001 /*
002 * Copyright 1999-2001,2004 The Apache Software Foundation.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 * http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017 package org.apache.commons.workflow.core;
018
019
020 import java.util.EmptyStackException;
021 import org.apache.commons.workflow.BlockState;
022 import org.apache.commons.workflow.Context;
023 import org.apache.commons.workflow.Iterator;
024 import org.apache.commons.workflow.Step;
025 import org.apache.commons.workflow.StepException;
026 import org.apache.commons.workflow.base.BaseStep;
027
028
029 /**
030 * <p>Locate the closest surrounding Iterator, set the nesting control
031 * to <code>true</code>, and transfer control to the Iterator.</p>
032 *
033 * @version $Revision: 155475 $ $Date: 2005-02-26 13:31:11 +0000 (Sat, 26 Feb 2005) $
034 * @author Craig R. McClanahan
035 */
036
037 public class ContinueStep extends BaseStep {
038
039
040 // ----------------------------------------------------------= Constructors
041
042
043 /**
044 * Construct a default instance of this Step.
045 */
046 public ContinueStep() {
047
048 super();
049
050 }
051
052
053 /**
054 * Construct an instance of this Step with the specified identifier.
055 *
056 * @param id Step identifier
057 */
058 public ContinueStep(String id) {
059
060 super();
061 setId(id);
062
063 }
064
065
066 // --------------------------------------------------------- Public Methods
067
068
069 /**
070 * Perform the executable actions related to this Step, in the context of
071 * the specified Context.
072 *
073 * @param context The Context that is tracking our execution state
074 *
075 * @exception StepException if a processing error has occurred
076 */
077 public void execute(Context context) throws StepException {
078
079 // Locate the closest surrounding Iterator's BlockState
080 BlockState state = null;
081 while (true) {
082 try {
083 state = context.peekBlockState();
084 if (state.getBlock() instanceof Iterator)
085 break;
086 context.popBlockState();
087 continue;
088 } catch (EmptyStackException e) {
089 throw new StepException("Must be nested in an Iterator Block",
090 this);
091 }
092 }
093
094 // Set the nesting repeat indicator, and transfer control
095 state.setNest(true);
096 context.setNextStep(state.getBlock());
097
098 }
099
100
101 /**
102 * Render a string representation of this Step.
103 */
104 public String toString() {
105
106 StringBuffer sb = new StringBuffer("<core:continue");
107 if (getId() != null) {
108 sb.append(" id=\"");
109 sb.append(getId());
110 sb.append("\"");
111 }
112 sb.append("/>");
113 return (sb.toString());
114
115 }
116
117
118 }