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.web;
18
19
20 import java.util.Enumeration;
21 import java.util.HashMap;
22 import javax.servlet.ServletRequest;
23 import org.apache.commons.beanutils.BeanUtils;
24 import org.apache.commons.workflow.Context;
25 import org.apache.commons.workflow.Descriptor;
26 import org.apache.commons.workflow.StepException;
27 import org.apache.commons.workflow.base.DescriptorStep;
28
29
30 /**
31 * <p>For each associated <code>Descriptor</code>, populate the properties
32 * of the bean specified by that descriptor from the request parameters of
33 * the current request.</p>
34 *
35 * @version $Revision: 155475 $ $Date: 2005-02-26 13:31:11 +0000 (Sat, 26 Feb 2005) $
36 * @author Craig R. McClanahan
37 */
38
39 public class PopulateStep extends DescriptorStep {
40
41
42 // ----------------------------------------------------------= Constructors
43
44
45 /**
46 * Construct a default instance of this Step.
47 */
48 public PopulateStep() {
49
50 super();
51
52 }
53
54
55 /**
56 * Construct an instance of this Step with the specified identifier.
57 *
58 * @param id Step identifier
59 */
60 public PopulateStep(String id) {
61
62 super();
63 setId(id);
64
65 }
66
67
68 /**
69 * Construct an instance of this Step with the specified identifier
70 * and associated Descriptor.
71 *
72 * @param id Step identifier
73 * @param descriptor Initial descriptor
74 */
75 public PopulateStep(String id, Descriptor descriptor) {
76
77 super();
78 setId(id);
79 addDescriptor(descriptor);
80
81 }
82
83
84 // --------------------------------------------------------- Public Methods
85
86
87 /**
88 * Perform the executable actions related to this Step, in the context of
89 * the specified Context.
90 *
91 * @param context The Context that is tracking our execution state
92 *
93 * @exception StepException if a processing error has occurred
94 */
95 public void execute(Context context) throws StepException {
96
97 // Make sure our executing Context is a WebContext
98 if (!(context instanceof WebContext))
99 throw new StepException("Execution context is not a WebContext",
100 this);
101 WebContext webContext = (WebContext) context;
102 ServletRequest request = webContext.getServletRequest();
103
104 // Prepare a Map of our request parameter names and values
105 // (in Servlet 2.3 we would just call request.getParameterMap())
106 HashMap map = new HashMap();
107 Enumeration names = request.getParameterNames();
108 while (names.hasMoreElements()) {
109 String name = (String) names.nextElement();
110 map.put(name, request.getParameterValues(name));
111 }
112
113 // Process all associated descriptors
114 Descriptor descriptors[] = findDescriptors();
115 for (int i = 0; i < descriptors.length; i++) {
116 Object value = descriptors[i].get(context);
117 if (value == null)
118 throw new StepException
119 ("Cannot retrieve object for " + descriptors[i], this);
120 try {
121 BeanUtils.populate(value, map);
122 } catch (Throwable t) {
123 throw new StepException("Populate exception", t, this);
124 }
125 }
126
127 }
128
129
130 /**
131 * Render a string representation of this Step.
132 */
133 public String toString() {
134
135 StringBuffer sb = new StringBuffer("<web:populate");
136 if (getId() != null) {
137 sb.append(" id=\"");
138 sb.append(getId());
139 sb.append("\"");
140 }
141 sb.append(">");
142 Descriptor descriptors[] = findDescriptors();
143 for (int i = 0; i < descriptors.length; i++)
144 sb.append(descriptors[i].toString());
145 sb.append("</web:populate>");
146 return (sb.toString());
147
148 }
149
150
151 }