<!-- https://mvnrepository.com/artifact/com.jayway.jsonpath/json-path -->
<dependency>
    <groupId>com.jayway.jsonpath</groupId>
    <artifactId>json-path</artifactId>
    <version>2.9.0</version>
</dependency>

 testImplementation 'com.jayway.jsonpath:json-path:2.6.0'

$.store.book[0].title

$['store']['book'][0]['title']

{
    "store": {
        "book": [
            {
                "category": "reference",
                "author": "Nigel Rees",
                "title": "Sayings of the Century",
                "price": 8.95
            },
            {
                "category": "fiction",
                "author": "Evelyn Waugh",
                "title": "Sword of Honour",
                "price": 12.99
            },
            {
                "category": "fiction",
                "author": "Herman Melville",
                "title": "Moby Dick",
                "isbn": "0-553-21311-3",
                "price": 8.99
            },
            {
                "category": "fiction",
                "author": "J. R. R. Tolkien",
                "title": "The Lord of the Rings",
                "isbn": "0-395-19395-8",
                "price": 22.99
            }
        ],
        "bicycle": {
            "color": "red",
            "price": 19.95
        }
    },
    "expensive": 10
}

String allBooks = JsonPath.read(jsonString, "$..*").toString();
System.out.println("--------------- All books in the store --------------");
System.out.println(allBooks);

import com.jayway.jsonpath.JsonPath;
public class JsonPath_Demo {

    public static void main(String args[]) {

        String jsonString = new String(Files.readAllBytes(Paths.get("src/test/resources/Payloads/test.json")));

        String allBooks = JsonPath.read(jsonString, "$..*").toString();
        System.out.println("--------------- All books in the store --------------");
        System.out.println(allBooks);
    }
}

 // All bicycles in the store
String allBicycles = JsonPath.read(jsonString, "$..bicycle").toString();
System.out.println("--------------- All bicycles in the store ---------------");
System.out.println(allBicycles);

// The number of books
String noOfBooks = JsonPath.read(jsonString, "$..book.length()").toString();
System.out.println("--------------- The number of books ---------------");
System.out.println(noOfBooks);

// The authors of all books
String authors = JsonPath.read(jsonString, "$.store.book[*].author").toString();
System.out.println("--------------- Author of all Books ---------------");
System.out.println(authors);

// All authors
String allAuthors = JsonPath.read(jsonString, "$..author").toString();
System.out.println("--------------- All Authors ---------------");
System.out.println(allAuthors);

// All details of the store
String store = JsonPath.read(jsonString, "$.store.*").toString();
System.out.println("--------------- All details of the store ---------------");
System.out.println(store);

// Price of store
String storePrice = JsonPath.read(jsonString, "$.store..price").toString();
System.out.println("--------------- price of store ---------------");
System.out.println(storePrice);

// Third book
String thirdBook = JsonPath.read(jsonString, "$..book[2]").toString();
System.out.println("--------------- third book ---------------");
System.out.println(thirdBook);

// first Last Book
String firstLastBook = JsonPath.read(jsonString, "$..book[-1]").toString();
System.out.println("--------------- first Last Book ---------------");
System.out.println(firstLastBook);

// first two Books
String firstTwoBooks = JsonPath.read(jsonString, "$..book[0,1]").toString();
System.out.println("--------------- first Two Books ---------------");
System.out.println(firstTwoBooks);

// books from index 0 (inclusive) until index 2 (exclusive)
String booksRange = JsonPath.read(jsonString, "$..book[:2]").toString();
System.out.println("--------------- books from index 0 (inclusive) until index 2 (exclusive) ---------------");
System.out.println(booksRange);

// All books from index 1 (inclusive) until index 2 (exclusive)
String booksRange1 = JsonPath.read(jsonString, "$..book[1:2]").toString();
System.out.println("------------ All books from index 1 (inclusive) until index 2 (exclusive) -----------");
System.out.println(booksRange1);

// Book number one from tail
String bottomBook = JsonPath.read(jsonString, "$..book[1:]").toString();
System.out.println("--------------- Book number one from tail ---------------");
System.out.println(bottomBook);

// All books in store expensive than 10
String expensiveBook = JsonPath.read(jsonString, "$.store.book[?(@.price > 10)]").toString();
System.out.println("--------------- All books in store costlier than 10 ---------------");
System.out.println(expensiveBook);

// All books in store that are not "expensive"
String notExpensiveBook = JsonPath.read(jsonString, "$..book[?(@.price <= $['expensive'])]").toString();
System.out.println("--------------- All books in store that are not expensive ---------------");
System.out.println(notExpensiveBook);

// All books in store that are equal to price 8.95
String comparePrice = JsonPath.read(jsonString, "$.store.book[?(@.price == 8.95)]").toString();
System.out.println("--------------- All books in store that are not expensive ---------------");
System.out.println(comparePrice);

// All books matching regex (ignore case)
String regxExample = JsonPath.read(jsonString, "$..book[?(@.author =~ /.*REES/i)]").toString();
System.out.println("--------------- All books matching regex (ignore case) ---------------");
System.out.println(regxExample);

// All books with price equal to mentioned list of prices
String priceList = JsonPath.read(jsonString, "$..book[?(@.price in ['12.99', '8.99'])]").toString();
System.out.println("--------------- All books with price equal to mentioned list of prices ---------------");
System.out.println(priceList);

// All books with price NOT equal to mentioned list of prices
String excludePriceList = JsonPath.read(jsonString, "$..book[?(@.price nin ['12.99', '8.99'])]").toString();
System.out.println("---------- All books with price NOT equal to mentioned list of prices ---------");
System.out.println(excludePriceList);

// All books with specified substring (case-sensitive)
String substringExample = JsonPath.read(jsonString, "$..book[?(@.author contains 'Melville')]").toString();
System.out.println("--------------- All books with specified substring (case-sensitive) ---------------");
System.out.println(substringExample);

// All books with an ISBN number
String specificBook = JsonPath.read(jsonString, "$..book[?(@.isbn)]").toString();
System.out.println("--------------- All books with an ISBN number ---------------");
System.out.println(specificBook);