Socket介绍及使用Java实现socket通信前后端示例代码

本文介绍一下再Java中Socket的实现。

目录

一、需要掌握

二、程序源码

三、运行演示

一、介绍

Java Socket实现实时接收TCP消息需要客户端和服务端两个部分。

二、JavaSocket源码示例

客户端后台部分代码

public class Client {
    public static void main(String[] args) {

        try (Socket socket = new Socket("localhost", 1234)) {
            BufferedReader in = new BufferedReader(
                new InputStreamReader(socket.getInputStream()));
            while (true) {
                String message = in.readLine();
                if (message == null) {
                    break;
                }
                System.out.println("Received message: " + message);
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

服务端后台部分代码

public class Server {
    public static void main(String[] args) {

        try (ServerSocket serverSocket = new ServerSocket(1234)) {
            System.out.println("Server started");

            while (true) {
                Socket clientSocket = serverSocket.accept();
                System.out.println("Client connected: " + clientSocket.getInetAddress());

                PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
                out.println("Welcome to the server");

                BufferedReader in = new BufferedReader(
                    new InputStreamReader(clientSocket.getInputStream()));
                while (true) {
                    String message = in.readLine();
                    if (message == null) {
                        break;
                    }
                    System.out.println("Received message: " + message);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

以上代码演示了客户端连接到指定的服务端Socket，接收到服务端发送的消息，并在控制台输出。

三、WebSocket源码示例

前端范例

var socket = new WebSocket("ws://localhost:1234");

socket.onmessage = function(event) {
    console.log("Received message: " + event.data);
};

以上代码演示了使用WebSocket连接到指定的服务器，接收到消息时在控制台输出。

后端范例

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

import javax.websocket.OnMessage;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

@ServerEndpoint("/echo")
public class WebSocketServer {

    @OnMessage
    public void onMessage(String message, Session session) {
        try {
            session.getBasicRemote().sendText("Received message: " + message);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    
    public static void main(String[] args) {

        try (ServerSocket serverSocket = new ServerSocket(1234)) {
            System.out.println("Server started");

            while (true) {
                Socket clientSocket = serverSocket.accept();
                System.out.println("Client connected: " + clientSocket.getInetAddress());

                PrintWriter out = new PrintWriter(clientSocket.getOutputStream(), true);
                out.println("Welcome to the server");

                BufferedReader in = new BufferedReader(
                    new InputStreamReader(clientSocket.getInputStream()));
                while (true) {
                    String message = in.readLine();
                    if (message == null) {
                        break;
                    }
                    System.out.println("Received message: " + message);
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

以上代码演示了使用WebSocket实现服务端接收消息，并将接收到的消息原样发送回客户端。