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1   /*
2    * $Id: LinkUserTag.java 471754 2006-11-06 14:55:09Z husted $
3    *
4    * Licensed to the Apache Software Foundation (ASF) under one
5    * or more contributor license agreements.  See the NOTICE file
6    * distributed with this work for additional information
7    * regarding copyright ownership.  The ASF licenses this file
8    * to you under the Apache License, Version 2.0 (the
9    * "License"); you may not use this file except in compliance
10   * with the License.  You may obtain a copy of the License at
11   *
12   *  http://www.apache.org/licenses/LICENSE-2.0
13   *
14   * Unless required by applicable law or agreed to in writing,
15   * software distributed under the License is distributed on an
16   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17   * KIND, either express or implied.  See the License for the
18   * specific language governing permissions and limitations
19   * under the License.
20   */
21  
22  
23  package org.apache.struts.webapp.example2;
24  
25  
26  import java.io.IOException;
27  import javax.servlet.http.HttpServletRequest;
28  import javax.servlet.http.HttpServletResponse;
29  import javax.servlet.jsp.JspException;
30  import javax.servlet.jsp.JspWriter;
31  import javax.servlet.jsp.tagext.TagSupport;
32  import org.apache.struts.util.MessageResources;
33  import org.apache.struts.util.ResponseUtils;
34  
35  
36  /**
37   * Generate a URL-encoded hyperlink to the specified URI, with
38   * associated query parameters selecting a specified User.
39   *
40   * @author Craig R. McClanahan
41   * @version $Rev: 471754 $ $Date: 2006-11-06 08:55:09 -0600 (Mon, 06 Nov 2006) $
42   */
43  
44  public class LinkUserTag extends TagSupport {
45  
46  
47      // ------------------------------------------------------ Instance Variables
48  
49  
50      /**
51       * The hyperlink URI.
52       */
53      protected String page = null;
54  
55  
56      /**
57       * The message resources for this package.
58       */
59      protected static MessageResources messages =
60      MessageResources.getMessageResources
61      ("org.apache.struts.webapp.example.ApplicationResources");
62  
63  
64      /**
65       * The attribute name.
66       */
67      private String name = "user";
68  
69  
70      // ------------------------------------------------------------- Properties
71  
72  
73      /**
74       * Return the hyperlink URI.
75       */
76      public String getPage() {
77  
78      return (this.page);
79  
80      }
81  
82  
83      /**
84       * Set the hyperlink URI.
85       *
86       * @param page Set the hyperlink URI
87       */
88      public void setPage(String page) {
89  
90      this.page = page;
91  
92      }
93  
94  
95      /**
96       * Return the attribute name.
97       */
98      public String getName() {
99  
100     return (this.name);
101 
102     }
103 
104 
105     /**
106      * Set the attribute name.
107      *
108      * @param name The new attribute name
109      */
110     public void setName(String name) {
111 
112     this.name = name;
113 
114     }
115 
116 
117     // --------------------------------------------------------- Public Methods
118 
119 
120     /**
121      * Render the beginning of the hyperlink.
122      *
123      * @exception JspException if a JSP exception has occurred
124      */
125     public int doStartTag() throws JspException {
126 
127     // Generate the URL to be encoded
128         HttpServletRequest request =
129             (HttpServletRequest) pageContext.getRequest();
130         StringBuffer url = new StringBuffer(request.getContextPath());
131         url.append(page);
132     User user = null;
133     try {
134         user = (User) pageContext.findAttribute(name);
135         } catch (ClassCastException e) {
136         user = null;
137     }
138     if (user == null)
139         throw new JspException
140             (messages.getMessage("linkUser.noUser", name));
141     if (page.indexOf("?") < 0)
142         url.append("?");
143     else
144         url.append("&");
145     url.append("username=");
146     url.append(ResponseUtils.filter(user.getUsername()));
147 
148     // Generate the hyperlink start element
149     HttpServletResponse response =
150       (HttpServletResponse) pageContext.getResponse();
151     StringBuffer results = new StringBuffer("<a href=\"");
152     results.append(response.encodeURL(url.toString()));
153     results.append("\">");
154 
155     // Print this element to our output writer
156     JspWriter writer = pageContext.getOut();
157     try {
158         writer.print(results.toString());
159     } catch (IOException e) {
160         throw new JspException
161         (messages.getMessage("linkUser.io", e.toString()));
162     }
163 
164     // Evaluate the body of this tag
165     return (EVAL_BODY_INCLUDE);
166 
167     }
168 
169 
170 
171     /**
172      * Render the end of the hyperlink.
173      *
174      * @exception JspException if a JSP exception has occurred
175      */
176     public int doEndTag() throws JspException {
177 
178 
179     // Print the ending element to our output writer
180     JspWriter writer = pageContext.getOut();
181     try {
182         writer.print("</a>");
183     } catch (IOException e) {
184         throw new JspException
185             (messages.getMessage("link.io", e.toString()));
186     }
187 
188     return (EVAL_PAGE);
189 
190     }
191 
192 
193     /**
194      * Release any acquired resources.
195      */
196     public void release() {
197 
198         super.release();
199         this.page = null;
200         this.name = "user";
201 
202     }
203 
204 
205 }