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Java > Open Source Codes > org > netbeans > test > taglibrary > handlers > SumBodyTagHandler


1 /*
2  * SumBodyTagHandler.java
3  *
4  * Created on 07 January 2005, 15:00
5  */
6
7 package org.netbeans.test.taglibrary.handlers;
8
9 import java.io.IOException JavaDoc;
10 import javax.servlet.jsp.JspException JavaDoc;
11 import javax.servlet.jsp.JspWriter JavaDoc;
12 import javax.servlet.jsp.tagext.BodyContent JavaDoc;
13 import javax.servlet.jsp.tagext.BodyTagSupport JavaDoc;
14
15 /**
16  * Generated tag handler class.
17  * @author Administrator
18  * @version
19  */
20
21 public class SumBodyTagHandler extends BodyTagSupport JavaDoc {
22
23     /**
24      * Initialization of x property.
25      */
26     private int x = 0;
27
28     /**
29      * Initialization of y property.
30      */
31     private int y = 0;
32     
33     /** Creates new instance of tag handler */
34     public SumBodyTagHandler() {
35         super();
36     }
37     
38     ////////////////////////////////////////////////////////////////
39 /// ///
40 /// User methods. ///
41 /// ///
42 /// Modify these methods to customize your tag handler. ///
43 /// ///
44 ////////////////////////////////////////////////////////////////
45
46     /**
47      * Method called from doStartTag().
48      * Fill in this method to perform other operations from doStartTag().
49      *
50      */
51     private void otherDoStartTagOperations() {
52         //
53 // TODO: code that performs other operations in doStartTag
54 // should be placed here.
55 // It will be called after initializing variables,
56 // finding the parent, setting IDREFs, etc, and
57 // before calling theBodyShouldBeEvaluated().
58 //
59 // For example, to print something out to the JSP, use the following:
60 //
61 // try {
62 // JspWriter out = pageContext.getOut();
63 // out.println("something");
64 // } catch (IOException ex) {
65 // // do something
66 // }
67 //
68 //
69 }
70     
71     /**
72      * Method called from doEndTag()
73      * Fill in this method to perform other operations from doEndTag().
74      *
75      */
76     private void otherDoEndTagOperations() {
77         //
78 // TODO: code that performs other operations in doEndTag
79 // should be placed here.
80 // It will be called after initializing variables,
81 // finding the parent, setting IDREFs, etc, and
82 // before calling shouldEvaluateRestOfPageAfterEndTag().
83 //
84 }
85     
86     /**
87      * Fill in this method to process the body content of the tag.
88      * You only need to do this if the tag's BodyContent property
89      * is set to "JSP" or "tagdependent."
90      * If the tag's bodyContent is set to "empty," then this method
91      * will not be called.
92      */
93     private void writeTagBodyContent(JspWriter JavaDoc out, BodyContent JavaDoc bodyContent) throws IOException JavaDoc {
94         //
95 // TODO: insert code to write html before writing the body content.
96 // e.g.:
97 //
98 out.println("<p>");
99         out.println("Sum of " + x + " and " + y + " is " + (x+y));
100         out.println("<br/>");
101         
102         //
103 // write the body content (after processing by the JSP engine) on the output Writer
104 //
105 bodyContent.writeOut(out);
106         
107         out.println("<br/>");
108         out.println("END of sum");
109         out.println("</p>");
110         
111         
112         // clear the body content for the next time through.
113 bodyContent.clearBody();
114     }
115     
116     ////////////////////////////////////////////////////////////////
117 /// ///
118 /// Tag Handler interface methods. ///
119 /// ///
120 /// Do not modify these methods; instead, modify the ///
121 /// methods that they call. ///
122 /// ///
123 ////////////////////////////////////////////////////////////////
124
125     /**
126      * This method is called when the JSP engine encounters the start tag,
127      * after the attributes are processed.
128      * Scripting variables (if any) have their values set here.
129      * @return EVAL_BODY_BUFFERED if the JSP engine should evaluate the tag body, otherwise return SKIP_BODY.
