JSON stringify - Need to convert JSON to string have escape characters in java

{ "name": "John", 
"email": "john.doe@gmail.com", 
"age": 29, "phone" : 5168161922, 
"city" : "NewYork", 
"hasCreditCard": false }

Need to convert this JSON to string with with escape sequences. JSON.toString(); doesn't work - It doesnt add escape characters("\")