Socket TCP简单案例

爱被打了一巴掌 2022-03-06 12:14 171阅读 0赞

# 1. 流程 #

*  构建TCP客户端、服务端
 *  客户端发送数据，并接收服务器传回的数据长度
 *  服务器接收并打印数据

# 2. 客户端代码 #

**    运行环境：IDEA**

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);
            //连接本地，超时时间3000
            socket.connect(new InetSocketAddress(Inet4Address.getLocalHost(),2000),3000);
            System.out.println("已连接服务器");
            System.out.println("服务器信息："+socket.getLocalAddress()+" port:"+socket.getLocalPort());
            System.out.println("客户端信息:"+socket.getInetAddress()+" port:"+socket.getPort());
    
            try{
                todo(socket);
            }catch(Exception e){
                System.out.println("异常关闭");
            }
    
            //释放资源
            socket.close();
            System.out.println("客户端已退出 ");
    
        }
    
        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));
    
            //得到输出流，转化为打印流
            OutputStream out = client.getOutputStream();
            PrintStream ptStream = new PrintStream(out);
    
            //得到socket输入流,转化为Bufferedreader
            InputStream inputStream = client.getInputStream();
            BufferedReader socketBufferedreader = new BufferedReader(new InputStreamReader(inputStream));
    
            boolean flag=true;
            do{
                //键盘读取一行
                String s = input.readLine();
                //发送到服务器
                ptStream.println(s);
    
                //从服务器读取一行
                String echo = socketBufferedreader.readLine();
                if("bye".equalsIgnoreCase(echo)){
                    flag = false;
                }
                else{
                    System.out.println(echo);
                }
            }while(flag);
    
            //资源释放
            ptStream.close();
            socketBufferedreader.close();
    
        }
    }

# 3. 服务器端代码 #

import java.io.BufferedReader;
    import java.io.IOException;
    import java.io.InputStreamReader;
    import java.io.PrintStream;
    import java.net.ServerSocket;
    import java.net.Socket;
    
    public class Server {
        public static void main(String []args) throws IOException {
    
            ServerSocket serverSocket = new ServerSocket(2000);
            System.out.println("服务器准备就绪");
            System.out.println("服务器信息："+serverSocket.getInetAddress()+" port:"+serverSocket.getLocalPort());
    
            //等待客户端连接
            for(;;){
                //得到客户端
                Socket client = serverSocket.accept();
                //客户端构建异步线程
                ClientHander clientHander = new ClientHander(client);
                //启动线程
                clientHander.start();
    
            }
    
        }
    
        private static class ClientHander extends Thread{
            private Socket socket;
            private boolean flag = true;
            ClientHander(Socket socket){
                this.socket = socket;
            }
    
            @Override
            public void run() {
                super.run();
                System.out.println("新客户端连接："+this.socket.getInetAddress()+" port:"+this.socket.getLocalPort());
    
                try{
                    //得到输出流，用于数据输出
                    PrintStream pstream = new PrintStream(this.socket.getOutputStream());
                    //得到输入流，用于接收数据
                    BufferedReader socketinput = new BufferedReader(new InputStreamReader(this.socket.getInputStream()));
    
                    do{
                        String s = socketinput.readLine();
                        if("bye".equalsIgnoreCase(s)){
                            flag = false;
                            pstream.println("bye");
                        }
                        else{
                            System.out.println(s);
                            pstream.println("回送数据长度："+s.length());
                        }
    
                    }while(flag);
    
                    pstream.close();
                    socketinput.close();
    
                }catch(Exception e){
                    System.out.println("连接异常断开");
                }finally {
                    //关闭连接
                    try{
                        this.socket.close();
                    }catch (IOException e){
                        e.printStackTrace();
                    }
                }
    
                System.out.println("客户端已退出"+this.socket.getInetAddress()+" port:"+this.socket.getLocalPort());
    
            }
        }
    }

# 4. 运行结果 #

可见客户端退出后服务器并未停止，当有新客户端连接时，服务器仍正常连接。

每次客户端连接的服务器端口并不同，但其实都是本地电脑。