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.service;
019    
020    import org.apache.hadoop.util.ReflectionUtils;
021    import org.apache.oozie.action.ActionExecutor;
022    import org.apache.oozie.service.Service;
023    import org.apache.oozie.service.ServiceException;
024    import org.apache.oozie.service.Services;
025    import org.apache.oozie.util.ParamChecker;
026    import org.apache.oozie.util.XLog;
027    import org.apache.oozie.ErrorCode;
028    
029    import java.util.HashMap;
030    import java.util.Map;
031    
032    public class ActionService implements Service {
033    
034        public static final String CONF_ACTION_EXECUTOR_CLASSES = CONF_PREFIX + "ActionService.executor.classes";
035    
036        public static final String CONF_ACTION_EXECUTOR_EXT_CLASSES = CONF_PREFIX + "ActionService.executor.ext.classes";
037    
038        private Services services;
039        private Map<String, Class<? extends ActionExecutor>> executors;
040    
041        @SuppressWarnings("unchecked")
042        public void init(Services services) throws ServiceException {
043            this.services = services;
044            ActionExecutor.enableInit();
045            ActionExecutor.resetInitInfo();
046            ActionExecutor.disableInit();
047            executors = new HashMap<String, Class<? extends ActionExecutor>>();
048            Class<? extends ActionExecutor>[] classes =
049                    (Class<? extends ActionExecutor>[]) services.getConf().getClasses(CONF_ACTION_EXECUTOR_CLASSES);
050            registerExecutors(classes);
051    
052            classes = (Class<? extends ActionExecutor>[]) services.getConf().getClasses(CONF_ACTION_EXECUTOR_EXT_CLASSES);
053            registerExecutors(classes);
054        }
055    
056        private void registerExecutors(Class<? extends ActionExecutor>[] classes) throws ServiceException {
057            if (classes != null) {
058                for (Class<? extends ActionExecutor> executorClass : classes) {
059                    register(executorClass);
060                }
061            }
062        }
063    
064        public void destroy() {
065            ActionExecutor.enableInit();
066            ActionExecutor.resetInitInfo();
067            ActionExecutor.disableInit();
068            executors = null;
069        }
070    
071        public Class<? extends Service> getInterface() {
072            return ActionService.class;
073        }
074    
075        public void register(Class<? extends ActionExecutor> klass) throws ServiceException {
076            XLog log = XLog.getLog(getClass());
077            ActionExecutor executor = (ActionExecutor) ReflectionUtils.newInstance(klass, services.getConf());
078            if (executors.containsKey(executor.getType())) {
079                throw new ServiceException(ErrorCode.E0150, XLog.format(
080                        "Action executor for action type [{1}] already registered", executor.getType()));
081            }
082            ActionExecutor.enableInit();
083            executor.initActionType();
084            ActionExecutor.disableInit();
085            executors.put(executor.getType(), klass);
086            log.trace("Registered Action executor for action type [{0}] class [{1}]", executor.getType(), klass);
087        }
088    
089        public ActionExecutor getExecutor(String actionType) {
090            ParamChecker.notEmpty(actionType, "actionType");
091            Class<? extends ActionExecutor> executorClass = executors.get(actionType);
092            return (executorClass != null) ? (ActionExecutor) ReflectionUtils.newInstance(executorClass, null) : null;
093        }
094    
095    }