1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.chain.web.servlet;
18
19
20 import javax.servlet.http.HttpServletRequest;
21 import org.apache.commons.chain.Catalog;
22 import org.apache.commons.chain.Context;
23 import org.apache.commons.chain.Command;
24 import org.apache.commons.chain.generic.LookupCommand;
25
26
27 /**
28 * <p>{@link Command} that uses a specified request parameter
29 * to select a {@link Command} from the appropriate {@link Catalog}, and
30 * execute it. To use this command, you would typically map an instance
31 * of {@link ChainProcessor} to a wildcard pattern like "*.execute" and
32 * then arrange that this is the default command to be executed. In such
33 * an environment, a request for the context-relative path
34 * "/foo.execute?command=bar" would cause the "/bar" command to be loaded
35 * and executed.</p>
36 *
37 * @author Craig R. McClanahan
38 */
39
40 public class RequestParameterMapper extends LookupCommand implements Command {
41
42
43 // ------------------------------------------------------ Instance Variables
44
45
46 private String catalogKey = ChainProcessor.CATALOG_DEFAULT;
47 private String parameter = "command";
48
49
50 // -------------------------------------------------------------- Properties
51
52
53 /**
54 * <p>Return the context key under which our {@link Catalog} has been
55 * stored.</p>
56 *
57 * @return The context key for the Catalog.
58 */
59 public String getCatalogKey() {
60
61 return (this.catalogKey);
62
63 }
64
65
66 /**
67 * <p>Set the context key under which our {@link Catalog} has been
68 * stored.</p>
69 *
70 * @param catalogKey The new catalog key
71 *
72 * @deprecated Use catalogName to specify the name of the catalog in the
73 * catalog factory
74 */
75 public void setCatalogKey(String catalogKey) {
76
77 this.catalogKey = catalogKey;
78
79 }
80
81
82 /**
83 * <p>Return the name of the request parameter to use for
84 * selecting the {@link Command} to be executed.</p>
85 *
86 * @return The name of the request parameter.
87 *
88 * @deprecated Use catalogName to specify the name of the catalog in the
89 * catalog factory
90 */
91 public String getParameter() {
92
93 return (this.parameter);
94
95 }
96
97
98 /**
99 * <p>Set the name of the request parameter to use for
100 * selecting the {@link Command} to be executed.</p>
101 *
102 * @param parameter The new parameter name
103 */
104 public void setParameter(String parameter) {
105
106 this.parameter = parameter;
107
108 }
109
110
111 // --------------------------------------------------------- Command Methods
112
113
114 /**
115 * <p>Look up the specified request paramater for this request, and use it
116 * to select an appropriate {@link Command} to be executed.
117 *
118 * @param context Context for the current request
119 * @return The name of the {@link Command} instance
120 *
121 * @since Chain 1.2
122 */
123 protected String getCommandName(Context context) {
124
125 // Look up the specified request parameter for this request
126 ServletWebContext swcontext = (ServletWebContext) context;
127 HttpServletRequest request = swcontext.getRequest();
128 String value = request.getParameter(getParameter());
129 return value;
130
131 }
132
133
134 /**
135 * <p>Return the {@link Catalog} to look up the {@link Command} in.</p>
136 *
137 * @param context {@link Context} for this request
138 * @return The catalog.
139 * @exception IllegalArgumentException if no {@link Catalog}
140 * can be found
141 *
142 * @since Chain 1.2
143 */
144 protected Catalog getCatalog(Context context) {
145 Catalog catalog = (Catalog) context.get(getCatalogKey());
146 if (catalog == null) {
147 catalog = super.getCatalog(context);
148 }
149 return catalog;
150 }
151
152
153 }
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