View Javadoc

1   /*
2    * Copyright 1999-2001,2004 The Apache Software Foundation.
3    * 
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * 
8    *      http://www.apache.org/licenses/LICENSE-2.0
9    * 
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */ 
16  
17  package org.apache.commons.workflow.core;
18  
19  
20  import java.util.EmptyStackException;
21  import org.apache.commons.workflow.Context;
22  import org.apache.commons.workflow.Descriptor;
23  import org.apache.commons.workflow.StepException;
24  import org.apache.commons.workflow.base.DescriptorStep;
25  
26  
27  /**
28   * <p>For each associated <code>Descriptor</code>, pop the top value from
29   * the evaluation stack, and store it as specified by that Descriptor,
30   * in the order that descriptors are listed.</p>
31   *
32   * @version $Revision: 155475 $ $Date: 2005-02-26 13:31:11 +0000 (Sat, 26 Feb 2005) $
33   * @author Craig R. McClanahan
34   */
35  
36  public class PutStep extends DescriptorStep {
37  
38  
39      // ----------------------------------------------------------= Constructors
40  
41  
42      /**
43       * Construct a default instance of this Step.
44       */
45      public PutStep() {
46  
47          super();
48  
49      }
50  
51  
52      /**
53       * Construct an instance of this Step with the specified identifier.
54       *
55       * @param id Step identifier
56       */
57      public PutStep(String id) {
58  
59          super();
60          setId(id);
61  
62      }
63  
64  
65      /**
66       * Construct an instance of this Step with the specified identifier
67       * and associated Descriptor.
68       *
69       * @param id Step identifier
70       * @param descriptor Initial descriptor
71       */
72      public PutStep(String id, Descriptor descriptor) {
73  
74          super();
75          setId(id);
76          addDescriptor(descriptor);
77  
78      }
79  
80  
81      // --------------------------------------------------------- Public Methods
82  
83  
84      /**
85       * Perform the executable actions related to this Step, in the context of
86       * the specified Context.
87       *
88       * @param context The Context that is tracking our execution state
89       *
90       * @exception StepException if a processing error has occurred
91       */
92      public void execute(Context context) throws StepException {
93  
94          // Process all associated descriptors
95          Descriptor descriptors[] = findDescriptors();
96          for (int i = 0; i < descriptors.length; i++) {
97              Object value = null;
98              try {
99                  value = context.pop();
100             } catch (EmptyStackException e) {
101                 throw new StepException("Evaluation stack is empty", e, this);
102             }
103             descriptors[i].put(context, value);
104         }
105 
106     }
107 
108 
109 }