convert from object to Json in java code example

Example 1: Javascript object to JSON string

var person={"first_name":"Tony","last_name":"Hawk","age":31};
var personJSONString=JSON.stringify(person);

Example 2: convert json string to json object in java

try {
     JSONObject jsonObject = new JSONObject("{\"phonetype\":\"N95\",\"cat\":\"WP\"}");
}catch (JSONException err){
     Log.d("Error", err.toString());
}