Cordova android plugin unable to update JSON object - json

Question

i have developed a cordova plugin for optical character recognition. I send image to android and the image processing part is done by the plugin and after processing the plugin returns the JSON object back to Cordova. The plugin is working fine for the first time only the data is received correctly but when i tried to process an image for second time the data returned by the plugin is correct but on cordova side the Json object is not updated it shows previous data.
try {
if (ACTION.equals(action))
{
Log.d("action name", action);
Log.d("json object", args.getString(0));
//JSONObject arg_object = args.getJSONObject(0);
this.callbackContext = callbackContext;
if(ACTION_CAMERA.equals(args.getString(0))){
Log.d("action name", "camera");
cordova.getThreadPool().execute(new Runnable() {
public void run() {
camera();
callbackContext.sendPluginResult(new PluginResult(PluginResult.Status.OK, json)); // Thread-safe.
}
});
}
/*
* sending the JSON object containing OCR results and BASE64 encoded string to javaScript
*/
//callbackContext.sendPluginResult(new PluginResult(PluginResult.Status.OK, json));
result = true;
Log.d("after results", "after results");
}
else{
callbackContext.error("Invalid action");
result = false;
}
return result;
}
catch(Exception e)
{
System.err.println("Exception: " + e.getMessage());
callbackContext.error(e.getMessage());
return false;
}
}
and my cordova code is
function onPhotoURISuccess(obj) {
alert(obj['all']);
// clear image div contents
$("#base64Image").empty();
$("#base64Image").attr('src', '');
var image = new Image();
image.src = 'data:image/png;base64,' + obj['imageBase64'];
$("#base64Image").append(image);
$('#base64Image').width();
}
// A button will call this function
function capturePhoto() {
var success = function(message) {
onPhotoURISuccess(message);
}
var failure = function() {
alert("Error calling OCR 1 Plugin");
}
OCRPlugin.greet("camera", success, failure);
}