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.workflow.lite;
016    
017    import org.apache.oozie.workflow.WorkflowException;
018    import org.apache.oozie.ErrorCode;
019    
020    
021    //TODO javadoc
022    public abstract class DecisionNodeHandler extends NodeHandler {
023    
024        @Override
025        public final boolean enter(Context context) throws WorkflowException {
026            start(context);
027            return false;
028        }
029    
030        @Override
031        public final String exit(Context context) throws WorkflowException {
032            end(context);
033            String signalValue = context.getSignalValue();
034            if (context.getNodeDef().getTransitions().contains(signalValue)) {
035                return signalValue;
036            }
037            else {
038                throw new WorkflowException(ErrorCode.E0721, context.getNodeDef().getName(), signalValue);
039            }
040        }
041    
042        public abstract void start(Context context) throws WorkflowException;
043    
044        public abstract void end(Context context) throws WorkflowException;
045    
046    }