Get error on sending JSON from JavaScript to Java

Question

I want to send some data from JavaScript to Java servlet with help of JSON. But I have problem with it.

This is my JavaSript code:

var myData = {"someNumber":34,"someDate":"May 22, 2014 12:00:00 AM","expiryDate":"May 29, 2014 12:00:00 AM","anotherNumber":3,"customerNumber":56,"name":"John Dow","type":"notype","someSize":"XXL","noMonth":11,"notes":"some notes here","colour":"Black"};
$.ajax({
            url :           "customerAdd",
            type:           "get",
            data:           {"myData" : JSON.stringify(myData)},
            contentType:    "application/json; charset=utf-8",
            dataType:       "json",
            async:          false,
            success:        function(msg) {
                alert(msg);
            },
            error:          function(jqXHR, textStatus, errorThrown) {
                console.log("jqXHR: " + textStatus);
                console.log("textStatus: " + textStatus);
                console.log("errorThrown: " + errorThrown);
            }
        });

This is my Java code:

 public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException{    
        Gson gson = new GsonBuilder().create();
        Customer customer = gson.fromJson(request.getParameter("myData"), Customer.class);
        System.out.println(customer.toString());
    }

In result I get an error in JavaScript:

"textStatus: parsererror"
"errorThrown: SyntaxError: JSON.parse: unexpected end of data at line 1 column 1 of the JSON data"

What's wrong with my code?

P.S. I create myData in JavaScript by this way:

var myData = {  
                someNumber:    + $("#someNumber").val(),
                someDate:       $("#someDate").val(),
                expiryDate:     $("#expiryDate").val(),
                anotherNumber:      + $("#anotherNumber").val(),
                customerNumber: + $("#customerNumber").val(),
                name:           $("#name").val(),
                type:           $("#type").val(),
                someSize:        $("#someSize").val(),
                noMonth:        + $("#noMonth").val(),
                notes:          $("#notes").val(),
                colour:         $("#colour").val() };

Tony · Accepted Answer · 2014-05-22 10:57:04Z

2

Here is a JSON.stringify exemple :

JSON.stringify({x: 5, y: 6}); // '{"x":5,"y":6}'

You should remove the quots on the name of parameters, or could use a javascript object.

You should create your object like that :

var myData = new Object();
mydata.someNumber = $("#someNumber").val();
...

edit :

It's seems your trying to get a response in the ajax call, but your java code doesn't response anything, maybe you may try to debug it. and try to see if the java code is triggered ?

edited May 22, 2014 at 10:57

answered May 22, 2014 at 9:09

Tony

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3 Comments

Valentyn Grygoriev Over a year ago

I've created my object as you suggested but unfortunately I received the same error.

Tony Over a year ago

new edit : you should try to remove the msg attribute in the success function prototype if your java code is triggered

Valentyn Grygoriev Over a year ago

I had removed msg attribute, but it didn't help. My java code doesn't response anything. But java code correctly parse received JSON data and does System.out.println(customer.toString()); without any errors.

Rohan Kumar · Accepted Answer · 2014-05-22 09:16:34Z

1

maybe try

JSON.stringify({ "myData" : myData })

edited May 22, 2014 at 9:16

Rohan Kumar

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answered May 22, 2014 at 9:11

Lee Bee

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10 Comments

Lee Bee Over a year ago

assuming that your myData object is valid I think you should be able to do this : $.ajax({ url : "customerAdd", type: "get", data: JSON.stringify({ "myData": myData } ), etc.

Lee Bee Over a year ago

when you create your myData object some of the values have + and some don't, do you need these ?

Valentyn Grygoriev Over a year ago

I added + to make a numeric values. I have removed + but it didn't help. I received the same error.

Lee Bee Over a year ago

did you try changing data: {"myData" : JSON.stringify(myData)}, to data: JSON.stringify({"myData": myData}),

Valentyn Grygoriev Over a year ago

I changed data to data:JSON.stringify({"myData" : myData}). In result I think GET request became incorrect http://localhost:8080/customerAdd?{%22myData%22:{%22magicNumber%22:%2234%22,%22someDate%22:%22May%2022,...}} and now I receive another error: errorThrown: Internal Server Error.

|

Valentyn Grygoriev · Accepted Answer · 2014-05-22 14:13:07Z

1

I've found my mistake. I shouldn't put

dataType: "json",

attribute in $.ajax, because I don't expect JSON data back from server. I've just removed it.

Thank you Lee Bee and Tony for your advices.

answered May 22, 2014 at 14:13

Valentyn Grygoriev

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Comments

srinivas · Accepted Answer · 2014-06-29 09:43:13Z

0

If the servlet method is not returning any json content to ajax, remove the

dataType: "json", from ajax call in javascript.

answered Jun 29, 2014 at 9:43

srinivas

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