ajax 响应错误（XML 解析错误：找不到元素位置：moz-nullprincipal）

Question

i am unable to get the response from ajax. please guide me how to resolve this error, i am getting successful data return from the server i have checked it in fiddle web debugger and still ajax is showing error. XML Parsing Error: no element found Location: moz-nullprincipal:{6b0a1ac2-50ab-4053-9f71-8ae49202288d} Line Number 1, Column 1:

            $j.ajax({

            type:"POST",
            url:'http://www.w3schools.com/webservices/tempconvert.asmx/CelsiusToFahrenheit',
            data: 'Celsius=12',
            crossDomain:true,
            async: false,
            success:function(response)
            {
                alert("Success Full Done"+response.string);
            },
            beforeSend: function( xhr ) {
 xhr.overrideMimeType( 'text/plain; charset=UTF-8' );
}

        });

Answer 1

I've this problem with request:

$.ajax({
    type: "POST",
    url: ajaxUrl,
    dataType : "json",
    contentType: "application/json",
    data: JSON.stringify(data),
    success: function (data) {
         ...
    }
});

Accept header in request is:

Accept  application/json, text/javascript, */*; q=0.01

Response status is 200, but browser detect error and no success callback called

Fixed by remove dataType : "json":

$.ajax({
    type: "POST",
    url: ajaxUrl,
    contentType: "application/json",
    ...

The only difference that accept header in request changed to:

Accept  */*

But now success callback is called.

Answer 2

Add the "beforeSend" function into your AJAX call to override the acceptable response mime type.

Refer to the jQuery.ajax() documentation: http://api.jquery.com/jquery.ajax/

As of jQuery 1.5.1, the jqXHR object also contains the overrideMimeType() method (it was available in jQuery 1.4.x, as well, but was temporarily removed in jQuery 1.5). The .overrideMimeType() method may be used in the beforeSend() callback function, for example, to modify the response content-type header:

$.ajax({
  url: "http://fiddle.jshell.net/favicon.png",
  beforeSend: function( xhr ) {
    xhr.overrideMimeType( "text/plain; charset=x-user-defined" );
  }
})
  .done(function( data ) {
    if ( console && console.log ) {
      console.log( "Sample of data:", data.slice( 0, 100 ) );
    }
  });

And:

Data Types

Different types of response to $.ajax() call are subjected to different kinds of pre-processing before being passed to the success handler. The type of pre-processing depends by default upon the Content-Type of the response, but can be set explicitly using the dataType option. If the dataType option is provided, the Content-Type header of the response will be disregarded.

Answer 3

I had the same problem when I made GET XMLHttpRequest call.

var req = new XMLHttpRequest();
req.open('GET', '/exampleServlet', false);
req.send(null);

It was fixed by setting ContentType on the HttpServletResponse.

 response.setContentType("text/plain");

Answer 4

This error may be caused due to two reason. One is when getting no response from java backend and other is when their is no @ResponseBody in java Controller method.

Answer 5

I added ContentType to ResponseEntity and problem solved. Try to add a valid ContentType to your controller response:

ResponseEntity.ok().contentType(MediaType.TEXT_PLAIN).build();

Answer 6

I just ran into the same problem with a simple request:

$.ajax({
    type: "POST",
    url: something,
    data: JSON.stringify(data),
    contentType: "application/json"
});

In my case, this was a fire-and-forget scenario - I don't care about the response. To solve it, it was a case of changing the server-side code to correctly return a 204: No content status code, instead of returning 200: OK .

Answer 7

I am going to be straight up with this after some years of experience: your problem may simply be the environment you've chosen to program in. I have two development environments- VS Code and Netbeans- and for some reason which I don't know ajax and other methods work in one and not the other. I do not know why this is, but with VS Code ajax post calls will just not work, but when the EXACT SAME CODE is used in an IDE like the most recent version of NetBeans it works EXACTLY as it is programmed to do. Test your code across MULTIPLE coding environments because it would not surprise me if you were being screwed over with this for HOURS just because of some stupid coding thing that was happening somewhere else like I was. Your code may be FINE, but these errors lead to weird fixes that may not really be fixes but just weird glitch workarounds. Your code is most likely just fine as it is, and this is why I hate when a product as good as VS Code has these glitches because as great as it is it messes with your concept of your ability to program and stalls you from being able to progress healthily along with your progress. No offense to them, but these glitches SUCK...