node + express + mongodb 的问题，能收到请求，但是不能做出相应页面。不知道怎么解决~求大神帮忙，急~~~

Question

node 报错信息如下：（         

Error: Can't set headers after they are sent.

    at ServerResponse.OutgoingMessage.setHeader (_http_outgoing.js:357:11)

    at ServerResponse.header (D:\Hexin\FrontEnd\movie\node_modules\express\lib\response.js:730:10)

    at ServerResponse.send (D:\Hexin\FrontEnd\movie\node_modules\express\lib\response.js:170:12)

    at done (D:\Hexin\FrontEnd\movie\node_modules\express\lib\response.js:967:10)

    at Object.exports.renderFile (D:\Hexin\FrontEnd\movie\node_modules\pug\lib\index.js:422:12)

    at View.exports.__express [as engine] (D:\Hexin\FrontEnd\movie\node_modules\pug\lib\index.js:465:11)

    at View.render (D:\Hexin\FrontEnd\movie\node_modules\express\lib\view.js:128:8)

    at tryRender (D:\Hexin\FrontEnd\movie\node_modules\express\lib\application.js:640:10)

    at EventEmitter.render (D:\Hexin\FrontEnd\movie\node_modules\express\lib\application.js:592:3)

    at ServerResponse.render (D:\Hexin\FrontEnd\movie\node_modules\express\lib\response.js:971:7)

    at D:\Hexin\FrontEnd\movie\app.js:90:9

    at Layer.handle [as handle_request] (D:\Hexin\FrontEnd\movie\node_modules\express\lib\router\layer.js:95:5)

    at next (D:\Hexin\FrontEnd\movie\node_modules\express\lib\router\route.js:137:13)

    at Route.dispatch (D:\Hexin\FrontEnd\movie\node_modules\express\lib\router\route.js:112:3)

    at Layer.handle [as handle_request] (D:\Hexin\FrontEnd\movie\node_modules\express\lib\router\layer.js:95:5)

    at D:\Hexin\FrontEnd\movie\node_modules\express\lib\router\index.js:281:22

GET / 404 76.603 ms - 645

浏览器报错：

路由：

控制：(    

Answer 1

你的express.js有问题。引入router的位置。必须放在错误处理之前，也就是说 ：app.use(bodyParser.urlencoded({extended: false}));    require('../app/routes/news.server.routes')(app);    app.use(function(req, res, next) {    res.status(404);    try {    return res.json('NOT FOUND');    } catch (e) {    console.error('404 set header after sent');    }    });    app.use(function(err, req, res, next) {    if (!err) {    next()    } else {    res.status(500);    try {    return res.json(err.message || '500 SERVER ERROR');    } catch (e) {    console.error('500 set header after sent');    }    }    });    看见加粗的了吗？后面两个错误处理必须放在最后，因为路由匹配规则是从上到下，匹配到了就终止！