Nodejs处理异常操作示例

本文实例讲述了Nodejs处理异常操作。分享给大家供大家参考，具体如下：

Exception.js

module.exports = {
 expfun: function(flag) {
 if(flag == 0) {
 throw '我是error';
 }
 return "success";
 }
}

optfile.js

//-------------optfile.js-------------------------
var fs = require('fs');
module.exports = {
 readfile: function (path, recall) { //异步执行
 fs.readFile(path, function (err, data) {
 if (err) {
 console.log("异步执行error：" + err);
 recall("文件不存在，异步执行error：" + err);//异步处理异常
 } else {
 //console.log(data.toString());
 recall(data);
 }
 });
 console.log("===异步方法执行完毕===");
 },
 readImg: function (path, res) {
 fs.readFile(path, 'binary', function (err, filedata) {
 if (err) {
 console.log(err);
 return;
 } else {
 console.log("输出文件");
 res.write(filedata, 'binary');
 res.end();
 }
 });
 }
}

router.js

var optfile = require('../model/optfile2.js');
function getRecall(req, res) {
 res.writeHead(200, {
 'Content-Type': 'text/html; charset=utf-8'
 });
 function recall(data) {
 res.write(data);
 res.end(''); //不写则没有http协议尾
 }
 return recall;
}
module.exports = {
 login: function (req, res) {
 recall = getRecall(req, res);
 optfile.readfile('./view/login.html', recall);
 },
 showimg: function (req, res) {
 res.writeHead(200, {
 'Content-Type': 'image/jpeg'
 });
 optfile.readImg("./view/pig.png", res);
 }
}

//-------------n9_exception.js---------------
/*
同步的捕获&&异步的捕获
*/
var http = require('http');
var url = require('url');
var router = require('./model/router');
var exception = require('./model/Exception');
http.createServer(function (request, response) {
 if (request.url !== "/favicon.ico") { //清除第2此访问
 pathname = url.parse(request.url).pathname;
 pathname = pathname.replace(/\//, ''); //替换掉前面的/
 try {
 router[pathname](request, response);
 // data = exception.expfun(0);
 // response.write(data);
 // response.end('');
 } catch (err) {
 console.log('捕获到异常=' + err);
 response.writeHead(200, {
 'Content-Type': 'text/html; charset=utf-8'
 });
 response.write(err.toString());
 response.end('');
 }
 console.log("server执行完毕");
 }
}).listen(8000);
console.log('Server running at http://127.0.0.1:8000/');

希望本文所述对大家nodejs程序设计有所帮助。