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 */
018package org.apache.oozie.action.decision;
019
020import org.apache.oozie.client.WorkflowAction;
021import org.apache.oozie.action.ActionExecutor;
022import org.apache.oozie.action.ActionExecutorException;
023import org.apache.oozie.util.XLog;
024import org.apache.oozie.util.XmlUtils;
025import org.jdom.Element;
026import org.jdom.JDOMException;
027import org.jdom.Namespace;
028
029import java.util.List;
030
031public class DecisionActionExecutor extends ActionExecutor {
032    public static final String ACTION_TYPE = "switch";
033
034    private static final String TRUE = "true";
035
036    public static final String XML_ERROR = "XML_ERROR";
037
038    public DecisionActionExecutor() {
039        super(ACTION_TYPE);
040    }
041
042    @SuppressWarnings("unchecked")
043    public void start(Context context, WorkflowAction action) throws ActionExecutorException {
044        XLog log = XLog.getLog(getClass());
045        log.trace("start() begins");
046        try {
047            String confStr = action.getConf();
048            context.setStartData("-", "-", "-");
049            Element conf = XmlUtils.parseXml(confStr);
050            Namespace ns = conf.getNamespace();
051
052            String externalState = null;
053
054            for (Element eval : (List<Element>) conf.getChildren("case", ns)) {
055                if (TRUE.equals(eval.getTextTrim())) {
056                    externalState = eval.getAttributeValue("to");
057                    break;
058                }
059            }
060            if (externalState == null) {
061                Element def = conf.getChild("default", ns);
062                if (def != null) {
063                    externalState = def.getAttributeValue("to");
064                }
065            }
066
067            if (externalState == null) {
068                throw new IllegalStateException("Transition cannot be NULL");
069            }
070            // for decision we are piggybacking on external status to transfer the transition,
071            // the {@link ActionEndCommand} does the special handling of setting it as signal value.
072            context.setExecutionData(externalState, null);
073        }
074        catch (JDOMException ex) {
075            throw new ActionExecutorException(ActionExecutorException.ErrorType.FAILED, XML_ERROR, ex.getMessage(), ex);
076        }
077        finally {
078            log.trace("start() ends");
079        }
080    }
081
082    public void end(Context context, WorkflowAction action) throws ActionExecutorException {
083        context.setEndData(WorkflowAction.Status.OK, action.getExternalStatus());
084    }
085
086    public void check(Context context, WorkflowAction action) throws ActionExecutorException {
087        throw new UnsupportedOperationException();
088    }
089
090    public void kill(Context context, WorkflowAction action) throws ActionExecutorException {
091        throw new UnsupportedOperationException();
092    }
093
094    public boolean isCompleted(String externalStatus) {
095        return true;
096    }
097
098}