Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.net; import java.io.IOException; import java.net.InetAddress; import java.net.InetSocketAddress; import java.net.Proxy; import java.net.ServerSocket; import java.net.Socket; import java.net.UnknownHostException; import javax.net.SocketFactory; /*** * DefaultSocketFactory implements the SocketFactory interface by * simply wrapping the java.net.Socket and java.net.ServerSocket * constructors. It is the default SocketFactory used by * {@link org.apache.commons.net.SocketClient} * implementations. * <p> * <p> * @see SocketFactory * @see SocketClient * @see SocketClient#setSocketFactory ***/ public class DefaultSocketFactory extends SocketFactory { /** The proxy to use when creating new sockets. */ private final Proxy connProxy; /** * The default constructor. */ public DefaultSocketFactory() { this(null); } /** * A constructor for sockets with proxy support. * * @param proxy The Proxy to use when creating new Sockets. * @since 3.2 */ public DefaultSocketFactory(Proxy proxy) { connProxy = proxy; } /** * Creates an unconnected Socket. * * @return A new unconnected Socket. * @exception IOException If an I/O error occurs while creating the Socket. * @since 3.2 */ @Override public Socket createSocket() throws IOException { if (connProxy != null) { return new Socket(connProxy); } return new Socket(); } /*** * Creates a Socket connected to the given host and port. * <p> * @param host The hostname to connect to. * @param port The port to connect to. * @return A Socket connected to the given host and port. * @exception UnknownHostException If the hostname cannot be resolved. * @exception IOException If an I/O error occurs while creating the Socket. ***/ @Override public Socket createSocket(String host, int port) throws UnknownHostException, IOException { if (connProxy != null) { Socket s = new Socket(connProxy); s.connect(new InetSocketAddress(host, port)); return s; } return new Socket(host, port); } /*** * Creates a Socket connected to the given host and port. * <p> * @param address The address of the host to connect to. * @param port The port to connect to. * @return A Socket connected to the given host and port. * @exception IOException If an I/O error occurs while creating the Socket. ***/ @Override public Socket createSocket(InetAddress address, int port) throws IOException { if (connProxy != null) { Socket s = new Socket(connProxy); s.connect(new InetSocketAddress(address, port)); return s; } return new Socket(address, port); } /*** * Creates a Socket connected to the given host and port and * originating from the specified local address and port. * <p> * @param host The hostname to connect to. * @param port The port to connect to. * @param localAddr The local address to use. * @param localPort The local port to use. * @return A Socket connected to the given host and port. * @exception UnknownHostException If the hostname cannot be resolved. * @exception IOException If an I/O error occurs while creating the Socket. ***/ @Override public Socket createSocket(String host, int port, InetAddress localAddr, int localPort) throws UnknownHostException, IOException { if (connProxy != null) { Socket s = new Socket(connProxy); s.bind(new InetSocketAddress(localAddr, localPort)); s.connect(new InetSocketAddress(host, port)); return s; } return new Socket(host, port, localAddr, localPort); } /*** * Creates a Socket connected to the given host and port and * originating from the specified local address and port. * <p> * @param address The address of the host to connect to. * @param port The port to connect to. * @param localAddr The local address to use. * @param localPort The local port to use. * @return A Socket connected to the given host and port. * @exception IOException If an I/O error occurs while creating the Socket. ***/ @Override public Socket createSocket(InetAddress address, int port, InetAddress localAddr, int localPort) throws IOException { if (connProxy != null) { Socket s = new Socket(connProxy); s.bind(new InetSocketAddress(localAddr, localPort)); s.connect(new InetSocketAddress(address, port)); return s; } return new Socket(address, port, localAddr, localPort); } /*** * Creates a ServerSocket bound to a specified port. A port * of 0 will create the ServerSocket on a system-determined free port. * <p> * @param port The port on which to listen, or 0 to use any free port. * @return A ServerSocket that will listen on a specified port. * @exception IOException If an I/O error occurs while creating * the ServerSocket. ***/ public ServerSocket createServerSocket(int port) throws IOException { return new ServerSocket(port); } /*** * Creates a ServerSocket bound to a specified port with a given * maximum queue length for incoming connections. A port of 0 will * create the ServerSocket on a system-determined free port. * <p> * @param port The port on which to listen, or 0 to use any free port. * @param backlog The maximum length of the queue for incoming connections. * @return A ServerSocket that will listen on a specified port. * @exception IOException If an I/O error occurs while creating * the ServerSocket. ***/ public ServerSocket createServerSocket(int port, int backlog) throws IOException { return new ServerSocket(port, backlog); } /*** * Creates a ServerSocket bound to a specified port on a given local * address with a given maximum queue length for incoming connections. * A port of 0 will * create the ServerSocket on a system-determined free port. * <p> * @param port The port on which to listen, or 0 to use any free port. * @param backlog The maximum length of the queue for incoming connections. * @param bindAddr The local address to which the ServerSocket should bind. * @return A ServerSocket that will listen on a specified port. * @exception IOException If an I/O error occurs while creating * the ServerSocket. ***/ public ServerSocket createServerSocket(int port, int backlog, InetAddress bindAddr) throws IOException { return new ServerSocket(port, backlog, bindAddr); } }