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.workflow.lite;
019
020
021import org.apache.oozie.ErrorCode;
022import org.apache.oozie.util.ParamChecker;
023import org.apache.oozie.workflow.WorkflowException;
024
025import java.util.Arrays;
026
027/**
028 * Workflow lite start node definition.
029 */
030public class StartNodeDef extends ControlNodeDef {
031
032    /**
033     * Reserved name fo the start node. <p/> It is an invalid token, it will never match an application node name.
034     */
035    public static final String START = ":start:";
036
037    /**
038     * Default constructor.
039     */
040    public StartNodeDef() {
041    }
042
043    /**
044     * Create a start node definition.
045     *
046     * @param klass control node handler class.
047     * @param transitionTo transition on workflow start.
048     */
049    public StartNodeDef(Class<? extends ControlNodeHandler> klass, String transitionTo) {
050        super(START, "", klass, Arrays.asList(ParamChecker.notEmpty(transitionTo, "transitionTo")));
051    }
052
053    /**
054     * Start node handler. <p/> It does an immediate transition to the transitionTo node.
055     */
056    public static class StartNodeHandler extends NodeHandler {
057
058        public boolean enter(Context context) throws WorkflowException {
059            if (!context.getSignalValue().equals(StartNodeDef.START)) {
060                throw new WorkflowException(ErrorCode.E0715, context.getSignalValue());
061            }
062            return true;
063        }
064
065        public String exit(Context context) {
066            return context.getNodeDef().getTransitions().get(0);
067        }
068
069        public void kill(Context context) {
070        }
071
072        public void fail(Context context) {
073        }
074    }
075
076}