This project has retired. For details please refer to its
Attic page.
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.workflow.lite;
019
020 import org.apache.oozie.workflow.WorkflowException;
021 import org.apache.oozie.workflow.WorkflowInstance;
022 import org.apache.oozie.ErrorCode;
023
024 import java.util.ArrayList;
025 import java.util.List;
026
027 //TODO javadoc
028 public abstract class NodeHandler {
029
030 public interface Context {
031
032 public NodeDef getNodeDef();
033
034 public String getExecutionPath();
035
036 public String getParentExecutionPath(String executionPath);
037
038 public String getSignalValue();
039
040 public void setVar(String name, String value);
041
042 public String getVar(String name);
043
044 public void setTransientVar(String name, Object value);
045
046 public Object getTransientVar(String name);
047
048 public String createExecutionPath(String name);
049
050 //can be called only from exit(), creation of execPaths is automatic
051 //when a handler returns more than one transition.
052 public void deleteExecutionPath();
053
054 //must be used by multiExit
055 public String createFullTransition(String executionPath, String transition);
056
057 public void killJob();
058
059 public void completeJob();
060
061 public LiteWorkflowInstance getProcessInstance();
062 }
063
064 private static final String VISITED = "visited";
065
066 public static String getLoopFlag(String nodeName) {
067 return nodeName + WorkflowInstance.NODE_VAR_SEPARATOR + VISITED;
068 }
069
070 public void loopDetection(Context context) throws WorkflowException {
071 String flag = getLoopFlag(context.getNodeDef().getName());
072 if (context.getVar(flag) != null) {
073 throw new WorkflowException(ErrorCode.E0709, context.getNodeDef().getName());
074 }
075 context.setVar(flag, "true");
076 }
077
078 // TRUE means immediate exit, false means has to be signal
079 public abstract boolean enter(Context context) throws WorkflowException;
080
081 // the return list contains executionPath#transition, important for fork
082 public List<String> multiExit(Context context) throws WorkflowException {
083 List<String> transitions = new ArrayList<String>(1);
084 String transition = exit(context);
085 if (transition != null) {
086 transitions.add(context.createFullTransition(context.getExecutionPath(), transition));
087 }
088 return transitions;
089 }
090
091
092 public abstract String exit(Context context) throws WorkflowException;
093
094 public void kill(Context context) {
095 }
096
097 public void fail(Context context) {
098 }
099 }