Working of interface for beginners Android

AsyncHttp.java

      public class AsyncHttp extends AsyncTask<String, String, String> {

	CallbackToActivity mCallback;//Interface class for callback

	public AsyncHttp(CallbackToActivity mCallback) {

		this.mCallback = mCallback;

	}

	@Override
	protected String doInBackground(String... params) {

		return null;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see android.os.AsyncTask#onPostExecute(java.lang.Object)
	 */
	@Override
	protected void onPostExecute(String result) {
		// execution of result of Long time consuming operation
		
		//After the task ends we can call the interface and pass the ststus to the target class
		mCallback.mStatus(true,,"TaskOver");

	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see android.os.AsyncTask#onPreExecute()
	 */
	@Override
	protected void onPreExecute() {
		// Things to be done before execution of long running operation. For
		// example showing ProgessDialog
		
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see android.os.AsyncTask#onProgressUpdate(Progress[])
	 */
	@Override
	protected void onProgressUpdate(String... text) {

		// Things to be done while execution of long running operation is in
		// progress. For example updating ProgessDialog
	}

}

CallbackToActivity.java

//Interface class handling the status transfer

   public interface CallbackToActivity {


   public void mStatus(boolean status,String message);
   
  /*You can add more than one method as your need with more than one arguments*/

}

ClassName.java

       // implement the interface class to your activity class or fragamet class where you need to get the call back after the async task 
       //in the example am  usng a  activitycalss
       
       public class ClassName extends Activity implements CallbackToActivity
       
       {
           @Override
	     protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		
		AsyncHttp mAsyncHttp=new AsyncHttp(ClassName.this);//You sould implement CallbackToActivity othere wise this methord will show error 
		mAsyncHttp..execute();
      
       }
       
       
       //override methord  comes when we implement the CallbackToActivity.class
       
       @Override
	    public void mStatus(boolean status,String message) {
	    
	    //This methord execute only when user gives a call back from the Asyc Task AsyncHttp.java (in this example)
	        Log.d("Message", "" + message);
	        
	    }
       
       }