com.almende.util.callback.SyncCallback Maven / Gradle / Ivy

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/*
 * Copyright: Almende B.V. (2014), Rotterdam, The Netherlands
 * License: The Apache Software License, Version 2.0
 */
package com.almende.util.callback;

/**
 * The Class SyncCallback.
 * 
 * @param 
 *            the generic type
 */
public abstract class SyncCallback implements AsyncCallback {
	private T			response	= null;
	private Exception	exception	= null;
	private boolean		done		= false;
	
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * com.almende.eve.agent.callback.AsyncCallback#onSuccess(java.lang.Object)
	 */
	@Override
	public void onSuccess(final T response) {
		this.response = response;
		done = true;
		synchronized (this) {
			notifyAll();
		}
	}
	
	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * com.almende.eve.agent.callback.AsyncCallback#onFailure(java.lang.Exception
	 * )
	 */
	@Override
	public void onFailure(final Exception exception) {
		this.exception = exception;
		done = true;
		synchronized (this) {
			notifyAll();
		}
	}
	
	/**
	 * Get will wait for the request to finish and then return the
	 * response. If an exception is returned, the exception will be
	 * thrown.
	 * 
	 * @return response
	 * @throws Exception
	 *             the exception
	 */
	public T get() throws Exception {
		while (!done) {
			synchronized (this) {
				wait();
			}
		}
		
		if (exception != null) {
			throw exception;
		}
		return response;
	}
};