How can I serialize a Java object to a escaped JSON string?
{

"content":"{"field1":123, "field2":1, "field3":0, "field4":{"sub1":"abc", "sub2":"xyz"}}n
{"field1":234, "field2":9, "field3":1, "field4":{"sub1":"xyz", "sub2":"abc"}}"

}

Gson gson = new GsonBuilder().setPrettyPrinting().create();

{
  "content": [
    "{"field1":123, "field2":1, "field3":0, "field4":{"sub1":"abc", "sub2":"xyz"}}",
    "{"field1":234, "field2":9, "field3":1, "field4":{"sub1":"xyz", "sub2":"abc"}}"
  ]
}

String jsonStrData = " ....... ";
JSONObject jsonObj = JSONObject.fromObject(jsonStrData);
System.out.println(jsonObj);