nodejs practical example abbreviation restoration_javascript skills

The idea is very simple:
1. httpserver gets the url that needs to be restored;
2. Use httpclient to recursively request this url until http status not in (302, 301) is found.
3. Return to the restored original url.

Okay, the code is as follows:

Copy the code The code is as follows:

var net = require('net'),
http = require('http'),
url = require('url'),
fs = require('fs');
var DEFAULT_PORTS = {
'http:': 80,
'https:': 443
};
var INDEX_TPL = fs.readFileSync('index.html');
function _write( str, res, content_type) {
if(res.jsonp_cb) {
str = res.jsonp_cb '("' str '")';
}
res.writeHead(200, {
'Content-Length': str.length,
'Content-Type': content_type || 'text/plain'
});
res.end(str);
};
function expand(short_url, res) {
var info = url.parse(short_url);
// console.log('info: ' JSON.stringify(info));
if( info.protocol != 'http:') { // Unable to request https url?
_write(short_url, res);
return;
}
var client = http.createClient(info. port || DEFAULT_PORTS[info.protocol], info.hostname);
var path = info.pathname || '/';
if(info.search) {
path = info.search;
}
var headers = {
host: info.hostname,
'User-Agent': 'NodejsSpider/1.0'
};
var request = client.request('GET ', path, headers);
request.end();
request.on('response', function (response) {
if(response.statusCode == 302 || response.statusCode == 301) {
expand(response.headers.location, res);
} else {
_write(short_url, res);
}
});
};
//expand('http://sinaurl.cn/hbMUII');
// http service
http.createServer(function(req, res){
if(req.url.indexOf( '/api?') == 0) {
var params = url.parse(req.url, true);
if(params.query && params.query.u) {
if(params .query.cb) { // Support jsonp cross-domain request
res.jsonp_cb = params.query.cb;
}
expand(params.query.u, res);
} else {
_write('', res);
}
} else {
_write(INDEX_TPL, res, 'text/html');
}
}).listen(1235 );
process.on('uncaughtException', function (err) {
console.log('Caught exception: ' err);
});

Start you Web server:
$ node urlexpand.js
Open the browser to access directly:
http://127.0.0.1:1235/api?u=http://is.gd/imWyT
Or visit my test server:
http://yongwo.de:1235/api?u=http://is.gd/imWyT&cb=foo