springboot如何开启socket

Posted 2022-08-26 程序员超时空

1.创建socket服务类代码

package com.example.springbootsocket;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.Selector;
import java.nio.channels.ServerSocketChannel;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.util.Set;

/**
 * nio socket服务端
 */
public class SocketServer 
    //解码buffer
    private Charset cs = Charset.forName("UTF-8");
    //接受数据缓冲区
    private static ByteBuffer sBuffer = ByteBuffer.allocate(1024);
    //发送数据缓冲区
    private static ByteBuffer rBuffer = ByteBuffer.allocate(1024);
    //选择器（叫监听器更准确些吧应该）
    private static Selector selector;

    /**
     * 启动socket服务，开启监听
     *
     * @param port
     * @throws IOException
     */
    public void startSocketServer(int port) 
        try 
            //打开通信信道
            ServerSocketChannel serverSocketChannel = ServerSocketChannel.open();
            //设置为非阻塞
            serverSocketChannel.configureBlocking(false);
            //获取套接字
            ServerSocket serverSocket = serverSocketChannel.socket();
            //绑定端口号
            serverSocket.bind(new InetSocketAddress(port));
            //打开监听器
            selector = Selector.open();
            //将通信信道注册到监听器
            serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);

            //监听器会一直监听，如果客户端有请求就会进入相应的事件处理
            while (true) 
                selector.select();//select方法会一直阻塞直到有相关事件发生或超时
                Set<SelectionKey> selectionKeys = selector.selectedKeys();//监听到的事件
                for (SelectionKey key : selectionKeys) 
                    handle(key);
                
                selectionKeys.clear();//清除处理过的事件
            
         catch (Exception e) 
            e.printStackTrace();
        


    

    /**
     * 处理不同的事件
     *
     * @param selectionKey
     * @throws IOException
     */
    private void handle(SelectionKey selectionKey) throws IOException 
        ServerSocketChannel serverSocketChannel = null;
        SocketChannel socketChannel = null;
        String requestMsg = "";
        int count = 0;
        if (selectionKey.isAcceptable()) 
            //每有客户端连接，即注册通信信道为可读
            serverSocketChannel = (ServerSocketChannel) selectionKey.channel();
            socketChannel = serverSocketChannel.accept();
            socketChannel.configureBlocking(false);
            socketChannel.register(selector, SelectionKey.OP_READ);
         else if (selectionKey.isReadable()) 
            socketChannel = (SocketChannel) selectionKey.channel();
            rBuffer.clear();
            count = socketChannel.read(rBuffer);
            //读取数据
            if (count > 0) 
                rBuffer.flip();
                requestMsg = String.valueOf(cs.decode(rBuffer).array());
            
            String responseMsg = "已收到客户端的消息:" + requestMsg;
            System.out.println(responseMsg);
            //返回数据
            sBuffer = ByteBuffer.allocate(responseMsg.getBytes("UTF-8").length);
            sBuffer.put(responseMsg.getBytes("UTF-8"));
            sBuffer.flip();
            socketChannel.write(sBuffer);
            socketChannel.close();
        
    

2.在 springboot 启动类 main 方法中添加 socket 服务端启动代码

package com.example.springbootsocket;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
public class SpringbootSocketApplication 

	public static void main(String[] args) 
		SpringApplication.run(SpringbootSocketApplication.class, args);

		//起socket服务
		SocketServer server = new SocketServer();
		server.startSocketServer(8088);