Java Socket 文件传输3

Java Socket实战之七 使用Socket通信传输文件


前面几篇文章介绍了使用Java的Socket编程和NIO包在Socket中的应用，这篇文章说说怎样利用Socket编程来实现简单的文件传输。

这里由于前面一片文章介绍了NIO在Socket中的应用，所以这里在读写文件的时候也继续使用NIO包，所以代码看起来会比直接使用流的方式稍微复杂一点点。

下面的示例演示了客户端向服务器端发送一个文件，服务器作为响应给客户端会发一个文件。这里准备两个文件E:/test/server_send.log和E:/test/client.send.log文件，在测试完毕后在客户端和服务器相同目录下会多出两个文件E:/test/server_receive.log和E:/test/client.receive.log文件。

下面首先来看看Server类，主要关注其中的sendFile和receiveFile方法。

[java] view plaincopyprint?

    package com.googlecode.garbagecan.test.socket.nio; 
     
    import java.io.File; 
    import java.io.FileInputStream; 
    import java.io.FileOutputStream; 
    import java.io.IOException; 
    import java.net.InetSocketAddress; 
    import java.nio.ByteBuffer; 
    import java.nio.channels.ClosedChannelException; 
    import java.nio.channels.FileChannel; 
    import java.nio.channels.SelectionKey; 
    import java.nio.channels.Selector; 
    import java.nio.channels.ServerSocketChannel; 
    import java.nio.channels.SocketChannel; 
    import java.util.Iterator; 
    import java.util.logging.Level; 
    import java.util.logging.Logger; 
     
    public class MyServer4 { 
     
        private final static Logger logger = Logger.getLogger(MyServer4.class.getName()); 
         
        public static void main(String[] args) { 
            Selector selector = null; 
            ServerSocketChannel serverSocketChannel = null; 
             
            try { 
                // Selector for incoming time requests 
                selector = Selector.open(); 
     
                // Create a new server socket and set to non blocking mode 
                serverSocketChannel = ServerSocketChannel.open(); 
                serverSocketChannel.configureBlocking(false); 
                 
                // Bind the server socket to the local host and port 
                serverSocketChannel.socket().setReuseAddress(true); 
                serverSocketChannel.socket().bind(new InetSocketAddress(10000)); 
                 
                // Register accepts on the server socket with the selector. This 
                // step tells the selector that the socket wants to be put on the 
                // ready list when accept operations occur, so allowing multiplexed 
                // non-blocking I/O to take place. 
                serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT); 
         
                // Here's where everything happens. The select method will 
                // return when any operations registered above have occurred, the 
                // thread has been interrupted, etc. 
                while (selector.select() > 0) { 
                    // Someone is ready for I/O, get the ready keys 
                    Iterator<SelectionKey> it = selector.selectedKeys().iterator(); 
         
                    // Walk through the ready keys collection and process date requests. 
                    while (it.hasNext()) { 
                        SelectionKey readyKey = it.next(); 
                        it.remove(); 
                         
                        // The key indexes into the selector so you 
                        // can retrieve the socket that's ready for I/O 
                        doit((ServerSocketChannel) readyKey.channel()); 
                    } 
                } 
            } catch (ClosedChannelException ex) { 
                logger.log(Level.SEVERE, null, ex); 
            } catch (IOException ex) { 
                logger.log(Level.SEVERE, null, ex); 
            } finally { 
                try { 
                    selector.close(); 
                } catch(Exception ex) {} 
                try { 
                    serverSocketChannel.close(); 
                } catch(Exception ex) {} 
            } 
        } 
     
        private static void doit(final ServerSocketChannel serverSocketChannel) throws IOException { 
            SocketChannel socketChannel = null; 
            try { 
                socketChannel = serverSocketChannel.accept(); 
                 
                receiveFile(socketChannel, new File("E:/test/server_receive.log")); 
                sendFile(socketChannel, new File("E:/test/server_send.log")); 
            } finally { 
                try { 
                    socketChannel.close(); 
                } catch(Exception ex) {} 
            } 
             
