JSON.simple

https://howtodoinjava.com/json-simple/json-simple-read-write-json-examples/

JSON.simple is lightweight _JSON processing library _which can be used to read JSON, write JSON file. Produced JSON will be in full compliance with JSON specification (RFC4627).

The JSON-Simple is another open source library which supports JSON parsing and formatting. The good thing about this library is its small size, which is perfect for memory constraint environments like J2ME and Android.

Read more:

http://www.java67.com/2016/10/3-ways-to-convert-string-to-json-object-in-java.html#ixzz5JAhXfxoB