Java使用Socket通信传输文件的方法示例
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：
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。
packagecom.googlecode.garbagecan.test.socket.nio;
importjava.io.File;
importjava.io.FileInputStream;
importjava.io.FileOutputStream;
importjava.io.IOException;
importjava.net.InetSocketAddress;
importjava.nio.ByteBuffer;
importjava.nio.channels.ClosedChannelException;
importjava.nio.channels.FileChannel;
importjava.nio.channels.SelectionKey;
importjava.nio.channels.Selector;
importjava.nio.channels.ServerSocketChannel;
importjava.nio.channels.SocketChannel;
importjava.util.Iterator;
importjava.util.logging.Level;
importjava.util.logging.Logger;
publicclassMyServer4{
privatefinalstaticLoggerlogger=Logger.getLogger(MyServer4.class.getName());
publicstaticvoidmain(String[]args){
Selectorselector=null;
ServerSocketChannelserverSocketChannel=null;
try{
//Selectorforincomingtimerequests
selector=Selector.open();
//Createanewserversocketandsettononblockingmode
serverSocketChannel=ServerSocketChannel.open();
serverSocketChannel.configureBlocking(false);
//Bindtheserversockettothelocalhostandport
serverSocketChannel.socket().setReuseAddress(true);
serverSocketChannel.socket().bind(newInetSocketAddress(10000));
//Registeracceptsontheserversocketwiththeselector.This
//steptellstheselectorthatthesocketwantstobeputonthe
//readylistwhenacceptoperationsoccur,soallowingmultiplexed
//non-blockingI/Ototakeplace.
serverSocketChannel.register(selector,SelectionKey.OP_ACCEPT);
//Here'swhereeverythinghappens.Theselectmethodwill
//returnwhenanyoperationsregisteredabovehaveoccurred,the
//threadhasbeeninterrupted,etc.
while(selector.select()>0){
//SomeoneisreadyforI/O,getthereadykeys
Iteratorit=selector.selectedKeys().iterator();
//Walkthroughthereadykeyscollectionandprocessdaterequests.
while(it.hasNext()){
SelectionKeyreadyKey=it.next();
it.remove();
//Thekeyindexesintotheselectorsoyou
//canretrievethesocketthat'sreadyforI/O
doit((ServerSocketChannel)readyKey.channel());
}
}
}catch(ClosedChannelExceptionex){
logger.log(Level.SEVERE,null,ex);
}catch(IOExceptionex){
logger.log(Level.SEVERE,null,ex);
}finally{
try{
selector.close();
}catch(Exceptionex){}
try{
serverSocketChannel.close();
}catch(Exceptionex){}
}
}
privatestaticvoiddoit(finalServerSocketChannelserverSocketChannel)throwsIOException{
SocketChannelsocketChannel=null;
try{
socketChannel=serverSocketChannel.accept();
receiveFile(socketChannel,newFile("E:/test/server_receive.log"));
sendFile(socketChannel,newFile("E:/test/server_send.log"));
}finally{
try{
socketChannel.close();
}catch(Exceptionex){}
}
}
privatestaticvoidreceiveFile(SocketChannelsocketChannel,Filefile)throwsIOException{
FileOutputStreamfos=null;
FileChannelchannel=null;
try{
fos=newFileOutputStream(file);
channel=fos.getChannel();
ByteBufferbuffer=ByteBuffer.allocateDirect(1024);
intsize=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(Exceptionex){}
try{
fos.close();
}catch(Exceptionex){}
}
}
privatestaticvoidsendFile(SocketChannelsocketChannel,Filefile)throwsIOException{
FileInputStreamfis=null;
FileChannelchannel=null;
try{
fis=newFileInputStream(file);
channel=fis.getChannel();
ByteBufferbuffer=ByteBuffer.allocateDirect(1024);
intsize=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(Exceptionex){}
try{
fis.close();
}catch(Exceptionex){}
}
}
}
下面是Client程序代码，也主要关注sendFile和receiveFile方法
packagecom.googlecode.garbagecan.test.socket.nio;
importjava.io.File;
importjava.io.FileInputStream;
importjava.io.FileOutputStream;
importjava.io.IOException;
importjava.net.InetSocketAddress;
importjava.net.SocketAddress;
importjava.nio.ByteBuffer;
importjava.nio.channels.FileChannel;
importjava.nio.channels.SocketChannel;
importjava.util.logging.Level;
importjava.util.logging.Logger;
publicclassMyClient4{
privatefinalstaticLoggerlogger=Logger.getLogger(MyClient4.class.getName());
publicstaticvoidmain(String[]args)throwsException{
newThread(newMyRunnable()).start();
}
privatestaticfinalclassMyRunnableimplementsRunnable{
publicvoidrun(){
SocketChannelsocketChannel=null;
try{
socketChannel=SocketChannel.open();
SocketAddresssocketAddress=newInetSocketAddress("localhost",10000);
socketChannel.connect(socketAddress);
sendFile(socketChannel,newFile("E:/test/client_send.log"));
receiveFile(socketChannel,newFile("E:/test/client_receive.log"));
}catch(Exceptionex){
logger.log(Level.SEVERE,null,ex);
}finally{
try{
socketChannel.close();
}catch(Exceptionex){}
}
}
privatevoidsendFile(SocketChannelsocketChannel,Filefile)throwsIOException{
FileInputStreamfis=null;
FileChannelchannel=null;
try{
fis=newFileInputStream(file);
channel=fis.getChannel();
ByteBufferbuffer=ByteBuffer.allocateDirect(1024);
intsize=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(Exceptionex){}
try{
fis.close();
}catch(Exceptionex){}
}
}
privatevoidreceiveFile(SocketChannelsocketChannel,Filefile)throwsIOException{
FileOutputStreamfos=null;
FileChannelchannel=null;
try{
fos=newFileOutputStream(file);
channel=fos.getChannel();
ByteBufferbuffer=ByteBuffer.allocateDirect(1024);
intsize=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(Exceptionex){}
try{
fos.close();
}catch(Exceptionex){}
}
}
}
}
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。
更多关于java相关内容感兴趣的读者可查看本站专题：《JavaSocket编程技巧总结》、《Java文件与目录操作技巧汇总》、《Java数据结构与算法教程》、《Java操作DOM节点技巧总结》和《Java缓存操作技巧汇总》
希望本文所述对大家java程序设计有所帮助。