/**
* The contents of this file are subject to the license and copyright
* detailed in the LICENSE and NOTICE files at the root of the source
* tree and available online at
*
* http://www.dspace.org/license/
*/
package org.dspace.app.itemupdate;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* Container for UpdateActions
* Order of actions is very import for correct processing. This implementation
* supports an iterator that returns the actions in the order in which they are
* put in. Adding the same action a second time has no effect on this order.
*
*
*/
public class ActionManager implements Iterable<UpdateAction> {
private Map<Class<? extends UpdateAction>, UpdateAction> registry
= new LinkedHashMap<Class<? extends UpdateAction>, UpdateAction>();
public UpdateAction getUpdateAction(Class<? extends UpdateAction> actionClass)
throws InstantiationException, IllegalAccessException
{
UpdateAction action = registry.get(actionClass);
if (action == null)
{
action = actionClass.newInstance();
registry.put(actionClass, action);
}
return action;
}
/**
*
* @return whether any actions have been registered with this manager
*/
public boolean hasActions()
{
return !registry.isEmpty();
}
/**
* This implementation guarantees the iterator order is the same as the order
* in which updateActions have been added
*
* @return iterator for UpdateActions
*/
public Iterator<UpdateAction> iterator()
{
return new Iterator<UpdateAction>()
{
private Iterator<Class<? extends UpdateAction>> itr = registry.keySet().iterator();
public boolean hasNext()
{
return itr.hasNext();
}
public UpdateAction next()
{
return registry.get(itr.next());
}
//not supported
public void remove()
{
throw new UnsupportedOperationException();
}
};
}
}