TCP/UDP网络应用
创建TCP服务器客户端
-
socket套接字对象实例，是对TCP协议的一个基本封装接口
-
clientt套接字对象实例
//server.js
var net = require('net');
var HOST = '127.0.0.1';
var PORT = 9694;
var server = net.createServer(function (socket) {
console.log('Server listening on ' + HOST + ':' + PORT);
console.log('CONNECTED: ' + socket.remoteAddress + ':' + socket.remotePort);
socket.on('data', function (data) {
console.log('DATA ' + socket.remoteAddress + ':"' + data + '"');
socket.write('Server write: this is server')
})
socket.on('close', function (data) {
console.log('CLOSED: ' + socket.remoteAddress + ' ' + socket.remotePort);
})
})
server.listen(PORT, HOST)
//client.js
var net = require('net');
var HOST = '127.0.0.1';
var PORT = 9694;
var client = net.connect(PORT, HOST, function () {
console.log('client connected');
client.write('client write: this is client');
})
client.on('data', function (data) {
console.log(data.toString());
client.end();
})
client.on('end', function () {
console.log('client disconnected');
})
List open files on a port and copy PID
lsof -i :<port>
Kill it with fire :)
kill -9 <PID>
另一种方法创建服务器
var net = require('net');
var HOST = '127.0.0.1';
var PORT = 9694;
var server = net.createServer()
server.listen(PORT, HOST)
server.on('listening', function () {
var addr = server.address() //获取服务器地址，必须在listening事件之后
console.log('Server listening on ' + addr.address + ':' + addr.port);
})
server.on('connection', function (socket) {
console.log('CONNECTED: ' + socket.remoteAddress + ':' + socket.remotePort);
socket.on('data', function (data) {
console.log(data.toString());
socket.write('server write: this is server')
})
socket.on('close', function () {
console.log('CLOSED: ' + socket.remoteAddress + ' ' + socket.remotePort);
server.close();
})
})
server.on('error', function (err) {
console.log('Error occurred: ' + err.message);
})
server.on('close', function () {
console.log('server is closed');
})
获得当前服务器连接数
server.getConnections(function (err, count) {
console.log(count);
})
套接字地址
//套接字绑定的IP地址,端口
socket.localAddress
socket.localPort
socket.address() //与server.address()相同
//远程地址
socket.remoteAddress
socket.remotePort
//套接字接受和发送数据的字节长度
socket.on('data', function (data) {
console.log(socket.bytesRead); //
console.log(data.toString());
socket.write('server write: this is server')
console.log(socket.bytesWritten); //
})
控制套接字数据流
var bSockData = true
server.on('connection', function (socket) {
if(bSockData) {
sock.resume(); //暂停data事件
bSockData = false
} else {
socket.pause(); //继续data事件
bSockData = true
}
socket.on('data', function (data) {})
socket.on('close', function () {})
})
创建UDP服务器客户端
- 创建
socket使用参数udp4/udp6，分别对应Ipv4/Ipv6，前者使用更多
-
UDP数据报发送给服务器后，服务器一般不能回写，因为该协议就是为例快速发送数据包
//server.js
var dgram = require('dgram')
var HOST = '127.0.0.1'
var PORT = 12345;
//创建一个udp4类型的数据报套接字
var server = dgram.createSocket('udp4')
server.on('listening', function () {
var address = server.address();
console.log('UDP Server listening on ' + address.address + ":" + address.port);
})
server.on('message', function (message, remote) {
console.log('UDP Server received from ' + remote.address + ':' + remote.port);
console.log('-' + message);
server.close()
})
server.on('error', function (err) {
console.log('server error: ' + err.stack);
server.close()
})
server.on('close', function () {
console.log('server closed');
})
//绑定主机和端口
server.bind(PORT, HOST)
//client.js
var dgram = require('dgram')
var HOST = '127.0.0.1'
var PORT = 12345;
var message = new Buffer('UDO Client to server');
var client = dgram.createSocket('udp4')
client.send(message, 0, message.length, PORT, HOST,
function (err, bytes) {
if(err) throw err;
console.log('client send to: ' + HOST + ":" + PORT);
console.log('-' + bytes);
client.close();
})
client.on('close', function () {
console.log('client closed');
})
UDP广播服务
-
UDP广播和单播的不同就是通信IP地址不同，广播使用255.255.255.255发送到同一广播上的每个主机
- 广播不会被路由器转发
//server.js
.....
//由于接受客户端广播数据报，仅仅绑定端口号
server.bind(PORT)
//client.js
var HOST = '255.255.255.255'
.....
client.bind(function () {
client.setBroadcast(true) //广播
})
简单的聊天应用
var net = require('net')
var HOST = '127.0.0.1'
var PORT = 6688
var clientList = []
var server = net.createServer();
server.on('connection', function(client) {
clientList.push(client);
client.name = client.remoteAddress + ":" + client.remotePort
broadcast('him ' + client.name + ' join in!\r\n', client)
client.write('hi, ' + client.name + '!\r\n')
client.on('data', function (data) {
broadcast(client.name + ' say:' + data + '\r\n', client)
})
client.on('end', function () {
broadcast('hi,' + client.name + ' quit!\r\n', client)
clientList.splice(clientList.indexOf(client), 1)
})
})
function broadcast(message, client) {
var cleanup = [];
for (var i = 0, len = clientList.length; i < len; i++) {
var o_client = clientList[i]
if(client !== o_client) {
if(o_client.writable) {
o_client.write(message)
} else {
cleanup.push(o_client)
o_client.destroy()
}
}
}
for (var i = 0; i < cleanup.length; i++) {
clientList.splice(clientList.indexOf(cleanup[i]), 1)
}
}
server.listen(PORT, HOST)
