AsyncCallback.java

import com.google.api.core.ApiFuture;
import com.google.api.core.ApiFutureCallback;
import com.google.api.core.ApiFutures;

@Deprecated
public void addTaskCallbacks(Task<String> task) {
  task.addOnSuccessListener(new OnSuccessListener<String>() {
    @Override
    public void onSuccess(String result) {
      System.out.println("Operation completed with result: " + result);
    }
  });
  task.addOnFailureListener(new OnFailureListener() {
    @Override
    public void onFailure(Exception e) {
      System.out.println("Operation failed with error: " + e);
    }
  });
}

public void addFutureCallbacks(ApiFuture<String> future) {
  ApiFutures.addCallback(future, new ApiFutureCallback<String>() {
    @Override
    public void onSuccess(String result) {
      System.out.println("Operation completed with result: " + result);
    }

    @Override
    public void onFailure(Throwable t) {
      System.out.println("Operation failed with error: " + t);
    }
  });
}