JavaでJsonPointerインターフェースを使用してキーの値を取得するにはどうすればよいですか？

import javax.json.*;
import java.io.*;
public class JsonPointerTest {
   public static void main(String[] args) throws Exception {
      JsonReader jsonReader = Json.createReader(new FileReader("simple.json"));
      JsonStructure jsonStructure = jsonReader.read();
      JsonPointer jsonPointer1 = Json.createPointer("/firstName");
      JsonString jsonString = (JsonString)jsonPointer1.getValue(jsonStructure);
      System.out.println("First Name: " + jsonString.getString()); // prints first name
      JsonPointer jsonPointer2 = Json.createPointer("/phoneNumbers");
      JsonArray array = (JsonArray)jsonPointer2.getValue(jsonStructure);
      System.out.println("Phone Numbers:");
      for(JsonValue value : array) {
         JsonObject objValue = (JsonObject)value;
         System.out.println(objValue.toString()); // prints phone numbers
      }
      JsonPointer jsonPointer3 = Json.createPointer("/phoneNumbers/1");
      JsonObject jsonObject1 = (JsonObject)jsonPointer3.getValue(jsonStructure);
      System.out.println("Home: " + jsonObject1.toString()); // prints home phone number
      JsonPointer jsonPointer4 = Json.createPointer("");
      JsonObject jsonObject2 = (JsonObject)jsonPointer4.getValue(jsonStructure);
      System.out.println("JSON:\n" + jsonObject2.toString()); // prints JSON structure
      jsonReader.close();
   }
}

First Name: Raja
Phone Numbers:
{"Mobile":"9959984000"}
{"Home":"0403758000"}
Home: {"Home":"0403758000"}
JSON:
{"firstName":"Raja","lastName":"Ramesh","age":30,"streetAddress":"Madhapur","city":"Hyderabad","state":"Telangana","phoneNumbers":[{"Mobile":"9959984000"},{"Home":"0403758000"}]}