Android™

ITIDA Canonicalize JSON and Compute SHA256 Hash

See more Egypt ITIDA Examples

Demonstrates creating the canonical (ITIDA) version of a JSON document, and then computes the SHA256 hash of the canonicalized JSON. Android™

// Important: Don't forget to include the call to System.loadLibrary
// as shown at the bottom of this code sample.
package com.test;

import android.app.Activity;
import com.chilkatsoft.*;

import android.widget.TextView;
import android.os.Bundle;

public class SimpleActivity extends Activity {

  private static final String TAG = "Chilkat";

  // Called when the activity is first created.
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    boolean success = false;

    //  This example assumes the Chilkat API to have been previously unlocked.
    //  See Global Unlock Sample for sample code.

    //  Load the JSON containing the document to be signed.

    //  The JSON file should look like this:
    //  NOTE: The JSON should NOT begin with "{ "documents" : [ ..."

    //        {
    //           "issuer":{
    //              "address":{
    //                 "branchID":"0",
    //                 "country":"EG",
    //                 "regionCity":"Cairo",
    //                 "postalCode":"",
    //                 "buildingNumber":"0",
    //                 "street":"123rd Street",
    //                 "governate":"GOVERNATE"
    //              },
    //              "type":"B",
    //              "id":"209999899",
    //              "name":"Xyz SAE"
    //           },
    //  ...
    //  ...

    CkStringBuilder sb = new CkStringBuilder();
    success = sb.LoadFile("my_invoice.json","utf-8");
    if (success == false) {
        Log.i(TAG, "Failed to load input file.");
        return;
        }

    //  Convert the contents of sb to the ITIDA canonical form.
    //  Always pass utf-8 for the 2nd arg.
    sb.Encode("itida","utf-8");

    //  Examine the canonicalized JSON
    Log.i(TAG, sb.getAsString());

    //  Compute the SHA256 hash and show the SHA256 in hex format
    Log.i(TAG, "SHA256 hash: " + sb.getHash("sha256","hex","utf-8"));

  }

  static {
      System.loadLibrary("chilkat");

      // Note: If the incorrect library name is passed to System.loadLibrary,
      // then you will see the following error message at application startup:
      //"The application <your-application-name> has stopped unexpectedly. Please try again."
  }
}