001    /*
002     * JBoss, Home of Professional Open Source.
003     * Copyright 2008, Red Hat Middleware LLC, and individual contributors
004     * as indicated by the @author tags. See the copyright.txt file in the
005     * distribution for a full listing of individual contributors. 
006     *
007     * This is free software; you can redistribute it and/or modify it
008     * under the terms of the GNU Lesser General Public License as
009     * published by the Free Software Foundation; either version 2.1 of
010     * the License, or (at your option) any later version.
011     *
012     * This software is distributed in the hope that it will be useful,
013     * but WITHOUT ANY WARRANTY; without even the implied warranty of
014     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015     * Lesser General Public License for more details.
016     *
017     * You should have received a copy of the GNU Lesser General Public
018     * License along with this software; if not, write to the Free
019     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
020     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
021     */
022    package org.jboss.dna.common.collection;
023    
024    import java.util.LinkedList;
025    import java.util.List;
026    import net.jcip.annotations.NotThreadSafe;
027    
028    /**
029     * A list of problems for some execution context. The problems will be {@link #iterator() returned} in the order in which they
030     * were encountered (although this cannot be guaranteed in contexts involving multiple threads or processes).
031     * 
032     * @author Randall Hauch
033     * @author John Verhaeg
034     */
035    @NotThreadSafe
036    public class SimpleProblems extends AbstractProblems {
037    
038        private List<Problem> problems;
039    
040        /**
041         * {@inheritDoc}
042         * 
043         * @see org.jboss.dna.common.collection.AbstractProblems#addProblem(Problem)
044         */
045        @Override
046        protected void addProblem( Problem problem ) {
047            if (problem == null) return;
048            if (problems == null) problems = new LinkedList<Problem>();
049            problems.add(problem);
050        }
051    
052        /**
053         * {@inheritDoc}
054         * 
055         * @see org.jboss.dna.common.collection.AbstractProblems#getProblems()
056         */
057        @Override
058        protected List<Problem> getProblems() {
059            return this.problems != null ? problems : EMPTY_PROBLEMS;
060        }
061    }