JsonPath: Parse the document before querying

In my previous post, I explained how to extract the information from a json document using 'JsonPath.read()' method. If you want to extract the data once this is OK. In case you need to extract other parts of the data as well this is not the way to go since the document will be parsed every time you call JsonPath.read(...). To avoid the problem you can parse the json first.

Example

Object jsonDocument = Configuration.defaultConfiguration().jsonProvider().parse(json);

String firstOrganization = JsonPath.read(jsonDocument, "$.org[0].name");

String secondOrganization = JsonPath.read(jsonDocument, "$.org[1].name");

String firstName = JsonPath.read(jsonDocument, "$.empName.firstName");

String lastName = JsonPath.read(jsonDocument, "$.empName.lastName");

double salary = JsonPath.read(jsonDocument, "$.salary");

Input

{
 "org": [{
  "name": "Honeywell",
  "yrsOfExperience": 2.2
 }, {
  "name": "IBM",
  "yrsOfExperience": 1.8
 }],

 "empName": {
  "firstName": "Krishna",
  "lastName": "Rama"
 },

 "salary": 80000.0
}

App.java

package com.sample.app;

import com.jayway.jsonpath.Configuration;
import com.jayway.jsonpath.JsonPath;

public class App {

 public static void main(String[] args) {

  String json = "{\n" + 
    " \"org\": [{\n" + 
    "  \"name\": \"Honeywell\",\n" + 
    "  \"yrsOfExperience\": 2.2\n" + 
    " }, {\n" + 
    "  \"name\": \"IBM\",\n" + 
    "  \"yrsOfExperience\": 1.8\n" + 
    " }],\n" + 
    "\n" + 
    " \"empName\": {\n" + 
    "  \"firstName\": \"Krishna\",\n" + 
    "  \"lastName\": \"Rama\"\n" + 
    " },\n" + 
    "\n" + 
    " \"salary\": 80000.0\n" + 
    "}";

  Object jsonDocument = Configuration.defaultConfiguration().jsonProvider().parse(json);
  
  String firstOrganization = JsonPath.read(jsonDocument, "$.org[0].name");
  String secondOrganization = JsonPath.read(jsonDocument, "$.org[1].name");
  String firstName = JsonPath.read(jsonDocument, "$.empName.firstName");
  String lastName = JsonPath.read(jsonDocument, "$.empName.lastName");
  double salary = JsonPath.read(jsonDocument, "$.salary");

  System.out.println("firstOrganization : " + firstOrganization);
  System.out.println("secondOrganization : " + secondOrganization);
  System.out.println("firstName : " + firstName);
  System.out.println("lastName : " + lastName);
  System.out.println("salary : " + salary);


 }

}

Output

firstOrganization : Honeywell

secondOrganization : IBM

firstName : Krishna

lastName : Rama

salary : 80000.0

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