如何将use()实例应用于除app.use(express.static(“ dist”))所处理的路由之外的所有路由?

时间:2018-11-16 10:01:27

标签: node.js express jwt

我想我已经在编写过程中解决了这个问题,基本上解决的方法是:

  

将静态文件处理程序移至use()的另一个实例上方

尽管可以肯定这是一种可接受的方法,但在类似情况下可能会帮助其他人。

期望的行为

use()实例应用于除以下处理的路由之外的所有路由:

app.use(express.static("dist")); 

实际行为

use()应用于所有路线,包括由以下路线处理的路线:

app.use(express.static("dist")); 

场景

为了保护对API的访问,我使用的是此Lynda.com教程中描述的模型:

Node.js: Securing RESTful APIs

在伪代码中,该模型实质上包括:

  • 全局use()实例,用于检查是否已发送jwt令牌
  • 如果已发送令牌,则验证令牌
  • 如果验证失败或未发送令牌,它将req.user属性设置为undefined
  • 否则,如果验证成功,它将req.user属性设置为解码的jwt值
  • 随后的中间件根据req.user的值执行条件行为

此模型对于所有意图和目的均适用。

但是,我最近添加了一些控制台日志记录,可以看到两者都在进行验证:

  • api请求(期望的行为)
  • 通过app.use(express.static("dist")) per this convention投放的静态文件(异常行为)

问题

如何将验证use()实例应用于除app.use(express.static("dist"))处理的路由之外的所有路由。

我尝试过的事情

我认为我已通过将代码2下方的代码部分1移至此位置来解决此问题。

// 01.  verification use() called on all requests

app.use((req, res, next) => {

    // if jwt authorisation has been sent in headers, verify it
    if (req.headers && req.headers.authorization && req.headers.authorization.split(' ')[0] === 'JWT') {

        console.log("jwt verification sent, verifying...");

        try {
            // this is synchronous as it has no callback
            req.user = jsonwebtoken.verify(req.headers.authorization.split(' ')[1], 'RESTFULAPIs');
            console.log("jwt verified, will return decoded value");
        } catch (err) {
            req.user = undefined;
            console.log("jwt verification failed, user will remain undefined: " + err);
        }

        // move to the next piece of middleware
        next();

    }
    // if jwt authorisation has not been sent in headers
    else {
        console.log("jwt verification not sent, leaving user as undefined");
        console.log(req.originalUrl);
        req.user = undefined;
        // move to the next piece of middleware
        next();
    }
});


// 02.  use() for serving static files
app.use(express.static("dist"));


// 03.  middleware to check if login has been verified
const api_login_required = (req, res, next) => {

    // if token verification was successful and the user property exists
    if (req.user) {
        // move to the next piece of middleware
        next();
    }
    // otherwise, return unauthorised user message
    else {
        res.json({ verification: 0 });
    }

}


// 04.  middleware called in route handlers
app.route("/api/:api_version/users/private_data")
    .get(api_login_required, api_users_private_data_get)
    .post(api_login_required, api_users_private_data_post);

1 个答案:

答案 0 :(得分:0)

中间件始终控制他们编写的顺序,从“开始”到“按钮”。喜欢

if (example 1)code like 
app.use((req,res, next)=>{// middleware 1; next()} )
app.get('/rot1', (req, res)=> res.status(200).send('route 1'));
app.get('/rot2', (req, res)=> res.status(200).send('route 2'));

In this case, middleware appears in both route1, route because of middleware set at the top of the route.

If (example 2)code like
app.use((req,res, next)=>{// middleware 1; next()} )
app.get('/rot1', (req, res)=> res.status(200).send('route 1'));
app.use((req,res, next)=>{// middleware 2; next()} )
app.get('/rot2', (req, res)=> res.status(200).send('route 2')); 

Here middleware1 applied in both route1 and route 2
But middleware2 applied only on route2.

But you can also define specific middleware for each route
function middleware1(req, res, next){
    next();
}
function middleware2(req, res, next){
    next();
}
app.get('/rot1', middleware1, (req, res)=> res.status(200).send('route 1'));
app.get('/rot2', middleware2, (req, res)=> res.status(200).send('route 2')); 

Here middleware1 only applied on route1 and middleware2 only applied on route2.

也许上面的解释对您有帮助!