Nodejs 之 Express 框架实战

准备

• 安装并新建项目

npm install express --save
express -e node 

新建express.js 文件

    var express = require('express');
    var app = express();
    
    
    /* 支持模板文件 */
    var path = require('path');
    app.set('views', path.join(__dirname, 'views'));
    app.set('view engine', 'ejs');
    
    
    /* fs  文件模块 */
    var fs = require("fs");
    
    /* cookie-parser  cookie模块 */
    var cookieParser = require('cookie-parser')
    
    /*post表单专用*/
    var bodyParser = require('body-parser');
    // 创建 application/x-www-form-urlencoded 编码解析
    var urlencodedParser = bodyParser.urlencoded({ extended: false });
    
    
    
    /*上传专用
     * npm install multer --save  安装
     **/
    
    var multer  = require('multer');
    
    app.use(express.static('public'));
    app.use(bodyParser.urlencoded({ extended: false }));
    app.use(multer({ dest: '/tmp/'}).array('image'));
    
    /*使用cookie*/
    app.use(cookieParser())
    
    /*访问静态文件*/
    app.use(express.static('public'));

路由重写

路由重写

// http://localhost:8081
app.get('/', function (req, res) {
    console.log("Cookies: ", req.cookies);
    res.send('Hello , TK !');
})

// http://localhost:8081/about
app.get('/about', function (req, res) {
    var data ={name:'TK',age:'26'}; //赋值模版变量
    res.render('index', data);
})

// http://localhost:8080/contact
app.get('/contact', function (req, res) {
    res.send('联系我们');
})

// http://localhost:8080/detail/1.html
app.get('/detail/*.html', function(req, res) {
    console.log("/*.html GET 请求");
    res.send('伪静态');
})

// 调用index.html 文件
app.get('/index.html', function (req, res) {
    res.sendFile( __dirname + "/" + "index.html" );
})

• 模版调用

// 用户列表
app.get('/ltpl', function (req, res) {
    res.render('list', {
        title: 'List',
        items: ['A', 'B', 'C', 'D', 'E', 'F']
    });
})

调用views/list.ejs

表单/上传处理

• post提交

/*post表单处理*/

// 接收post提交
app.post('/post_form_url', urlencodedParser, function (req, res) {

    // 输出 JSON 格式
    response = {
        salary:req.body.salary,
        year:req.body.year
    };
    console.log(response);
    res.end(JSON.stringify(response));
})

• get提交

/*get表单处理*/

// 接收get提交
app.get('/get_form_url', function (req, res) {

    // 输出 JSON 格式
    response = {
        name:req.query.name,
        age:req.query.age
    };
    console.log(response);
    res.end(JSON.stringify(response));
})

• 文件上传

/*上传文件处理*/
app.post('/file_upload', function (req, res) {

    console.log(req.files[0]);  // 上传的文件信息

    var des_file = __dirname + "/" + req.files[0].originalname;
    fs.readFile( req.files[0].path, function (err, data) {
        fs.writeFile(des_file, data, function (err) {
            if( err ){
                console.log( err );
            }else{
                response = {
                    message:'File uploaded successfully',
                    filename:req.files[0].originalname
                };
            }
            console.log( response );
            res.end( JSON.stringify( response ) );
        });
    });
})

RESTful Web Services

• json 数据

 {
  "user1" : {
    "name" : "tk",
    "password" : "nopass.8",
    "profession" : "teacher",
    "id": 1
  },
  "user2" : {
    "name" : "smudge",
    "password" : "nopass.8",
    "profession" : "librarian",
    "id": 2
  },
  "user3" : {
    "name" : "julylovin",
    "password" : "nopass.8",
    "profession" : "clerk",
    "id": 3
  }
 }

• 添加的新用户json数据

var user = {
    "user4" : {
        "name" : "mohit",
        "password" : "password4",
        "profession" : "teacher",
        "id": 4
    }
}

app.get('/addUser', function (req, res) {
    // 读取已存在的数据
    fs.readFile( __dirname + "/" + "users.json", 'utf8', function (err, data) {
        data = JSON.parse( data );
        data["user4"] = user["user4"];
        console.log( data );
        res.end( JSON.stringify(data));
    });
})

• 显示用户详情

app.get('/detail/:id', function (req, res) {

    fs.readFile( __dirname + "/" + "users.json", 'utf8', function (err, data) {
        data = JSON.parse( data );
        var user = data["user" + req.params.id]
        console.log( user );
        res.end( JSON.stringify(user));
    });
})

• 删除用户

app.get('/delete/:id', function (req, res) {
    // First read existing users.
    fs.readFile( __dirname + "/" + "users.json", 'utf8', function (err, data) {
        data = JSON.parse( data );
        delete data["user" + req.params.id];

        console.log( data );
        res.end( JSON.stringify(data));
    });
})

Mysql数据库操作

• 安装数据库模块

 npm install mysql

• 数据库连接

var mysql      = require('mysql');
var connection = mysql.createConnection({
    host     : 'localhost',
    user     : 'root',
    password : '',
    database : 'b2bplus',
});

connection.connect();

• select 查询

connection.query('SELECT * from cs_user limit 10', function(err, rows, fields) {
     if (err) throw err;
    console.log('data: ',JSON.stringify( rows ));
});

• update 更新

var username = 'Smudge';
connection.query('update cs_user set username = "'+username+'" where user_id = 24', 
function(err,result) {
    if (err) throw err;
    console.log("修改数据成功");
});

• insert 插入

var insert_sql =  'insert into cs_user (sid,username) values(1002,"Smudge")';
connection.query(insert_sql, function(err,result) {
    if (err) throw err;
    console.log("插入数据成功");
});

• delete 删除

connection.query('delete from cs_user where username= "Smudge"', function(err,result){
    if (err) throw err;
    console.log("删除数据成功");
});

监听端口

var server = app.listen(8080, function () {

    var host = server.address().address
    var port = server.address().port

    console.log("应用实例，访问地址为 http://%s:%s", host, port)

})