        } 
         
        private static void receiveFile(SocketChannel socketChannel, File file) throws IOException { 
            FileOutputStream fos = null; 
            FileChannel channel = null; 
             
            try { 
                fos = new FileOutputStream(file); 
                channel = fos.getChannel(); 
                ByteBuffer buffer = ByteBuffer.allocateDirect(1024); 
     
                int size = 0; 
                while ((size = socketChannel.read(buffer)) != -1) { 
                    buffer.flip(); 
                    if (size > 0) { 
                        buffer.limit(size); 
                        channel.write(buffer); 
                        buffer.clear(); 
                    } 
                } 
            } finally { 
                try { 
                    channel.close(); 
                } catch(Exception ex) {} 
                try { 
                    fos.close(); 
                } catch(Exception ex) {} 
            } 
        } 
     
        private static void sendFile(SocketChannel socketChannel, File file) throws IOException { 
            FileInputStream fis = null; 
            FileChannel channel = null; 
            try { 
                fis = new FileInputStream(file); 
                channel = fis.getChannel(); 
                ByteBuffer buffer = ByteBuffer.allocateDirect(1024); 
                int size = 0; 
                while ((size = channel.read(buffer)) != -1) { 
                    buffer.rewind(); 
                    buffer.limit(size); 
                    socketChannel.write(buffer); 
                    buffer.clear(); 
                } 
                socketChannel.socket().shutdownOutput(); 
            } finally { 
                try { 
                    channel.close(); 
                } catch(Exception ex) {} 
                try { 
                    fis.close(); 
                } catch(Exception ex) {} 
            } 
        } 
    } 

下面是Client程序代码，也主要关注sendFile和receiveFile方法

[java] view plaincopyprint?

    package com.googlecode.garbagecan.test.socket.nio; 
     
    import java.io.File; 
    import java.io.FileInputStream; 
    import java.io.FileOutputStream; 
    import java.io.IOException; 
    import java.net.InetSocketAddress; 
    import java.net.SocketAddress; 
    import java.nio.ByteBuffer; 
    import java.nio.channels.FileChannel; 
    import java.nio.channels.SocketChannel; 
    import java.util.logging.Level; 
    import java.util.logging.Logger; 
     
    public class MyClient4 { 
     
        private final static Logger logger = Logger.getLogger(MyClient4.class.getName()); 
         
        public static void main(String[] args) throws Exception { 
            new Thread(new MyRunnable()).start(); 
        } 
         
        private static final class MyRunnable implements Runnable { 
            public void run() { 
                SocketChannel socketChannel = null; 
                try { 
                    socketChannel = SocketChannel.open(); 
                    SocketAddress socketAddress = new InetSocketAddress("localhost", 10000); 
                    socketChannel.connect(socketAddress); 
     
                    sendFile(socketChannel, new File("E:/test/client_send.log")); 
                    receiveFile(socketChannel, new File("E:/test/client_receive.log")); 
                } catch (Exception ex) { 
                    logger.log(Level.SEVERE, null, ex); 
                } finally { 
                    try { 
                        socketChannel.close(); 
                    } catch(Exception ex) {} 
                } 
            } 
     
            private void sendFile(SocketChannel socketChannel, File file) throws IOException { 
                FileInputStream fis = null; 
                FileChannel channel = null; 
                try { 
                    fis = new FileInputStream(file); 
                    channel = fis.getChannel(); 
                    ByteBuffer buffer = ByteBuffer.allocateDirect(1024); 
                    int size = 0; 
                    while ((size = channel.read(buffer)) != -1) { 
                        buffer.rewind(); 
                        buffer.limit(size); 
                        socketChannel.write(buffer); 
                        buffer.clear(); 
                    } 
                    socketChannel.socket().shutdownOutput(); 
                } finally { 
                    try { 
                        channel.close(); 
                    } catch(Exception ex) {} 
                    try { 
                        fis.close(); 
                    } catch(Exception ex) {} 
                } 
            } 
     
            private void receiveFile(SocketChannel socketChannel, File file) throws IOException { 
                FileOutputStream fos = null; 
                FileChannel channel = null; 
                 
                try { 
                    fos = new FileOutputStream(file); 
                    channel = fos.getChannel(); 
                    ByteBuffer buffer = ByteBuffer.allocateDirect(1024); 
     
                    int size = 0; 
                    while ((size = socketChannel.read(buffer)) != -1) { 
                        buffer.flip(); 
                        if (size > 0) { 
                            buffer.limit(size); 
                            channel.write(buffer); 
                            buffer.clear(); 
                        } 
                    } 
                } finally { 
                    try { 
                        channel.close(); 
                    } catch(Exception ex) {} 
                    try { 
                        fos.close(); 
                    } catch(Exception ex) {} 
                } 
            } 
        } 
    } 

首先运行MyServer4类启动监听，然后运行MyClient4类来向服务器发送文件以及接受服务器响应文件。运行完后，分别检查服务器和客户端接收到的文件。
http://blog.csdn.net/kongxx/article/details/7319410