java socket

package sterning;  

import java.io.BufferedInputStream;  

import java.io.DataInputStream;  

import java.io.DataOutputStream;  

import java.io.File;  

import java.io.FileInputStream;  

import java.net.ServerSocket;  

import java.net.Socket;  

public class ServerTest {  

    int port = 8821;  

    void start() {  

        Socket s = null;  

        try {  

            ServerSocket ss = new ServerSocket(port);  

            while (true) {  

                // 选择进行传输的文件  

                String filePath = "D:\\lib.rar";  

                File fi = new File(filePath);  

                System.out.println("文件长度:" + (int) fi.length());  

                // public Socket accept() throws  

                // IOException侦听并接受到此套接字的连接。此方法在进行连接之前一直阻塞。  

                s = ss.accept();  

                System.out.println("建立socket链接");  

                DataInputStream dis = new DataInputStream(new BufferedInputStream(s.getInputStream()));  

                dis.readByte();  

                DataInputStream fis = new DataInputStream(new BufferedInputStream(new FileInputStream(filePath)));  

                DataOutputStream ps = new DataOutputStream(s.getOutputStream());  

                //将文件名及长度传给客户端。这里要真正适用所有平台，例如中文名的处理，还需要加工，具体可以参见Think In Java 4th里有现成的代码。  

                ps.writeUTF(fi.getName());  

                ps.flush();  

                ps.writeLong((long) fi.length());  

                int bufferSize = 8192;  

                byte[] buf = new byte[bufferSize];  

                while (true) {  

                    int read = 0;  

                    if (fis != null) {  

                        read = fis.read(buf);  

                    }  

                    if (read == -1) {  

                        break;  

                    ps.write(buf, 0, read);  

                }  

                // 注意关闭socket链接哦，不然客户端会等待server的数据过来，  

                // 直到socket超时，导致数据不完整。                  

                fis.close();  

                s.close();                  

                System.out.println("文件传输完成");  

            }  

        } catch (Exception e) {  

            e.printStackTrace();  

        }  

    }  

    public static void main(String arg[]) {  

        new ServerTest().start();  

}  

2.socket的Util辅助类 

import java.net.*;  

import java.io.*;  

public class ClientSocket {  

    private String ip;  

    private int port;  

    private Socket socket = null;  

    DataOutputStream out = null;  

    DataInputStream getMessageStream = null;  

    public ClientSocket(String ip, int port) {  

        this.ip = ip;  

        this.port = port;  

    /** *//** 

     * 创建socket连接 

     *  

     * @throws Exception 

     *             exception 

     */  

    public void CreateConnection() throws Exception {  

            socket = new Socket(ip, port);  

            if (socket != null)  

                socket.close();  

            throw e;  

        } finally {  

    public void sendMessage(String sendMessage) throws Exception {  

            out = new DataOutputStream(socket.getOutputStream());  

            if (sendMessage.equals("Windows")) {  

                out.writeByte(0x1);  

                out.flush();  

                return;  

            if (sendMessage.equals("Unix")) {  

                out.writeByte(0x2);  

            if (sendMessage.equals("Linux")) {  

                out.writeByte(0x3);  

            } else {  

                out.writeUTF(sendMessage);  

            if (out != null)  

                out.close();  

    public DataInputStream getMessageStream() throws Exception {  

            getMessageStream = new DataInputStream(new BufferedInputStream(socket.getInputStream()));  

            return getMessageStream;  

            if (getMessageStream != null)  

                getMessageStream.close();  

    public void shutDownConnection() {  

3.客户端 

import java.io.BufferedOutputStream;  

import java.io.FileOutputStream;  

public class ClientTest {  

    private ClientSocket cs = null;  

    private String ip = "localhost";// 设置成服务器IP  

    private int port = 8821;  

    private String sendMessage = "Windwos";  

    public ClientTest() {  

            if (createConnection()) {  

                sendMessage();  

                getMessage();  

        } catch (Exception ex) {  

            ex.printStackTrace();  

    private boolean createConnection() {  

        cs = new ClientSocket(ip, port);  

            cs.CreateConnection();  

            System.out.print("连接服务器成功!" + "\n");  

            return true;  

            System.out.print("连接服务器失败!" + "\n");  

            return false;  

    private void sendMessage() {  

        if (cs == null)  

            return;  

            cs.sendMessage(sendMessage);  

            System.out.print("发送消息失败!" + "\n");  

    private void getMessage() {  

        DataInputStream inputStream = null;  

            inputStream = cs.getMessageStream();  

            System.out.print("接收消息缓存错误\n");  

            //本地保存路径，文件名会自动从服务器端继承而来。  

            String savePath = "E:\\";  

            int bufferSize = 8192;  

            byte[] buf = new byte[bufferSize];  

            int passedlen = 0;  

            long len=0;  

            savePath += inputStream.readUTF();  

            DataOutputStream fileOut = new DataOutputStream(new BufferedOutputStream(new BufferedOutputStream(new FileOutputStream(savePath))));  

            len = inputStream.readLong();  

            System.out.println("文件的长度为:" + len + "\n");  

            System.out.println("开始接收文件!" + "\n");  

                int read = 0;  

                if (inputStream != null) {  

                    read = inputStream.read(buf);  

                passedlen += read;  

                if (read == -1) {  

                    break;  

                //下面进度条本为图形界面的prograssBar做的，这里如果是打文件，可能会重复打印出一些相同的百分比  

                System.out.println("文件接收了" +  (passedlen * 100/ len) + "%\n");  

                fileOut.write(buf, 0, read);  

            System.out.println("接收完成，文件存为" + savePath + "\n");  

            fileOut.close();  

            System.out.println("接收消息错误" + "\n");  

        new ClientTest();