/*
* JBoss, Home of Professional Open Source
* Copyright 2006, Red Hat Middleware LLC, and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.deployers.spi.deployer.helpers;
import org.jboss.deployers.structure.spi.DeploymentUnit;
/**
* Search a DeploymentUnit structure from child to parent for a matching
* attachment.
*
* @author Scott.Stark@jboss.org
* @author adrian@jboss.org
* @author ales.justin@jboss.org
* @version $Revision:$
*/
public class AttachmentLocator
{
/**
* Get a named attachment
*
* @param unit the deployment unit
* @param name the name of the attachment
* @return the attachment or null if not present
* @throws IllegalArgumentException for a null name
*/
public static Object search(DeploymentUnit unit, String name)
{
Object attachment = null;
while (attachment == null && unit != null)
{
attachment = unit.getAttachment(name);
unit = unit.getParent();
}
return attachment;
}
/**
* Get named attachment of a given type
*
* @param <T> the expected type
* @param unit the deployment unit
* @param name the name of the attachment
* @param expectedType the expected type
* @return the attachment or null if not present
* @throws IllegalArgumentException for a null name or expectedType
*/
public static <T> T search(DeploymentUnit unit, String name, Class<T> expectedType)
{
Object result = search(unit, name);
if (result == null)
return null;
if (expectedType == null)
throw new IllegalArgumentException("Null expected type.");
return expectedType.cast(result);
}
/**
* Get an attachment of the given type
*
* @param <T> the expected type
* @param type the type
* @param unit the deployment unit
* @return the attachment or null if not present
* @throws IllegalArgumentException for a null name or type
*/
public static <T> T search(DeploymentUnit unit, Class<T> type)
{
return search(unit, type.getName(), type);
}
}