node.js 如何使用 ExpressJS 检查 Content-Type？
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How do I check Content-Type using ExpressJS?
提问by JuJoDi
I have a pretty basic RESTful API so far, and my Express app is configured like so:
到目前为止，我有一个非常基本的 RESTful API，我的 Express 应用程序配置如下：
app.configure(function () {
app.use(express.static(__dirname + '/public'));
app.use(express.logger('dev'));
app.use(express.bodyParser());
});
app.post('/api/vehicles', vehicles.addVehicle);
How/where can I add middleware that stops a request from reaching my app.postand app.getif the content type is not application/json?
如何/我在哪里可以添加中间件到达站的请求我app.post和app.get如果内容类型是不是application/json？
The middleware should only stop a request with improper content-type to a url that begins with /api/.
中间件应该只停止对以/api/.
回答by Willie Chalmers III
If you're using Express 4.0 or higher, you can call request.is()on requests from your handlers to filter request content type. For example:
如果您使用 Express 4.0 或更高版本，您可以调用request.is()来自处理程序的请求来过滤请求内容类型。例如：
app.use('/api/', (req, res, next) => {
if (!req.is('application/json')) {
// Send error here
res.send(400);
} else {
// Do logic here
}
});
回答by mscdex
This mounts the middleware at /api/(as a prefix) and checks the content type:
这将中间件挂载在/api/（作为前缀）并检查内容类型：
app.use('/api/', function(req, res, next) {
var contype = req.headers['content-type'];
if (!contype || contype.indexOf('application/json') !== 0)
return res.send(400);
next();
});
回答by Yuriy Nemtsov
As an alternative, you can use the express-ensure-ctypemiddleware:
作为替代方案，您可以使用express-ensure-ctype中间件：
const express = require('express');
const ensureCtype = require('express-ensure-ctype');
const ensureJson = ensureCtype('json');
const app = express();
app.post('/', ensureJson, function (req, res) {
res.json(req.body);
});
app.listen(3000);
回答by xpapazaf
For input validation a good module is express-validator. It provides the middlewares needed to do any kind of check. In your case something like:
对于输入验证，一个很好的模块是express-validator。它提供了进行任何类型检查所需的中间件。在你的情况下是这样的：
const { check, validationResult } = require('express-validator')
app.use('/api/', [
check('content-type').equals('application/json')
], function(req, res, next) {
const errors = validationResult(req);
if (!errors.isEmpty()) {
return res.status(422).json({ errors: errors.array() });
}
next();
});
