express route的用法

express route的用法

1. 直接使用app.METHOD

const express = require('express');
const app = express();

app.get('/hello', (req, res) => {
  console.log('in get');
  res.send('Hello World');
});

app.listen(8080, () => {
  console.log(`Server running at: http://localhost:8080/`);
});

2. 使用router

const express = require('express');
const app = express();
const router = express.Router()

router.get('/hello', (req, res) => {
  console.log('in get');
  res.send('Hello World');
});

app.use('/', router);

app.listen(8080, () => {
  console.log(`Server running at: http://localhost:8080/`);
});

这里需要注意的是'app.use('/', router)'使用根目录，然后在router里面是根据此根目录的相对目录的，所以客户端访问地址是：localhost:8080/hello，而如果使用app.use('/hello', router);，则客户端访问地址是：localhost:8080/hello/hello

通常我们会把router放到一个独立的模块里：

$ cat router.js
const express = require('express');
const router = express.Router()

router.get('/hello', (req, res) => {
  console.log('in get');
  res.send('Hello World');
});

router.get('/hello2', (req, res) => {
  console.log('in get2');
  res.send('Hello World');
});

module.exports = router

然后在index.js里面调用：

$ cat index.js
const express = require('express');
const app = express();
const router =  require('./router.js');

app.use('/', router);

app.listen(8080, () => {
  console.log(`Server running at: http://localhost:8080/`);
});

客户端可以调用localhost:8080/hello，和localhost:8080/hello2。

3. 是app.route()

const express = require('express');
const app = express();

app.route('/hello')
  .all(function (req, res, next) {
    console.log('in all');
    next()
    // runs for all HTTP verbs first
    // think of it as route specific middleware!
  })
  .get(function (req, res, next) {
    console.log('in get');
    res.send('Hello World');
  })
  .post(function (req, res, next) {
    console.log('in post');
    res.send('Hello World');
  })

app.listen(8080, () => {
  console.log(`Server running at: http://localhost:8080/`);
});

这样的好处是只写一个route如果支持不同的方法。