Question

I am sendng json data to another jsp page – for testing really.

You enter a JSON formatted string in a text field on my jsp from. I submit this through a form request, handled by jquery processing. It is sent to a receiver JSP. I am using the following code to do this.

Before I send it I get the data using:

jsonData = $form.find( 'textarea[name="jsonData"]' ).val();

I then do:

var parsedJsonObject = $.parseJSON(jsonData);

This is my send code:

$.ajax({  
    type:       "POST",  
    url:        "receiver.jsp",  
    data:       "jsonData=" + parsedJsonObject, // This is an object, created using parseJSON
    success:    function(data, textStatus, jqXHR) {  
                    alert('Success : ' + data);  
                    alert('textStatus : ' + textStatus);  
                    alert('jqXHR : ' + jqXHR);  
                    var jsonJqXHR = JSON.stringify(jqXHR); 
                    alert('jsonJqXHR : ' + jsonJqXHR);  
    },  
    error:function (xhr, ajaxOptions, thrownError){  
        alert('Error xhr : ' + xhr.status);  
        alert('Error thrown error: ' + thrownError);  
    }, 
    //complete: alert('complete'), 
    dataType:   "text" // xml, json, script, text, html                         
}); 

In my JSP, I do a:

String jsonData = request.getParameter("jsonData");
System.out.println("jsonData : " + jsonData);

This returns a output of: json : “[object Object]”

How do I deserialize it? I have done some things with gson, but when I have tried:

Gson gson = new Gson();
String json = gson.toJson(obj);
System.out.println("json = " + json); // I still get an output of: json = "[object Object]"
gson.fromJson(json, MyClass.class); 

I get an error:

servlet jsp threw exception: com.google.gson.JsonParseException: Expecting object found: "[object Object]"

Can anyone help please on the way I need to get this data out of the object?

Answer 1

In your AJAX call, data: "jsonData=" + parsedJsonObject doesn’t do what you intend:

It just gives you a string like [object Object], not the JSON representation you’re looking for.

Use data: "jsonData=" + JSON.stringify(parsedJsonObject) or some jQuery equivalent.