java socket简单通信

客户端

import java.io.*;
import java.net.Inet4Address;
import java.net.InetSocketAddress;
import java.net.Socket;

public class Client {
    public static void main(String[] args) throws IOException {
        Socket socket = new Socket();
//        超时时间
        socket.setSoTimeout(3000);

        socket.connect(new InetSocketAddress(Inet4Address.getLocalHost(),2000),3000);

        System.out.println("已经发起服务器连接，并进入后续流程");
        System.out.println("客户端信息:"+socket.getLocalAddress()+"p:"+socket.getLocalPort());

        System.out.println("服务器信息："+socket.getInetAddress()+"p:"+socket.getPort());

        try{
            todo(socket);//发送数据的部分
        }catch (Exception e){
            System.out.println("异常关闭");
        }

        socket.close();
        System.out.println("客户端已经退出");

    }


    private static void todo(Socket client) throws IOException{

        //构建键盘输入流
        InputStream in =System.in;
        BufferedReader input = new BufferedReader(new InputStreamReader(in));

        // 得到socket 输出流，并转化为打印流
        OutputStream outputStream = client.getOutputStream();

        PrintStream scoketPrintStream = new PrintStream(outputStream);

        //得到socket输入流
        InputStream inputStream = client.getInputStream();
        BufferedReader socketBufferReader = new BufferedReader(new InputStreamReader(inputStream));


        boolean flag = true;
        do{
            //键盘读取一行
            String str = input.readLine();

            //发送到服务器
            scoketPrintStream.println(str);

            String echo = socketBufferReader.readLine();

            if("bye".equalsIgnoreCase(echo)){
                flag = false;

            }else {
                System.out.println(echo);
            }

        }while(flag);
        //资源释放
        scoketPrintStream.close();
        socketBufferReader.close();

    }

}

服务端

import java.io.*;
import java.net.*;

public class Server {
    public static void main(String[] args) throws IOException {
        ServerSocket server = new ServerSocket(2000);

        System.out.println("服务器准备就绪");
        System.out.println("服务器信息："+server.getInetAddress()+"p :"+server.getLocalPort());

        for(;;){
            //得到客户端
            Socket client = server.accept();
            // 客户端构建异步线程
            ClientHandler clientHandler = new ClientHandler(client);
            //启动线程
            clientHandler.start();
        }

    }

    private static class ClientHandler extends Thread{
        private Socket socket;
        private boolean flag = true;

        ClientHandler(Socket socket){
            this.socket = socket;
        }

        @Override
        public void run(){
            super.run();
            System.out.println("新客户端连接："+socket.getInetAddress()+"p:"+socket.getPort());

            try{
                //得到打印流，用于数据的输出；服务器回送数据使用
                PrintStream socketOutput = new PrintStream(socket.getOutputStream());

                //得到输入流，用于接收数据
                BufferedReader socketInput = new BufferedReader(new InputStreamReader(socket.getInputStream()));

                do{
                    String str = socketInput.readLine();

                    if("bye".equalsIgnoreCase(str)){
                        flag = false;

                        socketOutput.println("bye");
                    }else{
                        System.out.println(str);
                        socketOutput.println("回送："+str.length());
                    }

                }while (flag);

                socketOutput.close();
                socketInput.close();

            }catch (Exception e){
                System.out.println("连接异常");
            }finally {
                try{
                    socket.close();

                }catch (IOException e){
                    e.printStackTrace();
                }
            }
            System.out.println("客户端已退出："+socket.getInetAddress()+"P :"+socket.getPort());

        }

    }
}