1、java 网络文件传输的实现Socket 编程All Rights Reserved! 本程序分为服务器和客户端两个小程序。主要实现的功能是：客户端向服务器端请求一个文件的传输连接，服务器接收到请求命令后，要求客户端发送用户名和密码，如果正确，就执行传输文件的过程，客户端接收完后，保存到一个文件中并在屏幕上显示出来。设计原理：服务器端建立一个 SocketServer 等待客户端的连接，每来一个客户端的请求连接，就创建一个新的线程对其进行单独服务，然后继续等待其他的客户端的连接。客户端向服务器发送文件传输请求，在服务器端要求鉴权时，输入用户名和密码发送给服务器验证，如果验证通过就开始文件传输。
2、使用方法，如果需要重新编译的话输入以下两条命令：javac SendFileSocket.javajavac SendFileClient.java在命令行下的运行方式：服务器端：java SendFileSocket客户端：java SendFileClient serverIPAddress例如:java SendFileClient 192.168.0.153服务器程序：/package zieckey.socket;import .*;import java.io.*;/* 一个简单的多线程服务器程序,用于传输文件* * author zieckey*/public class Sen
3、dFileSocket extends Thread/* param args*/public static void main( String args )/*if ( args.length 0 ) / 如果有参数输入就启动服务器程序server( ); else/ 否则启动客户端进程client( );*/server( );/启动服务器程序private static final int PORT = 6000;private Socket s;private static final String name = “zieckey“;private static final Strin
4、g password = “123456“;public SendFileSocket( Socket s )this.s = s;public void run()tryOutputStream os = s.getOutputStream( );InputStream is = s.getInputStream( );os.write( “Hello,welcome you!“.getBytes( ) );byte buf = new byte100;while ( true )int len = is.read( buf );String revStr = new String( buf
5、, 0, len );System.out.println( “This client wants to “+revStr );String fileName;if ( revStr.startsWith( “get “ ) )/表明客户端请求传输一个文件os.write( “Please input your name and password! Using the format:namepassword“.getBytes( ) );fileName = getFileName( revStr );len = is.read( buf );revStr = new String( buf,
6、 0, len );System.out.println( “The received user name and password:“+revStr);if ( revStr.startsWith( “zieckey123456“ ) )FileInputStream fins = new FileInputStream( fileName );/byte fielBuf = new byte100;int data;while ( -1 != ( data = fins.read( ) ) )/从文件中读取数据，每次读取 1 字节os.write( data ); /将读取到的数据写到网络
7、数据流中发送给客户段break; elseos.write( “geting files usage is:get filename“.getBytes( ) );os.close( );is.close( );s.close( ); catch ( Exception e )e.printStackTrace( );/* * 作用：从客户端发来了文件请求命令中提取出所请求的文件名* 参数：客户端发来了文件请求命令字符串，应该以“get ”开头* 返回值：提取出所请求的文件名*/private String getFileName( String revStr )String fileName
8、;fileName = revStr.substring( 3 );while ( fileName.startsWith( “ “ ) )fileName = fileName.substring( 1 );return fileName;public static void server()System.out.println( “This is server“ );tryServerSocket ss = new ServerSocket( PORT );int count = 0;while ( true )/ 创建一个 Socket 等待客户端连接Socket s = ss.acce
9、pt( );count+ ;System.out.println( “This is the “ + count + “st client connetion!“ );new SendFileSocket( s ).start( );/ 启动一个线程为这个客户端服务 catch ( Exception ex )ex.printStackTrace( );/*public static void client()System.out.println( “This is client“ );try/ 创建一个 SocketSocket s = new Socket( InetAddress.get
10、ByName( null ), PORT );OutputStream os = s.getOutputStream( );/ 输出流InputStream is = s.getInputStream( );/ 输入流byte buf = new byte100;int len = is.read( buf );/ 从输入流中读取数据到 bufSystem.out.println( new String( buf, 0, len ) );/ 向输出流中写入数据,请求传输一个文件os.write( “get server.txt“.getBytes( ) );len = is.read( buf
11、 );/ 从输入流中读取数据到 bufString tempStr = new String(buf,0,len);if ( tempStr.startsWith( “Please input your name and password“ ) )System.out.print(“Please input your name and password, “);System.out.print(“Using the format:namepassword:“);System.in.read( buf );os.write( buf );/开始读取文件数据并把它写到一个名为“clientread
12、.txt“的文件中FileOutputStream fos = new FileOutputStream( “clientread.txt“ );int data;while ( -1 != ( data = is.read( ) ) )fos.write( data );System.out.println(“nFile has been recerved successfully.“);os.close( );is.close( );s.close( ); catch ( Exception ex )ex.printStackTrace( );*/客户端程序：import java.io.
13、FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import .InetAddress;import .InetSocketAddress;import .Socket;public class SendFileClientprivate static final int Server_PORT = 6000;private static final int Client_PORT = 6001;/* 使用方法：运行这个程序需要带上参数，参数类型
14、为点分十进制的 ip 地址，例如：192.168.0.153* param args* throws IOException */public static void main( String args ) throws IOException/ TODO Auto-generated method stubSystem.out.println( “This is client“ );/*System.out.print(“Please input your name and password, “);System.out.print(“Using the format:namepasswor
15、d:“);byte buf = new byte100;System.in.read( buf );*/byte buf = new byte100;byte name = new byte100;/InetAddress inetAddr;if ( !isIPAddress(args0) )System.out.println(“The usage is : java SendFileClient ipaddress“);System.out.println(“For example : java SendFileClient 192.168.0.153“);return;String ip
16、Str = args0;try/ 创建一个 SocketSocket s = new Socket();s.connect ( new InetSocketAddress (ipStr , Server_PORT ), Client_PORT );OutputStream os = s.getOutputStream( );/ 输出流InputStream is = s.getInputStream( );/ 输入流int len = is.read( buf );/ 从输入流中读取数据到 bufSystem.out.println( new String( buf, 0, len ) );/
17、 向输出流中写入数据,请求传输一个文件os.write( “get server.txt“.getBytes( ) );len = is.read( buf );/ 从输入流中读取数据到 bufString tempStr = new String(buf,0,len);if ( tempStr.startsWith( “Please input your name and password“ ) )System.out.println(“Please input your name and password, “);System.out.println(“Using the format:n
18、amepassword:“);doSystem.in.read( name ); while ( name.length5 );os.write( name );/开始读取文件数据并把它写到一个名为“clientread.txt“的文件中FileOutputStream fos = new FileOutputStream( “clientread.txt“ );int data;while ( -1 != ( data = is.read( ) ) )fos.write( data );System.out.println(“nFile has been recerved successfully.“);os.close( );is.close( );s.close( ); catch ( Exception ex )ex.printStackTrace( );/简单的判断字符串是否为一个 ip 地址/后期再完善该判断方法private static boolean isIPAddress( String ip )if(ip.length( )5)return false; elsereturn true;
