/*
* Copyright (c) 2008-2014 MongoDB, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.mongodb.async;
/**
* A SingleResultCallback implementation that saves the result of the callback.
*
* @param <T> the result type
* @since 3.0
*/
class CallbackResultHolder<T> implements SingleResultCallback<T> {
private T result = null;
private Throwable error = null;
private boolean isDone = false;
/**
* Set the result of the callback
*
* @param result the result of the callback
* @param error the throwable error of the callback
*/
public void onResult(final T result, final Throwable error) {
if (isDone) {
throw new IllegalStateException("The CallbackResult cannot be initialized multiple times.");
}
this.result = result;
this.error = error;
this.isDone = true;
}
/**
* Returns the result of the callback or null.
*
* @return the result of the callback if completed or null
*/
public T getResult() {
return result;
}
/**
* Gets the error result of the callback or null.
*
* @return the error result of the callback or null
*/
public Throwable getError() {
return error;
}
/**
* Returns true if the callback returned an error.
*
* @return true if the callback returned an error
*/
public boolean hasError() {
return error != null;
}
/**
* Returns true if the callback has been called.
*
* @return true if the callback has been called
*/
public boolean isDone() {
return isDone;
}
@Override
public String toString() {
return "CallbackResultHolder{"
+ "result=" + result
+ ", error=" + error
+ ", isDone=" + isDone
+ '}';
}
}