| /******************************************************************************* |
| * Copyright (c) 2001, 2008 Oracle Corporation and others. |
| * 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: |
| * Oracle Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.jst.jsf.common.internal.strategy; |
| |
| import java.util.Iterator; |
| |
| import org.eclipse.jst.jsf.common.JSFCommonPlugin; |
| |
| /** |
| * A composite strategy whos role is to iterate through a number of child |
| * stategies until one returns a valid value for an input. |
| * |
| * @author cbateman |
| * |
| * @param <INPUT> |
| * @param <OUTPUT> |
| * @param <IDTYPE> |
| * @param <STRATEGYTYPE> |
| */ |
| public abstract class StrategyComposite<INPUT, OUTPUT, IDTYPE, STRATEGYTYPE extends IIdentifiableStrategy<INPUT, OUTPUT, IDTYPE>> |
| implements ISimpleStrategy<INPUT, OUTPUT> |
| { |
| public final OUTPUT perform(final INPUT input) |
| { |
| final Iterator<STRATEGYTYPE> sIt = getIterator(); |
| |
| OUTPUT result = getNoResult(); |
| boolean resultFound = false; |
| |
| EXECUTE_LOOP: while (sIt.hasNext()) |
| { |
| final STRATEGYTYPE strategy = sIt.next(); |
| try |
| { |
| result = strategy.perform(input); |
| |
| if (result != strategy.getNoResult()) |
| { |
| resultFound = true; |
| break EXECUTE_LOOP; |
| } |
| } |
| catch (Exception e) |
| { |
| JSFCommonPlugin.log(e); |
| } |
| } |
| |
| if (resultFound) |
| { |
| return result; |
| } |
| return getNoResult(); |
| } |
| |
| /* |
| * (non-Javadoc) |
| * |
| * @see org.eclipse.jst.jsf.common.internal.strategy.ISimpleStrategy#getNoResult() |
| */ |
| public abstract OUTPUT getNoResult(); |
| |
| /** |
| * @return an iterator that will return the next strategy to be executed |
| */ |
| public abstract Iterator<STRATEGYTYPE> getIterator(); |
| } |