001    /*
002     * JBoss DNA (http://www.jboss.org/dna)
003     * See the COPYRIGHT.txt file distributed with this work for information
004     * regarding copyright ownership.  Some portions may be licensed
005     * to Red Hat, Inc. under one or more contributor license agreements.
006     * See the AUTHORS.txt file in the distribution for a full listing of 
007     * individual contributors. 
008     *
009     * JBoss DNA is free software. Unless otherwise indicated, all code in JBoss DNA
010     * is licensed to you under the terms of the GNU Lesser General Public License as
011     * published by the Free Software Foundation; either version 2.1 of
012     * the License, or (at your option) any later version.
013     *
014     * JBoss DNA is distributed in the hope that it will be useful,
015     * but WITHOUT ANY WARRANTY; without even the implied warranty of
016     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
017     * Lesser General Public License for more details.
018     *
019     * You should have received a copy of the GNU Lesser General Public
020     * License along with this software; if not, write to the Free
021     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
022     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
023     */
024    package org.jboss.dna.common.collection;
025    
026    import java.util.LinkedList;
027    import java.util.List;
028    import net.jcip.annotations.NotThreadSafe;
029    
030    /**
031     * A list of problems for some execution context. The problems will be {@link #iterator() returned} in the order in which they
032     * were encountered (although this cannot be guaranteed in contexts involving multiple threads or processes).
033     * 
034     * @author Randall Hauch
035     * @author John Verhaeg
036     */
037    @NotThreadSafe
038    public class SimpleProblems extends AbstractProblems {
039    
040        private List<Problem> problems;
041    
042        /**
043         * {@inheritDoc}
044         * 
045         * @see org.jboss.dna.common.collection.AbstractProblems#addProblem(Problem)
046         */
047        @Override
048        protected void addProblem( Problem problem ) {
049            if (problem == null) return;
050            if (problems == null) problems = new LinkedList<Problem>();
051            problems.add(problem);
052        }
053    
054        /**
055         * {@inheritDoc}
056         * 
057         * @see org.jboss.dna.common.collection.AbstractProblems#getProblems()
058         */
059        @Override
060        protected List<Problem> getProblems() {
061            return this.problems != null ? problems : EMPTY_PROBLEMS;
062        }
063    }