express.js中app.use和app.get的区别 [英] Difference between app.use and app.get in express.js

问题描述

我很喜欢表达和node.js，我无法弄清楚app.use和app.get之间的区别。看来你可以使用他们两个来发送信息。例如：

  app.use（'/'，function（req，res，next）{
 res。 send（'Hello'）; 
 next（）; 
}）; 
  

似乎与以下相同：

  app.get（'/'，function（req，res）{
 res.send（'Hello'）; 
}）; 
  

解决方案

app.use（） 旨在绑定中间件到您的应用程序。 路径是挂载或前缀路径，并限制中间件仅适用于请求的任何路径 开始 。甚至可以用来嵌入另一个应用程序：

  // subapp.js 
 var express = require（'express ）; 
 var app = modules.exports = express（）; 
 // ... 
  

  //服务器.js 
 var express = require（'express'）; 
 var app = express（）; 
 
 app.use（'/ subapp'，require（'./ subapp'））; 
 
 // ... 
  

通过指定 / 作为挂载路径， app.use（）将响应以$开头的任何路径c $ c> / ，这些都是它们，不管使用的是HTTP动词：

• GET /


• PUT / foo


• POST / foo / bar


• 等。

$ b $另一方面，b

app.get（）是Express'应用程序路由，并且用于在请求时使用 GET HTTP动词来匹配和处理特定路由：

• GET /

而且，您的 app.use（）示例的等效路由实际上将是：

  app.all（/ ^ \ /.*/，function（req，res）{
 res.send（'Hello'）; 
}）; 
  

I'm kind of new to express and node.js, and I can't figure out the difference between app.use and app.get. It seems like you can use both of them to send information. For example:

app.use('/',function(req, res,next) {
    res.send('Hello');
    next();
});

seems to be the same as this:

app.get('/', function (req,res) {
   res.send('Hello');
});

解决方案

app.use() is intended for binding middleware to your application. The path is a "mount" or "prefix" path and limits the middleware to only apply to any paths requested that begin with it. It can even be used to embed another application:

// subapp.js
var express = require('express');
var app = modules.exports = express();
// ...

// server.js
var express = require('express');
var app = express();

app.use('/subapp', require('./subapp'));

// ...

By specifying / as a "mount" path, app.use() will respond to any path that starts with /, which are all of them and regardless of HTTP verb used:

• GET /
• PUT /foo
• POST /foo/bar
• etc.

app.get(), on the other hand, is part of Express' application routing and is intended for matching and handling a specific route when requested with the GET HTTP verb:

• GET /

And, the equivalent routing for your example of app.use() would actually be:

app.all(/^\/.*/, function (req, res) {
    res.send('Hello');
});

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