(Android™) Check if Integer Exists at JSON Path

Demonstrates how to get an integer value at a JSON path, and how to check to see if it exists.

Chilkat Android™ Downloads Android™ Java Libraries Android C/C++ Libraries

// 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);

    CkJsonObject json = new CkJsonObject();
    boolean success;

    // First build simple JSON..
    json.UpdateInt("test.abc",100);

    json.put_EmitCompact(false);
    Log.i(TAG, json.emit());

    // This is our JSON:
    // {
    //   "test": {
    //     "abc": 100,
    //   }
    // }

    String path = "test.notHere";

    // The call to IntOf will return 0, because it's not present.
    // But how do we know if it really was present, and the value was truly 0?
    int val = json.IntOf(path);
    Log.i(TAG, "val = " + String.valueOf(val));

    // We cannot use LastMethodSuccess because LastMethodSuccess only applies
    // to methods that:
    // - return a string
    // - return a new Chilkat object, binary bytes, or a date/time.
    // - returns a boolean status where true = success and false = failed.
    // - returns an integer where failure is defined by a return value less than zero.
    // The IntOf method fits none of these requirements, and therefore the LastMethodSuccess 
    // is not a valid indicator..
    boolean wasFound = json.get_LastMethodSuccess();
    Log.i(TAG, "wasFound = " + String.valueOf(wasFound) + " (not a valid indicator)");

    // Instead, if the returned value is 0, we can double-check to see if the member was truly there..
    if (val == 0) {
        wasFound = json.HasMember(path);
        Log.i(TAG, "wasFound = " + String.valueOf(wasFound));
        if (wasFound == true) {
            Log.i(TAG, "The value was present and is 0.");
            }
        else {
            Log.i(TAG, "no member is present at test.notHere");
            }

        }
    else {
        Log.i(TAG, "val = " + String.valueOf(val));
        }

    // Alternatively, you could check to see if the member exists beforehand..
    if (json.HasMember(path) == true) {
        Log.i(TAG, "val = " + String.valueOf(json.IntOf(path)));
        }
    else {
        Log.i(TAG, "no member at " + path);
        }


  }

  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."
  }
}