Question

我试图通过jQuery和Ajax发布查询后从我的服务器读取响应。我认为这是因为我尝试使用res.render呈现页面，并在使用res.end从我的数据库接收数据后写出响应。但我不知道如何解决它，因为我是NodeJS express的新手。

这是我的nodejs部分，它接收请求，查询数据库并尝试发送响应：

app.all('/Search', function(req, res) {
    res.render('search');
    var query = req.body.username;
    if (req.body.username)
    {
    db.collection('users').find({username: query}).toArray(function(err, result) {
        if (err) return console.log(err);
        console.log("Request body  = "+req.body.username);
        console.log(result);
        res.writeHead(200, { 'Content-Type': 'application/json' }); 
        res.end(JSON.stringify(data));
    });
    }
});

以下是search.ejs html页面，其中嵌入了jquery：

<!DOCTYPE html>
<html lang="en">
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
    <head>
    <meta charset="UTF-8">
    <title>MY APP</title>
    </head>
    <body>
    <div style="margin: 0 auto;width: 500px;">
        <form id="searchForm" action="/Search" method="post" style="margin: 0 auto; width: 200px; margin-top: 100px;">
        <input id="username" type="text" placeholder="Search" name="username"  style="margin: 20px auto; font-size: 50px;">
        <!-- <input type="file" name="picture"> -->
        <button type="submit"  style="margin: 20px auto; font-size: 50px;">Submit</button>
        </form>
    </div>

    <script type="text/javascript">
     $('#searchForm').on('submit', function (event) {
         console.log("HI");
         event.preventDefault(); // Stop the form from causing a page refresh.
         var data = {
         username: $('#username').val()
         };
         console.log("DATA === "+data);
         $.ajax({
         url: 'http://localhost:3000/Search',
         data: data,
         method: 'POST'
         }).then(function (response) {
         console.log("Response ="+response);
         // Do stuff with the response, like add it to the page dynamically.
             $('body').append(response);
         }).catch(function (err) {
         console.error(err);
         });
     });
    </script>
    </body>
</html>

以下是终端的输出：

Server started at port:3000
Request body  = abc
[ { _id: 5938c2f9453e40053965e9ec,
    username: 'abc',
    specialty: 'dsfsaddfjk',
    address: 'oidjfioa' } ]
/home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb/lib/utils.js:123
    process.nextTick(function() { throw err; });
                                  ^

错误：发送后无法设置标头。

    at ServerResponse.setHeader (_http_outgoing.js:371:11)
    at ServerResponse.writeHead (_http_server.js:183:21)
    at /home/vineet/Desktop/serene-brushlands-55292/app.js:52:10
    at handleCallback (/home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb/lib/utils.js:120:56)
    at /home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb/lib/cursor.js:860:16
    at handleCallback (/home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb-core/lib/cursor.js:171:5)
    at setCursorDeadAndNotified (/home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb-core/lib/cursor.js:505:3)
    at nextFunction (/home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb-core/lib/cursor.js:651:7)
    at Cursor.next [as _next] (/home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb-core/lib/cursor.js:692:3)
    at fetchDocs (/home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb/lib/cursor.js:856:10)
    at /home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb/lib/cursor.js:879:7
    at handleCallback (/home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb-core/lib/cursor.js:171:5)
    at nextFunction (/home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb-core/lib/cursor.js:682:5)
    at /home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb-core/lib/cursor.js:593:7
    at queryCallback (/home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb-core/lib/cursor.js:232:18)
    at /home/vineet/Desktop/serene-brushlands-55292/node_modules/mongodb-core/lib/connection/pool.js:469:18

我在jQuery存根中收到的响应是search.ejs本身的html。请帮忙!!

Answer 1

自己找到答案。将app.all转为app.post并将另一个app.get添加到Search并将渲染移动到它。

Nodejs通过jquery / ajax表示发布查询，在读取响应时无法设置头文件错误

1 个答案: