NodeJs以流的形式写入文件

var fs = require("fs");
var data = "http://www.cewan.la phoenixframework自动化平台";
var writerStream = fs.createWriteStream('output.txt');
writerStream.write(data,"UTF-8");
writerStream.end();
writerStream.on('finish', function() {
console.log("写入完成");
});
writerStream.on('error', function(err) {
console.log(err.stack);
});
console.log("execute end...");