How to search/find In JSON with java

Question

I have a below JSON string from the below i want to find/search criteria in JSON String.

1). To find the Number of keys present. 2). To get the values of given key(

Answer 1

I would try the following library

https://github.com/jayway/JsonPath

http://jsonpath.herokuapp.com/?path=%24.store.book[*]

gives you all books