001    /**
002     * Copyright (c) 2010 Yahoo! Inc. All rights reserved.
003     * Licensed under the Apache License, Version 2.0 (the "License");
004     * you may not use this file except in compliance with the License.
005     * You may obtain a copy of the License at
006     *
007     *   http://www.apache.org/licenses/LICENSE-2.0
008     *
009     *  Unless required by applicable law or agreed to in writing, software
010     *  distributed under the License is distributed on an "AS IS" BASIS,
011     *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012     *  See the License for the specific language governing permissions and
013     *  limitations under the License. See accompanying LICENSE file.
014     */
015    package org.apache.oozie.command;
016    
017    /**
018     * Transition command for materialize the job. The derived class has to override these following functions:
019     * <p/>
020     * loadState() : load the job's and/or actions' state
021     * updateJob() : update job status and attributes
022     * StartChildren() : submit or queue commands to start children
023     * notifyParent() : update the status to upstream if any
024     */
025    public abstract class MaterializeTransitionXCommand extends TransitionXCommand<Void> {
026    
027        /**
028         * The constructor for abstract class {@link MaterializeTransitionXCommand}
029         *
030         * @param name the command name
031         * @param type the command type
032         * @param priority the command priority
033         */
034        public MaterializeTransitionXCommand(String name, String type, int priority) {
035            super(name, type, priority);
036        }
037    
038        /**
039         * The constructor for abstract class {@link MaterializeTransitionXCommand}
040         *
041         * @param name the command name
042         * @param type the command type
043         * @param priority the command priority
044         * @param dryrun true if dryrun is enable
045         */
046        public MaterializeTransitionXCommand(String name, String type, int priority, boolean dryrun) {
047            super(name, type, priority, dryrun);
048        }
049    
050        /* (non-Javadoc)
051         * @see org.apache.oozie.command.TransitionXCommand#transitToNext()
052         */
053        @Override
054        public void transitToNext() throws CommandException {
055        }
056    
057        /**
058         * Materialize the actions for current job
059         * @throws CommandException thrown if failed to materialize
060         */
061        protected abstract void materialize() throws CommandException;
062    
063        /* (non-Javadoc)
064         * @see org.apache.oozie.command.TransitionXCommand#execute()
065         */
066        @Override
067        protected Void execute() throws CommandException {
068            try {
069                materialize();
070                updateJob();
071            } finally {
072                notifyParent();
073            }
074            return null;
075        }
076    
077    }