resolve JSONException duplicate keys
JSon object, like any other object, can not have two attribute with same name. That's illegal in the same way as having same key twice in a map.
JSONObject would throw an exception if you have two keys with same name in one object. You may want to alter your object so that keys are not repeated under same object. Probably consider nickname as an array.
You need to paste the JSON object in the question.
If you really need this functionality, roll back to gson 1.6. Duplicate keys are allowed in that version.
You can make use of the Jackson library to parse JSON. I'd problems doing the same task as you with org.json's package, but I turned to Jackson and I solved it: http://wiki.fasterxml.com/JacksonHome