Node.js/Express.js Ajax 不返回字符串

Question

I am trying to retrieve passwords in the database via the findOne method. Here is my Ajax:

$.ajax(
      {
        type: 'GET',
        url: '/api/passwords/getPassword',
        contentType: 'application/json',
        dataType: "string",
        async: true,
        data: JSON.stringify({
          "user_name": "fun.test.net",
          "target": "Intern",
          "system_type": "Test",
        })
      }).done(function(data) 
      {
        window.ShowPassword(ele, data);
      }).fail(function() 
      {
        console.log("Error - Password Not Found.");
      });
    }

Along with its supporting function, which just swaps a button out for text (the password):

var buttonId = $(ele).attr('id');
      var buttonText = $(this).html();
      $('#' + buttonId).replaceWith("<span>" + "hello" + "</span>");

And here is my GET function:

router.get('/getPassword', async (req, res) =>
{
    let passwords = await Password.findOne(
    {
        user_name: req.body.user_name,
        target: req.body.target,
        system_type: req.body.system_type,
    });

    if (!passwords) return res.status(404).send('Error 404: The password with the given ID was not found.');
    
    res.send(JSON.stringify(passwords.password));
});

Whenever I call this function, it will throw the error:

TypeError: Cannot read property 'password' of null at C:\Users\e0186030\Desktop\code\password_service2.0\routes\passwords.js:20:39

Please let me know what's going on, I'm not too familiar with Ajax. so I suspect that's what it is. But the idea is that the get function will return its password, It works in postman. so I know the call works by itself.

Answer 1

Try setting the JSON.stringify() to its own variable then sending it in the res:

const password = JSON.stringify(passwords.password);

res.send(password);

Your res.send() could be sending the password before it is actually stringified. Which would result in a null value. Hope this helps.