ServletPathMapper


1   /*
2    * Copyright 1999-2004 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  package org.apache.commons.chain.web.servlet;
17  
18  
19  import javax.servlet.http.HttpServletRequest  ;
20  import org.apache.commons.chain.Catalog;
21  import org.apache.commons.chain.Command;
22  import org.apache.commons.chain.Context;
23  
24  
25  /**
26   * <p>{@link Command} that uses the "servlet path" component of the request URI
27   * to select a {@link Command} from the appropriate {@link Catalog}, and
28   * execute it.  To use this command, you would typically map an instance
29   * of {@link ChainProcessor} to an extension pattern like "*.execute" and
30   * then arrange that this is the default command to be executed.  In such
31   * an environment, a request for a context relative URI of "/foo.execute"
32   * would cause the "/foo.execute" command to be loaded and executed.</p>
33   *
34   * @author Craig R. McClanahan
35   */
36  
37  public class ServletPathMapper implements Command {
38  
39  
40      // ------------------------------------------------------ Instance Variables
41  
42  
43      private String   catalogKey = ChainProcessor.CATALOG_DEFAULT;
44  
45  
46      // -------------------------------------------------------------- Properties
47  
48  
49      /**
50       * <p>Return the context key under which our {@link Catalog} has been
51       * stored.</p>
52       */
53      public String   getCatalogKey() {
54  
55          return (this.catalogKey);
56  
57      }
58  
59  
60      /**
61       * <p>Set the context key under which our {@link Catalog} has been
62       * stored.</p>
63       *
64       * @param catalogKey The new catalog key
65       */
66      public void setCatalogKey(String   catalogKey) {
67  
68          this.catalogKey = catalogKey;
69  
70      }
71  
72  
73      // --------------------------------------------------------- Command Methods
74  
75  
76      /**
77       * <p>Look up the servlet path information for this request, and use it to
78       * select an appropriate {@link Command} to be executed.
79       *
80       * @param context Context for the current request
81       */
82      public boolean execute(Context context) throws Exception   {
83  
84          // Look up the servlet path for this request
85          ServletWebContext swcontext = (ServletWebContext) context;
86          HttpServletRequest   request = swcontext.getRequest();
87          String   servletPath = (String  )
88              request.getAttribute("javax.servlet.include.servlet_path");
89          if (servletPath == null) {
90              servletPath = request.getServletPath();
91          }
92  
93          // Map to the Command specified by the extra path info
94          Catalog catalog = (Catalog) context.get(getCatalogKey());
95          Command command = catalog.getCommand(servletPath);
96          return (command.execute(context));
97  
98      }
99  
100 
101 }
102
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