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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.example;
24  
25  
26  import java.io.IOException;
27  
28  import javax.servlet.http.HttpServletRequest;
29  import javax.servlet.http.HttpServletResponse;
30  import javax.servlet.jsp.JspException;
31  import javax.servlet.jsp.JspWriter;
32  import javax.servlet.jsp.tagext.TagSupport;
33  
34  import org.apache.struts.util.MessageResources;
35  import org.apache.struts.util.ResponseUtils;
36  
37  
38  /**
39   * Generate a URL-encoded hyperlink to the specified URI, with
40   * associated query parameters selecting a specified User.
41   *
42   * @author Craig R. McClanahan
43   * @version $Rev: 471754 $ $Date: 2006-11-06 08:55:09 -0600 (Mon, 06 Nov 2006) $
44   */
45  
46  public class LinkUserTag extends TagSupport {
47  
48  
49      // ------------------------------------------------------ Instance Variables
50  
51  
52      /**
53       * The hyperlink URI.
54       */
55      protected String page = null;
56  
57  
58      /**
59       * The message resources for this package.
60       */
61      protected static MessageResources messages =
62      MessageResources.getMessageResources
63      ("org.apache.struts.webapp.example.ApplicationResources");
64  
65  
66      /**
67       * The attribute name.
68       */
69      private String name = "user";
70  
71  
72      // ------------------------------------------------------------- Properties
73  
74  
75      /**
76       * Return the hyperlink URI.
77       */
78      public String getPage() {
79  
80      return (this.page);
81  
82      }
83  
84  
85      /**
86       * Set the hyperlink URI.
87       *
88       * @param page Set the hyperlink URI
89       */
90      public void setPage(String page) {
91  
92      this.page = page;
93  
94      }
95  
96  
97      /**
98       * Return the attribute name.
99       */
100     public String getName() {
101 
102     return (this.name);
103 
104     }
105 
106 
107     /**
108      * Set the attribute name.
109      *
110      * @param name The new attribute name
111      */
112     public void setName(String name) {
113 
114     this.name = name;
115 
116     }
117 
118 
119     // --------------------------------------------------------- Public Methods
120 
121 
122     /**
123      * Render the beginning of the hyperlink.
124      *
125      * @exception JspException if a JSP exception has occurred
126      */
127     public int doStartTag() throws JspException {
128 
129     // Generate the URL to be encoded
130         HttpServletRequest request =
131             (HttpServletRequest) pageContext.getRequest();
132         StringBuffer url = new StringBuffer(request.getContextPath());
133         url.append(page);
134     User user = null;
135     try {
136         user = (User) pageContext.findAttribute(name);
137         } catch (ClassCastException e) {
138         user = null;
139     }
140     if (user == null)
141         throw new JspException
142             (messages.getMessage("linkUser.noUser", name));
143     if (page.indexOf("?") < 0)
144         url.append("?");
145     else
146         url.append("&");
147     url.append("username=");
148     url.append(ResponseUtils.filter(user.getUsername()));
149 
150     // Generate the hyperlink start element
151     HttpServletResponse response =
152       (HttpServletResponse) pageContext.getResponse();
153     StringBuffer results = new StringBuffer("<a href=\"");
154     results.append(response.encodeURL(url.toString()));
155     results.append("\">");
156 
157     // Print this element to our output writer
158     JspWriter writer = pageContext.getOut();
159     try {
160         writer.print(results.toString());
161     } catch (IOException e) {
162         throw new JspException
163         (messages.getMessage("linkUser.io", e.toString()));
164     }
165 
166     // Evaluate the body of this tag
167     return (EVAL_BODY_INCLUDE);
168 
169     }
170 
171 
172 
173     /**
174      * Render the end of the hyperlink.
175      *
176      * @exception JspException if a JSP exception has occurred
177      */
178     public int doEndTag() throws JspException {
179 
180 
181     // Print the ending element to our output writer
182     JspWriter writer = pageContext.getOut();
183     try {
184         writer.print("</a>");
185     } catch (IOException e) {
186         throw new JspException
187             (messages.getMessage("link.io", e.toString()));
188     }
189 
190     return (EVAL_PAGE);
191 
192     }
193 
194 
195     /**
196      * Release any acquired resources.
197      */
198     public void release() {
199 
200         super.release();
201         this.page = null;
202         this.name = "user";
203 
204     }
205 
206 
207 }