001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.net;
019
020import java.io.IOException;
021import java.net.InetAddress;
022import java.net.InetSocketAddress;
023import java.net.Socket;
024import java.net.UnknownHostException;
025import java.nio.channels.SocketChannel;
026
027import javax.net.SocketFactory;
028
029import org.apache.hadoop.classification.InterfaceAudience;
030import org.apache.hadoop.classification.InterfaceStability;
031
032/**
033 * Specialized SocketFactory to create sockets with a SOCKS proxy
034 */
035@InterfaceAudience.Public
036@InterfaceStability.Evolving
037public class StandardSocketFactory extends SocketFactory {
038
039  /**
040   * Default empty constructor (for use with the reflection API).
041   */
042  public StandardSocketFactory() {
043  }
044
045  @Override
046  public Socket createSocket() throws IOException {
047    /*
048     * NOTE: This returns an NIO socket so that it has an associated 
049     * SocketChannel. As of now, this unfortunately makes streams returned
050     * by Socket.getInputStream() and Socket.getOutputStream() unusable
051     * (because a blocking read on input stream blocks write on output stream
052     * and vice versa).
053     * 
054     * So users of these socket factories should use 
055     * NetUtils.getInputStream(socket) and 
056     * NetUtils.getOutputStream(socket) instead.
057     * 
058     * A solution for hiding from this from user is to write a 
059     * 'FilterSocket' on the lines of FilterInputStream and extend it by
060     * overriding getInputStream() and getOutputStream().
061     */
062    return SocketChannel.open().socket();
063  }
064
065  @Override
066  public Socket createSocket(InetAddress addr, int port) throws IOException {
067
068    Socket socket = createSocket();
069    socket.connect(new InetSocketAddress(addr, port));
070    return socket;
071  }
072
073  @Override
074  public Socket createSocket(InetAddress addr, int port,
075      InetAddress localHostAddr, int localPort) throws IOException {
076
077    Socket socket = createSocket();
078    socket.bind(new InetSocketAddress(localHostAddr, localPort));
079    socket.connect(new InetSocketAddress(addr, port));
080    return socket;
081  }
082
083  @Override
084  public Socket createSocket(String host, int port) throws IOException,
085      UnknownHostException {
086
087    Socket socket = createSocket();
088    socket.connect(new InetSocketAddress(host, port));
089    return socket;
090  }
091
092  @Override
093  public Socket createSocket(String host, int port,
094      InetAddress localHostAddr, int localPort) throws IOException,
095      UnknownHostException {
096
097    Socket socket = createSocket();
098    socket.bind(new InetSocketAddress(localHostAddr, localPort));
099    socket.connect(new InetSocketAddress(host, port));
100    return socket;
101  }
102
103  @Override
104  public boolean equals(Object obj) {
105    if (this == obj)
106      return true;
107    if (obj == null)
108      return false;
109    return obj.getClass().equals(this.getClass());
110  }
111
112  @Override
113  public int hashCode() {
114    return this.getClass().hashCode();
115  }
116
117}