我正在尝试按照http://www.gianlucaguarini.com/blog/push-notification-server-streaming-on-a-mysql-database/上的'教程'来习惯node和node + mysql。虽然使用完全相同的代码但它会引发错误:
C:\node\testproject>node index.js
info - socket.io started
{ [Error: connect ECONNREFUSED]
code: 'ECONNREFUSED',
errno: 'ECONNREFUSED',
syscall: 'connect',
fatal: true }
我正在使用usbwebserver,其中我在端口8080上创建了一个数据库,同时代码正在监听8000.所以我尝试将其更改为8000但无效。这样做的错误略有不同:
C:\node\testproject>node index.js
info - socket.io started
warn - error raised: Error: listen EADDRINUSE
{ [Error: connect ECONNREFUSED]
code: 'ECONNREFUSED',
errno: 'ECONNREFUSED',
syscall: 'connect',
fatal: true }
我使用与上述教程完全相同的代码。但在此参考是:
var app = require('http').createServer(handler),
io = require('socket.io').listen(app),
fs = require('fs'),
mysql = require('mysql'),
connectionsArray = [],
connection = mysql.createConnection({
host : 'localhost',
user : 'root',
password : 'usbw',
database : 'nodejs'
}),
POLLING_INTERVAL = 3000,
pollingTimer;
// If there is an error connecting to the database
connection.connect(function(err) {
// connected! (unless `err` is set)
console.log( err );
});
// creating the server ( localhost:8000 )
app.listen(8000);
// on server started we can load our client.html page
function handler ( req, res ) {
fs.readFile( __dirname + '/client.html' , function ( err, data ) {
if ( err ) {
console.log( err );
res.writeHead(500);
return res.end( 'Error loading client.html' );
}
res.writeHead( 200 );
res.end( data );
});
}
/*
*
* HERE IT IS THE COOL PART
* This function loops on itself since there are sockets connected to the page
* sending the result of the database query after a constant interval
*
*/
var pollingLoop = function () {
// Doing the database query
var query = connection.query('SELECT * FROM users'),
users = []; // this array will contain the result of our db query
// setting the query listeners
query
.on('error', function(err) {
// Handle error, and 'end' event will be emitted after this as well
console.log( err );
updateSockets( err );
})
.on('result', function( user ) {
// it fills our array looping on each user row inside the db
users.push( user );
})
.on('end',function(){
// loop on itself only if there are sockets still connected
if(connectionsArray.length) {
pollingTimer = setTimeout( pollingLoop, POLLING_INTERVAL );
updateSockets({users:users});
}
});
};
// creating a new websocket to keep the content updated without any AJAX request
io.sockets.on( 'connection', function ( socket ) {
console.log('Number of connections:' + connectionsArray.length);
// starting the loop only if at least there is one user connected
if (!connectionsArray.length) {
pollingLoop();
}
socket.on('disconnect', function () {
var socketIndex = connectionsArray.indexOf( socket );
console.log('socket = ' + socketIndex + ' disconnected');
if (socketIndex >= 0) {
connectionsArray.splice( socketIndex, 1 );
}
});
console.log( 'A new socket is connected!' );
connectionsArray.push( socket );
});
var updateSockets = function ( data ) {
// adding the time of the last update
data.time = new Date();
// sending new data to all the sockets connected
connectionsArray.forEach(function( tmpSocket ){
tmpSocket.volatile.emit( 'notification' , data );
});
};
提前致谢!