Sockt编程（多线程）

服务器端：

package com.zeph.serverclient;  

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;  

public class MyServer {
    public static void main(String[] args) throws IOException {
        ServerSocket server = new ServerSocket(5678);
        Socket client = server.accept();
        BufferedReader in = new BufferedReader(new InputStreamReader(
                client.getInputStream()));
        PrintWriter out = new PrintWriter(client.getOutputStream());
        while (true) {
            String str = in.readLine();
            System.out.println(str);
            out.println("has receive....");
            out.flush();
            if (str.equals("end"))
                break;
        }
        client.close();
    }
}

客户端：

package com.zeph.serverclient;  

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;  

public class MyClient {
    static Socket server;  

    public static void main(String[] args) throws Exception {
        server = new Socket(InetAddress.getLocalHost(), 5678);
        BufferedReader in = new BufferedReader(new InputStreamReader(
                server.getInputStream()));
        PrintWriter out = new PrintWriter(server.getOutputStream());
        BufferedReader wt = new BufferedReader(new InputStreamReader(System.in));
        while (true) {
            String str = wt.readLine();
            out.println(str);
            out.flush();
            if (str.equals("end")) {
                break;
            }
            System.out.println(in.readLine());
        }
        server.close();
    }
}  

服务器端（多线程）

package com.zeph.multiclient;  

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;  

public class MultiClient extends Thread {
    private Socket client;  

    public MultiClient(Socket c) {
        this.client = c;
    }  

    public void run() {
        try {
            BufferedReader in = new BufferedReader(new InputStreamReader(
                    client.getInputStream()));
            PrintWriter out = new PrintWriter(client.getOutputStream());
            // Mutil User but can't parallel  

            while (true) {
                String str = in.readLine();
                System.out.println(str);
                out.println("has receive....");
                out.flush();
                if (str.equals("end"))
                    break;
            }
            client.close();
        } catch (IOException ex) {
        } finally {
        }
    }  

    public static void main(String[] args) throws IOException {
        ServerSocket server = new ServerSocket(5678);  //绑定端口
        while (true) {
            // transfer location change Single User or Multi User  

            MultiClient mc = new MultiClient(server.accept());  //阻塞进程，等待客户端的连接
            mc.start();
        }
    }
}

服务器基本步骤：

1.指定端口实例化一个SeverSocket，绑定端口

2.调用ServerSocket的accept()方法，以在等待连接期间造成阻塞

3.获取位于该底层的Socket的流以进行读写操作

4.将数据封装成流

5.对Socket进行读写

6.关闭打开的流

客户端基本步骤：

1.通过IP地址和端口实例化Socket，请求连接服务器

2.获得Socket上的流以进行读写

3.把流封装进BufferedReader/PrintWriter的实例

4.对Socket进行读写

5.关闭打开的流