Source code

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
019package org.apache.oozie.command;
020
021import org.apache.oozie.ErrorCode;
022import org.apache.oozie.client.Job;
023
024/**
025 * Transition command for pause the job. The derived class has to override these following functions:
026 * <p/>
027 * updateJob() : update job status and attributes
028 * pauseChildren() : submit or queue commands to pause children
029 * notifyParent() : update the status to upstream if any
030 *
031 * @param <T>
032 */
033public abstract class PauseTransitionXCommand extends TransitionXCommand<Void> {
034    /**
035     * The constructor for abstract class {@link PauseTransitionXCommand}
036     *
037     * @param name the command name
038     * @param type the command type
039     * @param priority the command priority
040     */
041    public PauseTransitionXCommand(String name, String type, int priority) {
042        super(name, type, priority);
043    }
044
045    /**
046     * pause actions associated with the job
047     *
048     * @throws CommandException thrown if failed to pause actions
049     */
050    public abstract void pauseChildren() throws CommandException;
051
052    /* (non-Javadoc)
053     * @see org.apache.oozie.command.TransitionXCommand#transitToNext()
054     */
055    @Override
056    public final void transitToNext() throws CommandException {
057        if (job == null) {
058            job = this.getJob();
059        }
060
061        if (job.getStatus() == Job.Status.RUNNING) {
062            job.setStatus(Job.Status.PAUSED);
063        }
064        else if (job.getStatus() == Job.Status.RUNNINGWITHERROR) {
065            job.setStatus(Job.Status.PAUSEDWITHERROR);
066        }
067        else if (job.getStatus() == Job.Status.PREP) {
068            job.setStatus(Job.Status.PREPPAUSED);
069        }
070        else {
071            throw new CommandException(ErrorCode.E1315, job.getId());
072        }
073
074        //TODO: to be revisited;
075        //job.setPending();
076    }
077
078    /* (non-Javadoc)
079     * @see org.apache.oozie.command.TransitionXCommand#execute()
080     */
081    @Override
082    protected Void execute() throws CommandException {
083        try {
084            transitToNext();
085            updateJob();
086            pauseChildren();
087        }
088        finally {
089            notifyParent();
090        }
091        return null;
092    }
093}