javascript - Node.js (Openshift) 快速响应不起作用

Question

我正在使用 OpenShift 和 Node.js我试图获得每个结果的平均评分，但我不能即使控制台报告正确，也能得到响应。我在控制台中输入 3.9454323 ，但是当我 git localhost:3002/getM/1 时，响应为空白。

app.get('/getM/:movieId', function(request,response) {
  var movieId = request.params.movieId;
  var connection = mysql.createConnection({
    host: process.env.OPENSHIFT_MYSQL_DB_HOST || 'localhost',
    user: process.env.OPENSHIFT_MYSQL_DB_USERNAME || 'root',
    password: process.env.OPENSHIFT_MYSQL_DB_PASSWORD || '',
    port: process.env.OPENSHIFT_MYSQL_DB_PORT || '3306',
    database: 'test'
  });
  connection.connect(function (err) {
    if (err) {
      console.error('error connecting: ' + err.stack);
      response.send("error connecting to database");
      return;
    }
    console.log('connected as id ' + connection.threadId);
  });
  connection.query('SELECT * FROM `ratings` WHERE `movieId` = ?',[movieId], function(err, result) {
    if (err) {
      response.send(err);
    }
    var sum = 0;
    result.forEach(function(movie) {
      sum += movie["rating"];
      console.log(sum);
    });
    console.log(sum/result.length);
    response.send(sum/result.length);
  });
});

Answer 1

您正在向 response.send() 传递一个数字参数。以下是明确文档的内容:

res.send([body])

Sends the HTTP response.

The body parameter can be a Buffer object, a String, an object, or an Array.

参见:http://expressjs.com/api.html

试试这个:

response.send( "" + sum/result.length );

编辑:顺便说一句，如果您使用旧版本的express，那么express可能会尝试将数字解释为HTTP状态代码。我不确定 express 将如何处理浮点值，但无论如何，这显然不是您想要的。

Finally when a Number is given without any of the previously mentioned bodies, then a response body string is assigned for you. For example 200 will respond will the text “OK”, and 404 “Not Found” and so on.

参见:http://expressjs.com/3x/api.html#res.send