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本文实例讲述了Java使用Socket通信传输文件的方法。分享给大家供大家参考,具体如下:
网站建设哪家好,找创新互联!专注于网页设计、网站建设、微信开发、小程序设计、集团企业网站建设等服务项目。为回馈新老客户创新互联还提供了叶城免费建站欢迎大家使用!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回发一个文件。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。
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 Iteratorit = 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) {} } } }