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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  
18  package org.apache.struts.webapp.example2;
19  
20  
21  import java.io.IOException;
22  import javax.servlet.http.HttpServletRequest;
23  import javax.servlet.http.HttpServletResponse;
24  import javax.servlet.jsp.JspException;
25  import javax.servlet.jsp.JspWriter;
26  import javax.servlet.jsp.tagext.TagSupport;
27  import org.apache.struts.util.MessageResources;
28  import org.apache.struts.util.ResponseUtils;
29  
30  
31  /***
32   * Generate a URL-encoded hyperlink to the specified URI, with
33   * associated query parameters selecting a specified User.
34   *
35   * @author Craig R. McClanahan
36   * @version $Rev: 421494 $ $Date: 2006-07-12 20:55:17 -0700 (Wed, 12 Jul 2006) $
37   */
38  
39  public class LinkUserTag extends TagSupport {
40  
41  
42      // ------------------------------------------------------ Instance Variables
43  
44  
45      /***
46       * The hyperlink URI.
47       */
48      protected String page = null;
49  
50  
51      /***
52       * The message resources for this package.
53       */
54      protected static MessageResources messages =
55  	MessageResources.getMessageResources
56  	("org.apache.struts.webapp.example.ApplicationResources");
57  
58  
59      /***
60       * The attribute name.
61       */
62      private String name = "user";
63  
64  
65      // ------------------------------------------------------------- Properties
66  
67  
68      /***
69       * Return the hyperlink URI.
70       */
71      public String getPage() {
72  
73  	return (this.page);
74  
75      }
76  
77  
78      /***
79       * Set the hyperlink URI.
80       *
81       * @param page Set the hyperlink URI
82       */
83      public void setPage(String page) {
84  
85  	this.page = page;
86  
87      }
88  
89  
90      /***
91       * Return the attribute name.
92       */
93      public String getName() {
94  
95  	return (this.name);
96  
97      }
98  
99  
100     /***
101      * Set the attribute name.
102      *
103      * @param name The new attribute name
104      */
105     public void setName(String name) {
106 
107 	this.name = name;
108 
109     }
110 
111 
112     // --------------------------------------------------------- Public Methods
113 
114 
115     /***
116      * Render the beginning of the hyperlink.
117      *
118      * @exception JspException if a JSP exception has occurred
119      */
120     public int doStartTag() throws JspException {
121 
122 	// Generate the URL to be encoded
123         HttpServletRequest request =
124             (HttpServletRequest) pageContext.getRequest();
125         StringBuffer url = new StringBuffer(request.getContextPath());
126         url.append(page);
127 	User user = null;
128 	try {
129 	    user = (User) pageContext.findAttribute(name);
130         } catch (ClassCastException e) {
131 	    user = null;
132 	}
133 	if (user == null)
134 	    throw new JspException
135 	        (messages.getMessage("linkUser.noUser", name));
136 	if (page.indexOf("?") < 0)
137 	    url.append("?");
138 	else
139 	    url.append("&");
140 	url.append("username=");
141 	url.append(ResponseUtils.filter(user.getUsername()));
142 
143 	// Generate the hyperlink start element
144 	HttpServletResponse response =
145 	  (HttpServletResponse) pageContext.getResponse();
146 	StringBuffer results = new StringBuffer("<a href=\"");
147 	results.append(response.encodeURL(url.toString()));
148 	results.append("\">");
149 
150 	// Print this element to our output writer
151 	JspWriter writer = pageContext.getOut();
152 	try {
153 	    writer.print(results.toString());
154 	} catch (IOException e) {
155 	    throw new JspException
156 		(messages.getMessage("linkUser.io", e.toString()));
157 	}
158 
159 	// Evaluate the body of this tag
160 	return (EVAL_BODY_INCLUDE);
161 
162     }
163 
164 
165 
166     /***
167      * Render the end of the hyperlink.
168      *
169      * @exception JspException if a JSP exception has occurred
170      */
171     public int doEndTag() throws JspException {
172 
173 
174 	// Print the ending element to our output writer
175 	JspWriter writer = pageContext.getOut();
176 	try {
177 	    writer.print("</a>");
178 	} catch (IOException e) {
179 	    throw new JspException
180 	        (messages.getMessage("link.io", e.toString()));
181 	}
182 
183 	return (EVAL_PAGE);
184 
185     }
186 
187 
188     /***
189      * Release any acquired resources.
190      */
191     public void release() {
192 
193         super.release();
194         this.page = null;
195         this.name = "user";
196 
197     }
198 
199 
200 }