Socket协议网上介绍的有很多了，就不在画蛇添足了，本文主要编写一个小Demo,介绍下它具体实现

一：Socket服务器端

package com.founderit;

import java.io.*;
import java.net.ServerSocket;
import java.net.Socket;

public class HelloServer {

    public static void main(String[] args) {
        InputStream in = null;
        OutputStream out = null;
        try {
            ServerSocket serverSocket= new ServerSocket(1234);
            while (true){
               Socket socket= serverSocket.accept();
                in=socket.getInputStream();
               InputStreamReader reader= new InputStreamReader(in);
                StringBuilder builder=new StringBuilder();
                for (int c = reader.read(); c != -1; c = reader.read()) {
                    builder.append((char)c);
                }
                System.out.println("收到的客户端请求为：-------"+builder.toString());
                out=socket.getOutputStream();
                out.write("请求已接收，over".getBytes());
                out.flush();
                socket.shutdownOutput();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                in.close();
                out.close();
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}

二：Socket客户端

package com.founderit.controller;

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

public class SocketClient {
    public static void main(String[] args) {
        OutputStream out=null;
        InputStream in=null;
        Socket socket=null;
        try {
            socket=new Socket("localhost",1234);
            out=socket.getOutputStream();
            out.write("呼叫服务器，收到请回答".getBytes());
            socket.shutdownOutput();
            //获取输入流，并读取服务器端的响应信息
            in=socket.getInputStream();
            BufferedReader br=new BufferedReader(new InputStreamReader(in));
            StringBuilder sb=new StringBuilder();
            String info=null;
            while ((info=br.readLine())!=null){
                sb.append(info);
            }
            System.out.println("收到服务端回复："+sb.toString());
            br.close();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            try {
                out.flush();
                out.close();
                in.close();
                socket.close();
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }

}

首先执行Socket服务端，它会一直运行等待接收请求，创建socketServer需要绑定端口，这个端口需需要与客户端一致
然后执行Socket客户端，它会发送Socket请求给服务端并接收服务器端反馈，运行效果如下

 需要注意的是无论是客户端与服务端，执行write()方法后最好执行socket.shutdownOutput()方法关闭输出流，不然有几率写入不成功（原因未知）