MessageCatalog.java

/* 
 * Copyright (c) 2009, 2012 IBM Corp.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Dave Locke - initial API and implementation and/or initial documentation
 */
package org.eclipse.paho.client.mqttv3.internal;

/**
 * Catalog of human readable error messages.
 */
public abstract class MessageCatalog {
	private static MessageCatalog INSTANCE = null;

	public static final String getMessage(int id) {
		if (INSTANCE == null) {
			if (ExceptionHelper.isClassAvailable("java.util.ResourceBundle")) {
				try {
					// Hide this class reference behind reflection so that the class does not need to
					// be present when compiled on midp
					INSTANCE = (MessageCatalog)Class.forName("org.eclipse.paho.client.mqttv3.internal.ResourceBundleCatalog").newInstance();
				} catch (Exception e) {
					return "";
				}
			} else if (ExceptionHelper.isClassAvailable("org.eclipse.paho.client.mqttv3.internal.MIDPCatalog")){
				try {
					INSTANCE = (MessageCatalog)Class.forName("org.eclipse.paho.client.mqttv3.internal.MIDPCatalog").newInstance();
				} catch (Exception e) {
					return "";
				}
			}
		}
		return INSTANCE.getLocalizedMessage(id);
	}
	
	protected abstract String getLocalizedMessage(int id);
}