(Java) JSON: Miscellaneous Operations

Demonstrates a variety of JSON API methods. This example uses the following JSON document:

{
   "alphabet": "abcdefghijklmnopqrstuvwxyz",
   "sampleData" : {
           "pi": 3.14,
	   "apple": "juicy",
	   "hungry": true,
	   "withoutValue": null,
           "answer": 42
          
	}
}

Chilkat Java Downloads Java Libs for Windows, MacOS, Linux, Alpine Linux, Solaris Java Libs for Android

import com.chilkatsoft.*;

public class ChilkatExample {

  static {
    try {
        System.loadLibrary("chilkat");
    } catch (UnsatisfiedLinkError e) {
      System.err.println("Native code library failed to load.\n" + e);
      System.exit(1);
    }
  }

  public static void main(String argv[])
  {
    CkJsonObject json = new CkJsonObject();
    json.put_EmitCompact(false);

    // Assume the file contains the data as shown above..
    boolean success = json.LoadFile("qa_data/json/sample2.json");
    if (success != true) {
        System.out.println(json.lastErrorText());
        return;
        }

    // First navigate to the "sampleData" object:
    CkJsonObject sampleData = json.ObjectOf("sampleData");

    // Demonstrate BoolAt and BoolOf
    System.out.println("hungry: " + sampleData.BoolOf("hungry"));
    System.out.println("hungry: " + sampleData.BoolAt(2));

    // StringOf returns the value as a string regardless of it's actual type:
    System.out.println("pi: " + sampleData.stringOf("pi"));
    System.out.println("answer: " + sampleData.stringOf("answer"));
    System.out.println("withoutValue: " + sampleData.stringOf("withoutValue"));
    System.out.println("hungry: " + sampleData.stringOf("hungry"));

    // Demonstrate IsNullOf / IsNullAt
    System.out.println("withoutValue is null? " + sampleData.IsNullOf("withoutValue"));
    System.out.println("withoutValue is null? " + sampleData.IsNullAt(3));
    System.out.println("apple is null? " + sampleData.IsNullOf("apple"));
    System.out.println("apple is null? " + sampleData.IsNullAt(1));

    // IntOf
    System.out.println("answer: " + sampleData.IntOf("answer"));

    // SetNullAt, SetNullOf
    // Set "pi" to null
    success = sampleData.SetNullAt(0);
    // Set "answer" to null
    success = sampleData.SetNullOf("answer");

    // Show the changes:
    System.out.println(json.emit());

    // Restore pi and apple:
    success = sampleData.SetNumberAt(0,"3.14");
    success = sampleData.SetNumberOf("answer","42");

    // Show the changes:
    System.out.println(json.emit());

    // Add a null value named "afterApple" just after "apple"
    success = sampleData.AddNullAt(2,"afterApple");

    // Add a boolean value just after "pi"
    success = sampleData.AddBoolAt(1,"afterPi",false);

    // Examine the changes..
    System.out.println(json.emit());
  }
}