Ajax error when running jQuery getJSON

Question

I'm running this getJSON async call in jQuery to get the data back into and then out of my Java code. For whatever reason I continually get the error:

"Ajax Error: Error invoking generateSearchQuery([object Object])"

I've debugged both the jQuery and the Java code. The Java code receives the JSON data, processes it, and writes it back without a problem. The jQuery code kicks the error when it gets into the internal getJson method and tries if(json.successful) .

The response is: {"error":{"message":"","title":"Error Generating Search Query"},"data":[Ljava.lang.String;@1e40c9f,"successful":"successful"}

I've been working on this async call for a few days now, but still can't get it working. Any ideas?

jQuery function:

generate : function(){

    getJson(
        Search.guid,
        "generateSearchQuery",
        {
            "data": [
                "val0",
                "val1",
                "val2",
                "val3",
                "val4"
            ]
        }, function(json) {
            Search.data = $.parseJSON(json.data);

            $.each(Search.data, function(k, v){
                $('#searchQuery').append(v + "\n");
            });
        });
},

Java function:

    @AsyncService(name = "generateSearchQuery", permission = "")
    public void generateSearchQuery(HttpServletRequest req, HttpServletResponse res) {
        res.setHeader("Cache-Control", "no-cache");
        JSONResult result = new JSONResult("Error Generating Search Query");

        String[] arr = req.getParameterValues("data[]");

        for(int i = 0; i< arr.length; i++){
            arr[i] = "success"+i+"!";
        }

        result.put("data", arr);

        try {
            res.getWriter().print(result);
        } catch (IOException e) {
            // whatever
        }
    }
}

getJson:

function getJson(guid, service, parms, callback) {
    beginWork();
    $
            .ajax( {
                url : document.URL,
                type : 'GET',
                data : parms,
                cache : 'false',
                dataType : 'json',
                headers : {
                    'framework-guid' : guid,
                    'async-service' : service
                },
                success : function(json) {
                    endWork();
                    if (json.successful) {
                        callback(json);
                    } else {
                        error(json.error && json.error.title ? json.error.title
                                : 'No Title Provided', json.error
                                && json.error.message ? json.error.message
                                : 'No message provided for service ' + service);
                    }
                },
                error : function(jqXHR, textStatus, errorThrown) {
                    endWork();
                    error('Ajax Error', 'Error invoking ' + service + '('
                            + parms + ')');
                }
            });
}

Answer 1

It seems that the content of the response from server wasn't json format. Because you specify the type of response of $.ajax as json, so you need to convert object result to json. You can use google gson http://code.google.com/p/google-gson/ , and do something like the followings.

Gson gson = new Gson();
res.getWriter().print(gson.toJson(result));

And in getJson, you should make the following changes.

//before
Search.data = $.parseJSON(json.data);
//after
Search.data = json.data;

Answer 2

The response doesn't seam to be valid!

I checked it, you have an invalid label there Ljava.lang.String;@1e40c9f , the error i get when parsing your code is:

SyntaxError: invalid label