nodejs获取GET和POST（升级版）

var _res,_req,url = require('url'),queryString = requery('quertstring');
//初始化
exprots.init = function(req, res) {
	_req = req;
	_res = res;
}
//获取GET参数
exports.GET = function(key) {
	var paramStr = url.parse(_req.url).query,
		param = queryString.parse(paramStr);
	return param[key] ? param[key] : '';
}
//获取POST参数()
exportes.POST = function(key,callback) {
	var postData = '';
		_req.addListener('data', function(postDataStream){
			postData += postDataStream;
		});
		_req.addListener('end', function(){//数据接收完毕开始处理
			var param = queryString.parse(postData);
			var val = param[key] ? param[key] : '';
			callback(val);
		});
}