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  /* @inheritDoc */
046  @Override
047  public Socket createSocket() throws IOException {
048    /*
049     * NOTE: This returns an NIO socket so that it has an associated 
050     * SocketChannel. As of now, this unfortunately makes streams returned
051     * by Socket.getInputStream() and Socket.getOutputStream() unusable
052     * (because a blocking read on input stream blocks write on output stream
053     * and vice versa).
054     * 
055     * So users of these socket factories should use 
056     * NetUtils.getInputStream(socket) and 
057     * NetUtils.getOutputStream(socket) instead.
058     * 
059     * A solution for hiding from this from user is to write a 
060     * 'FilterSocket' on the lines of FilterInputStream and extend it by
061     * overriding getInputStream() and getOutputStream().
062     */
063    return SocketChannel.open().socket();
064  }
065
066  /* @inheritDoc */
067  @Override
068  public Socket createSocket(InetAddress addr, int port) throws IOException {
069
070    Socket socket = createSocket();
071    socket.connect(new InetSocketAddress(addr, port));
072    return socket;
073  }
074
075  /* @inheritDoc */
076  @Override
077  public Socket createSocket(InetAddress addr, int port,
078      InetAddress localHostAddr, int localPort) throws IOException {
079
080    Socket socket = createSocket();
081    socket.bind(new InetSocketAddress(localHostAddr, localPort));
082    socket.connect(new InetSocketAddress(addr, port));
083    return socket;
084  }
085
086  /* @inheritDoc */
087  @Override
088  public Socket createSocket(String host, int port) throws IOException,
089      UnknownHostException {
090
091    Socket socket = createSocket();
092    socket.connect(new InetSocketAddress(host, port));
093    return socket;
094  }
095
096  /* @inheritDoc */
097  @Override
098  public Socket createSocket(String host, int port,
099      InetAddress localHostAddr, int localPort) throws IOException,
100      UnknownHostException {
101
102    Socket socket = createSocket();
103    socket.bind(new InetSocketAddress(localHostAddr, localPort));
104    socket.connect(new InetSocketAddress(host, port));
105    return socket;
106  }
107
108  /* @inheritDoc */
109  @Override
110  public boolean equals(Object obj) {
111    if (this == obj)
112      return true;
113    if (obj == null)
114      return false;
115    return obj.getClass().equals(this.getClass());
116  }
117
118  /* @inheritDoc */
119  @Override
120  public int hashCode() {
121    return this.getClass().hashCode();
122  }
123
124}