本文實(shí)例講述了Java使用Socket通信傳輸文件的方法。分享給大家供大家參考，具體如下：
前面幾篇文章介紹了使用Java的Socket編程和NIO包在Socket中的應(yīng)用，這篇文章說(shuō)說(shuō)怎樣利用Socket編程來(lái)實(shí)現(xiàn)簡(jiǎn)單的文件傳輸。
這里由于前面一片文章介紹了NIO在Socket中的應(yīng)用，所以這里在讀寫文件的時(shí)候也繼續(xù)使用NIO包，所以代碼看起來(lái)會(huì)比直接使用流的方式稍微復(fù)雜一點(diǎn)點(diǎn)。
下面的示例演示了客戶端向服務(wù)器端發(fā)送一個(gè)文件，服務(wù)器作為響應(yīng)給客戶端回發(fā)一個(gè)文件。這里準(zhǔn)備兩個(gè)文件E:/test/server_send.log和E:/test/client.send.log文件，在測(cè)試完畢后在客戶端和服務(wù)器相同目錄下會(huì)多出兩個(gè)文件E:/test/server_receive.log和E:/test/client.receive.log文件。
下面首先來(lái)看看Server類，主要關(guān)注其中的sendFile和receiveFile方法。
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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程序代碼，也主要關(guān)注sendFile和receiveFile方法
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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) {} } } }} |
首先運(yùn)行MyServer4類啟動(dòng)監(jiān)聽，然后運(yùn)行MyClient4類來(lái)向服務(wù)器發(fā)送文件以及接受服務(wù)器響應(yīng)文件。運(yùn)行完后，分別檢查服務(wù)器和客戶端接收到的文件。
希望本文所述對(duì)大家java程序設(shè)計(jì)有所幫助。
