SyntaxError:Object.parse(native)上的意外标记u JSON.parse()的NodeJS

Question

我正处于NodeJs的学习阶段,我试图从URL中传递的json中获取参数值.我正在使用body解析器,因为我看到许多堆栈溢出答案使用相同来解析数据.

以下是我通过的网址,

http://localhost:1337/login?json={username:rv,password:password}

我收到下面提到的错误,

SyntaxError: Unexpected token u
at Object.parse (native)
at C:\Users\summer\Desktop\nodejs\practise3.njs:14:17
at Layer.handle [as handle_request] (C:\Users\summer\Desktop\nodejs\node_modules\express\lib\router\layer.js:95:5)
at next (C:\Users\summer\Desktop\nodejs\node_modules\express\lib\router\route.js:131:13)
at Route.dispatch (C:\Users\summer\Desktop\nodejs\node_modules\express\lib\router\route.js:112:3)
at Layer.handle [as handle_request] (C:\Users\summer\Desktop\nodejs\node_modules\express\lib\router\layer.js:95:5)
at C:\Users\summer\Desktop\nodejs\node_modules\express\lib\router\index.js:277:22
at Function.process_params (C:\Users\summer\Desktop\nodejs\node_modules\express\lib\router\index.js:330:12)
at next (C:\Users\summer\Desktop\nodejs\node_modules\express\lib\router\index.js:271:10)
at jsonParser (C:\Users\summer\Desktop\nodejs\node_modules\body-parser\lib\types\json.js:100:40)

代码如下所述,

var express = require('express');
var http = require('http');
var app = express();
var bodyparser = require('body-parser');

app.use(bodyparser.json());

app.get('/login',function(req,res,next){
    var content = '';
    var data = '';
    data = req.query.json;
    content = JSON.parse(data);        //I am getting the error here
    res.writeHead(200,{"Content-type":"text/plain"});
    res.write(data);
    res.end();
});

http.createServer(app).listen(1337);
console.log("Server Started successfully at Port 1337");

注意:阅读完这个问题之后,如果你知道从json数据中收集值的其他选择,请告诉我们.

Answer 1

而不是这个:

data = req.query.json;
content = JSON.parse(data);        //I am getting the error here

试试这个:

data = req.query.json;
var stringify = JSON.stringify(data)
content = JSON.parse(stringify);       

Answer 2

JSON.parse 因为与Javascript不同,JSON要求所有的键名都在引号[0]中,所以你的JSON应该是

{"username":rv,"password":password}

当JSON解析器遇到"用户名"开头的"u"时,会发生错误"Unexpected token u ...",当时它需要一个引号.

[0]在http://json.org上有一个非常易读的JSON规范摘要.