package cn.example.socket;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.PrintWriter;

import java.net.Socket;

import java.net.UnknownHostException;

public class MyClient {

    public static void main(String[] args) throws UnknownHostException,

            IOException {

        // 定义socket

        Socket socket = new Socket("localhost", 9999);

        // 获取输入输出

        InputStream inputStream = socket.getInputStream();

        OutputStream outputStream = socket.getOutputStream();

        // 处理

        PrintWriter pw = new PrintWriter(outputStream);

        pw.print("hello " + "socket\n");//换行符

        pw.flush();

        //pw.close();//不能关闭 Exception in thread "main" java.net.SocketException: socket closed

        String result = new BufferedReader(new InputStreamReader(inputStream))

                .readLine();

        System.out.println(result);

        inputStream.close();

        outputStream.close();

    }

}

package cn.example.socket;

import java.io.BufferedReader;

import java.io.IOException;

import java.io.InputStream;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.PrintWriter;

import java.net.InetSocketAddress;

import java.net.ServerSocket;

import java.net.Socket;

public class MyServer {

    public static void main(String[] args) throws IOException {

        //建立server

        ServerSocket serverSocket = new ServerSocket();

        //绑定Ip

        serverSocket.bind(new InetSocketAddress("localhost", 9999));

        //启用一个线程处理

        while(true){

            System.out.println("server start");

            new Thread(new MysocketThread(serverSocket.accept())).start();

        }

    }

}

class MysocketThread implements Runnable {

    private Socket socket;

    InputStream inputStream = null;

    OutputStream outputStream = null;

    public MysocketThread(Socket socket) {

        super();

        this.socket = socket;

    }

    @Override

    public void run() {

        try {

            //定义输入输出流

            inputStream = socket.getInputStream();

            outputStream = socket.getOutputStream();

            //解析读入数据

            BufferedReader br = new BufferedReader(new InputStreamReader(inputStream));

            String param = br.readLine();

            //根据读入的数据处理业务逻辑，然后返回，这里简单返回

            String backValue = "ok "+param+"\n";

            PrintWriter pw = new PrintWriter(outputStream);

            pw.print(backValue);

            pw.flush();

            pw.close();

        } catch (IOException e) {

            // TODO Auto-generated catch block

            e.printStackTrace();

        }

        finally{

            try {

                socket.close();

            } catch (IOException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

            try {

                outputStream.close();

            } catch (IOException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

            try {

                inputStream.close();

            } catch (IOException e) {

                // TODO Auto-generated catch block

                e.printStackTrace();

            }

        }

    }

}