130      * This method is automatically generated. Do not modify this method.
131      * Instead, modify the methods that this method calls.
132      */
133     
134     public int doStartTag() throws JspException JavaDoc, JspException JavaDoc {
135         otherDoStartTagOperations();
136         
137         if (theBodyShouldBeEvaluated()) {
138             return EVAL_BODY_BUFFERED;
139         } else {
140             return SKIP_BODY;
141         }
142     }
143     
144     /**
145      * This method is called after the JSP engine finished processing the tag.
146      * @return EVAL_PAGE if the JSP engine should continue evaluating the JSP page, otherwise return SKIP_PAGE.
147      * This method is automatically generated. Do not modify this method.
148      * Instead, modify the methods that this method calls.
149      */
150     public int doEndTag() throws JspException JavaDoc, JspException JavaDoc {
151         otherDoEndTagOperations();
152         
153         if (shouldEvaluateRestOfPageAfterEndTag()) {
154             return EVAL_PAGE;
155         } else {
156             return SKIP_PAGE;
157         }
158     }
159     
160     /**
161      * This method is called after the JSP engine processes the body content of the tag.
162      * @return EVAL_BODY_AGAIN if the JSP engine should evaluate the tag body again, otherwise return SKIP_BODY.
163      * This method is automatically generated. Do not modify this method.
164      * Instead, modify the methods that this method calls.
165      */
166     public int doAfterBody() throws JspException JavaDoc {
167         try {
168             //
169 // This code is generated for tags whose bodyContent is "JSP"
170 //
171 BodyContent JavaDoc bodyContent = getBodyContent();
172             JspWriter JavaDoc out = bodyContent.getEnclosingWriter();
173             
174             writeTagBodyContent(out, bodyContent);
175         } catch (Exception JavaDoc ex) {
176             handleBodyContentException(ex);
177         }
178         
179         if (theBodyShouldBeEvaluatedAgain()) {
180             return EVAL_BODY_AGAIN;
181         } else {
182             return SKIP_BODY;
183         }
184     }
185     
186     /**
187      * Handles exception from processing the body content.
188      */
189     private void handleBodyContentException(Exception JavaDoc ex) throws JspException JavaDoc {
190         // Since the doAfterBody method is guarded, place exception handing code here.
191 throw new JspException JavaDoc("error in NewTag: " + ex);
192     }
193     
194     /**
195      * Fill in this method to determine if the rest of the JSP page
196      * should be generated after this tag is finished.
197      * Called from doEndTag().
198      */
199     private boolean shouldEvaluateRestOfPageAfterEndTag() {
200         //
201 // TODO: code that determines whether the rest of the page
202 // should be evaluated after the tag is processed
203 // should be placed here.
204 // Called from the doEndTag() method.
205 //
206 return true;
207     }
208     
209     /**
210      * Fill in this method to determine if the tag body should be evaluated
211      * again after evaluating the body.
212      * Use this method to create an iterating tag.
213      * Called from doAfterBody().
214      */
215     private boolean theBodyShouldBeEvaluatedAgain() {
216         //
217 // TODO: code that determines whether the tag body should be
218 // evaluated again after processing the tag
219 // should be placed here.
220 // You can use this method to create iterating tags.
221 // Called from the doAfterBody() method.
222 //
223 return false;
224     }
225
226     /**
227      * Fill in this method to determine if the tag body should be evaluated.
228      * Called from doStartTag().
229      */
230     private boolean theBodyShouldBeEvaluated() {
231
232         //
233 // TODO: code that determines whether the body should be
234 // evaluated should be placed here.
235 // Called from the doStartTag() method.
236 //
237 return true;
238     }
239
240     /**
241      * Setter for the x attribute.
242      */
243     public void setX(int value) {
244         this.x = value;
245     }
246
247     /**
248      * Setter for the y attribute.
249      */
250     public void setY(int value) {
251         this.y = value;
252     }
253     
254 }
255
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