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.executor.jpa;
016    
017    import java.util.List;
018    
019    import javax.persistence.EntityManager;
020    import javax.persistence.Query;
021    
022    import org.apache.oozie.CoordinatorActionBean;
023    import org.apache.oozie.ErrorCode;
024    import org.apache.oozie.util.ParamChecker;
025    
026    /**
027     * Load coordinator actions in READY state for a coordinator job.
028     */
029    public class CoordJobGetReadyActionsJPAExecutor implements JPAExecutor<List<CoordinatorActionBean>> {
030    
031        private String coordJobId = null;
032        private int numResults;
033        private String executionOrder = null;
034    
035        public CoordJobGetReadyActionsJPAExecutor(String coordJobId, int numResults, String executionOrder) {
036            ParamChecker.notNull(coordJobId, "coordJobId");
037            this.coordJobId = coordJobId;
038            this.numResults = numResults;
039            this.executionOrder = executionOrder;
040        }
041    
042        @Override
043        public String getName() {
044            return "CoordJobGetReadyActionsJPAExecutor";
045        }
046    
047        @Override
048        @SuppressWarnings("unchecked")
049        public List<CoordinatorActionBean> execute(EntityManager em) throws JPAExecutorException {
050            List<CoordinatorActionBean> actionBeans = null;
051            try {
052                Query q;
053                // check if executionOrder is FIFO, LIFO, or LAST_ONLY
054                if (executionOrder.equalsIgnoreCase("FIFO")) {
055                    q = em.createNamedQuery("GET_COORD_ACTIONS_FOR_JOB_FIFO");
056                }
057                else {
058                    q = em.createNamedQuery("GET_COORD_ACTIONS_FOR_JOB_LIFO");
059                }
060                q.setParameter("jobId", coordJobId);
061                
062                // if executionOrder is LAST_ONLY, only retrieve first record in LIFO,
063                // otherwise, use numResults if it is positive.
064                if (executionOrder.equalsIgnoreCase("LAST_ONLY")) {
065                    q.setMaxResults(1);
066                }
067                else {
068                    if (numResults > 0) {
069                        q.setMaxResults(numResults);
070                    }
071                }
072                actionBeans = q.getResultList();
073                return actionBeans;
074            }
075            catch (Exception e) {
076                throw new JPAExecutorException(ErrorCode.E0603, e);
077            }        
078        }
079    
080    }