
 *   provided with the distribution.
 *
 * - Neither the name of the KNOPFLERFISH project nor the names of its
 *   contributors may be used to endorse or promote products derived
 *   from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.knopflerfish.framework;

import java.io.*;
import java.net.*;
import java.security.*;

import java.util.Set;
import java.util.Dictionary;
import java.util.List;
import java.util.ArrayList;
import java.util.Map;
import java.util.HashSet;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Enumeration;
import java.util.Vector;

import java.util.jar.*;
import java.util.zip.*;

/**
 * Bundle URL handling.
 *
 * @author Jan Stein
 */
public class BundleURLStreamHandler extends URLStreamHandler {

  final public static String PROTOCOL = "bundle";

  private Bundles bundles;

  BundleURLStreamHandler(Bundles b) {
    bundles = b;
  }

  public URLConnection openConnection(URL u) {
    return new BundleURLConnection(u);
  }

  class BundleURLConnection extends URLConnection {
    private InputStream is = null;

    BundleURLConnection(URL u) {
      super(u);
    }

    public void connect() throws IOException {
      if (!connected) {
	BundleImpl b = null;
	try {
	  b = bundles.getBundle(Long.parseLong(url.getHost()));
	} catch (NumberFormatException ignore) { }
	if (b != null) {
	  BundleArchive a = b.getBundleArchive();
	  if (a != null) {
	    is = a.getInputStream(url.getFile(), url.getPort());
	  }
	}
	if (is != null) {
	  connected = true;
	} else {
	  throw new IOException("URL not found");
	}
      }
    }

    public InputStream getInputStream() {
      try {
	connect();
      } catch (IOException ignore) { }
      return is;
    }
  }

  /**
   * Equals calculation for bundle URLs.
   * @return <tt>true</tt> if the two urls are 
   * considered equal, ie. they refer to the same 
   * fragment in the same file.
   *
   * NYI! a complete check!
   */
  protected boolean equals(URL u1, URL u2) {
    String ref1 = u1.getRef();
    String ref2 = u2.getRef();
    return sameFile(u1, u2) && 
      (ref1 == ref2 ||
       (ref1 != null && ref1.equals(ref2)));
  }

  /**
   * Provides the hash calculation
   * @return an <tt>int</tt> suitable for hash table indexing
   */
  protected int hashCode(URL u) {
    int h = 0;

    if (PROTOCOL.equals(u.getProtocol())) {
      String host = u.getHost();
      if (host != null)
	h = host.hashCode();

      String file = u.getFile();
      if (file != null)
	h += file.hashCode();

      String ref = u.getRef();
      if (ref != null)
	h += ref.hashCode();

    } else {
      h = u.hashCode();
    }
    return h;
  }

  /**
   * Compare two urls to see whether they refer to the same file,
   * i.e., having the same protocol, host, port, and path.
   * @return true if u1 and u2 refer to the same file
   */
  protected boolean sameFile(URL u1, URL u2) {
    String p1 = u1.getProtocol();
    if (PROTOCOL.equals(p1)) {
      if (!p1.equals(u2.getProtocol()))
	return false;

      if (!hostsEqual(u1, u2))
	return false;

      if (!(u1.getFile() == u2.getFile() ||
	    (u1.getFile() != null && u1.getFile().equals(u2.getFile()))))
	return false;

      if (u1.getPort() != u2.getPort())
	return false;

      return true;
    } else {
      return u1.equals(u2);
    }
  }


  /**
   * Compares the host components of two URLs.
   * @param u1 the URL of the first host to compare 
   * @param u2 the URL of the second host to compare 
   * @return	<tt>true</tt> if and only if they 
   * are equal, <tt>false</tt> otherwise.
   */
  protected boolean hostsEqual(URL u1, URL u2) {
    String s1 = u1.getHost();
    String s2 = u2.getHost();
    return (s1 == s2) || (s1 != null && s1.equals(s2));
  }
  
}