info.rsdev.xb4j.model.bindings.action.AbstractAction Maven / Gradle / Ivy
/* Copyright 2012 Red Star Development / Dave Schoorl
*
* 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 info.rsdev.xb4j.model.bindings.action;
import info.rsdev.xb4j.exceptions.Xb4jException;
/**
*
* @author Dave Schoorl
*/
public abstract class AbstractAction {
/**
* Cast the context to the expected type
*
* @param
* @param context
* @param type
* @return
* @throws NullPointerException when the context is null
* @throws IllegalArgumentException when the context is not of the expected type
*/
@SuppressWarnings("unchecked")
public static T narrow(Object context, Class type) throws Xb4jException {
if (type == null) {
throw new NullPointerException("Expected type cannot be null");
}
if (context == null) {
throw new NullPointerException(String.format("Context object of type %s cannot be null", type.getName()));
}
if (!type.isAssignableFrom(context.getClass())) {
throw new Xb4jException(String.format("Expected object of type %s, but encountered type %s", type, context.getClass().getName()));
}
return (T) context;
}
}