nodejs开发nodejs实现socket网络通信

Posted 2022-10-09

(本节内容如下：)

1、简介

在NodeJS中有三种socket：1. TCP，2. UDP，3. Unix域套接字。

UDP/datagram sockets

Class: dgram.Socket
Event: close
Event: connect
Event: error
Event: listening
Event: message
socket.addMembership(multicastAddress[, multicastInterface])
socket.addSourceSpecificMembership(sourceAddress, groupAddress[, multicastInterface])
socket.address()
socket.bind([port][, address][, callback])
socket.bind(options[, callback])
socket.close([callback])
socket.connect(port[, address][, callback])
socket.disconnect()
socket.dropMembership(multicastAddress[, multicastInterface])
socket.dropSourceSpecificMembership(sourceAddress, groupAddress[, multicastInterface])
socket.getRecvBufferSize()
socket.getSendBufferSize()
socket.ref()
socket.remoteAddress()
socket.send(msg[, offset, length][, port][, address][, callback])
Note about UDP datagram size
socket.setBroadcast(flag)
socket.setMulticastInterface(multicastInterface)
Example: IPv6 outgoing multicast interface
Example: IPv4 outgoing multicast interface
Call results
socket.setMulticastLoopback(flag)
socket.setMulticastTTL(ttl)
socket.setRecvBufferSize(size)
socket.setSendBufferSize(size)
socket.setTTL(ttl)
socket.unref()
dgram module functions
dgram.createSocket(options[, callback])
dgram.createSocket(type[, callback])

2、UDP单播

The dgram module provides an implementation of UDP datagram sockets.

2.1 接收端

• server.js

const dgram = require(dgram);
const server = dgram.createSocket(udp4);

server.on(error, (err) => 
  console.log(`server error:\\n$err.stack`);
  server.close();
);

server.on(message, (msg, rinfo) => 
  console.log(`server got: $msg from $rinfo.address:$rinfo.port`);
);

server.on(listening, () => 
  const address = server.address();
  console.log(`server listening $address.address:$address.port`);
);

server.bind(41234);
// Prints: server listening 0.0.0.0:41234

nodejs接收端的运行截图如下：

测试c++发送端的运行截图如下：

2.2 发送端

例子1：

const dgram = require(dgram);

const message = Buffer.from(Some bytes);
const client = dgram.createSocket(udp4);
client.send(message, 41234, localhost, (err) => 
  client.close();
);

例子2：

const dgram = require(dgram);
const buf1 = Buffer.from(Some );
const buf2 = Buffer.from(bytes);
const client = dgram.createSocket(udp4);
client.send([buf1, buf2], 41234, (err) => 
  client.close();
);

例子3：

const dgram = require(dgram);
const message = Buffer.from(Some bytes);
const client = dgram.createSocket(udp4);
client.connect(41234, localhost, (err) => 
  client.send(message, (err) => 
    client.close();
  );
);

3、UDP组播

3.1 发送端

const dgram = require(dgram);
const server = dgram.createSocket(udp4);

// const local_ip = "192.168.0.xx";
const multicast_ip = "225.0.0.100"; // 这里必须是一个组播地址(D类IP地址)

server.on(close, () => 
    console.log(close socket);
);

server.on(listening, () => 
    console.log(listening... );
    server.setBroadcast(true);
    server.setMulticastTTL(128);
    server.addMembership(multicast_ip);

    setInterval(() => 
        send_msg();
    , 2000);
);

server.on(message, (msg, rinfo) => 
    console.log(`receive client message from $rinfo.address: $rinfo.port: $msg`);
);

server.bind(); // 随机绑定本机一个端口

function send_msg() 
    var date = new Date();
    console.log(date.toLocaleDateString() + " " + date.toLocaleTimeString() + : send a message.);
    server.send(hi, i am server..., 8062, multicast_ip);

3.2 接收端

const dgram = require(dgram);
var client = dgram.createSocket(udp4);

// const local_ip = 192.168.0.xx;
const multicast_ip = "225.0.0.100"; // 这里必须是一个组播地址(D类IP地址)

client.on(close, () => 
    console.log(client closed);
);

client.on(error, (err) => 
    console.log(client error + err);
);

client.on(listening, () => 
    console.log(client listening...);
    client.setBroadcast(true);
    client.setMulticastTTL(128);
    client.addMembership(multicast_ip);
);

client.on(message, (msg, rinfo) => 
    console.log(`receive server message from $rinfo.address: $rinfo.port: $msg`);
);
client.bind(8062); // 监听组播数据的端口

测试接收端1结果如下： 测试接收端2结果如下：