001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one
003     * or more contributor license agreements.  See the NOTICE file
004     * distributed with this work for additional information
005     * regarding copyright ownership.  The ASF licenses this file
006     * to you under the Apache License, Version 2.0 (the
007     * "License"); you may not use this file except in compliance
008     * with the License.  You may obtain a copy of the License at
009     * 
010     *      http://www.apache.org/licenses/LICENSE-2.0
011     * 
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    package org.apache.oozie.command;
019    
020    /**
021     * Transition command for materialize the job. The derived class has to override these following functions:
022     * <p/>
023     * loadState() : load the job's and/or actions' state
024     * updateJob() : update job status and attributes
025     * StartChildren() : submit or queue commands to start children
026     * notifyParent() : update the status to upstream if any
027     */
028    public abstract class MaterializeTransitionXCommand extends TransitionXCommand<Void> {
029    
030        /**
031         * The constructor for abstract class {@link MaterializeTransitionXCommand}
032         *
033         * @param name the command name
034         * @param type the command type
035         * @param priority the command priority
036         */
037        public MaterializeTransitionXCommand(String name, String type, int priority) {
038            super(name, type, priority);
039        }
040    
041        /**
042         * The constructor for abstract class {@link MaterializeTransitionXCommand}
043         *
044         * @param name the command name
045         * @param type the command type
046         * @param priority the command priority
047         * @param dryrun true if dryrun is enable
048         */
049        public MaterializeTransitionXCommand(String name, String type, int priority, boolean dryrun) {
050            super(name, type, priority, dryrun);
051        }
052    
053        /* (non-Javadoc)
054         * @see org.apache.oozie.command.TransitionXCommand#transitToNext()
055         */
056        @Override
057        public void transitToNext() throws CommandException {
058        }
059    
060        /**
061         * Materialize the actions for current job
062         * @throws CommandException thrown if failed to materialize
063         */
064        protected abstract void materialize() throws CommandException;
065    
066        /* (non-Javadoc)
067         * @see org.apache.oozie.command.TransitionXCommand#execute()
068         */
069        @Override
070        protected Void execute() throws CommandException {
071            try {
072                materialize();
073                updateJob();
074                performWrites();
075            } finally {
076                notifyParent();
077            }
078            return null;
079        }
080    
081    }