简单自定义标签

 

第一步：编写一个实现tag接口的实现类

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1. //控制标签体输出   
2. public class SimpleTag1 extends SimpleTagSupport {  
3.   
4.     @Override  
5.     public void doTag() throws JspException, IOException {  
6.         JspFragment jf = this.getJspBody();  
7.   
8.         //循环输出标签体内容   
9. //      for(int i=0; i<10; i++){  
10. ////            jf.invoke(null);   
11. //          jf.invoke(this.getJspContext().getOut());  
12. //      }   
13.           
14.         //忽略本标签之后的jsp代码   
15.         //throw new SkipPageException();  
16.           
17.           
18.         //大小写转换        
19.         StringWriter sw = new StringWriter();  
20.         jf.invoke(sw);  
21.           
22.         String content = sw.getBuffer().toString();  
23.           
24.         content = content.toUpperCase();  
25.           
26.         JspWriter out = this.getJspContext().getOut();  
27.         out.write(content);  
28.           
29.     }  
30.   
31. }  

//控制标签体输出public class SimpleTag1 extends SimpleTagSupport {@Overridepublic void doTag() throws JspException, IOException {JspFragment jf = this.getJspBody();//循环输出标签体内容//for(int i=0; i<10; i++){////jf.invoke(null);//jf.invoke(this.getJspContext().getOut());//}//忽略本标签之后的jsp代码//throw new SkipPageException();//大小写转换StringWriter sw = new StringWriter();jf.invoke(sw);String content = sw.getBuffer().toString();content = content.toUpperCase();JspWriter out = this.getJspContext().getOut();out.write(content);}}

第二步：在tld文件中对标签处理器类进行描述（放在WEB-INF目录下）

可以复制并修改D:\apache-tomcat-6.0.32\webapps\examples\WEB-INF\jsp2中的xml代码
class3g.tld

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1. <?xml version="1.0" encoding="UTF-8" ?>  
2.   
3. <taglib xmlns="http://java.sun.com/xml/ns/j2ee"  
4.     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
5.     xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd"  
6.     version="2.0">  
7.       
8.     <description>there are custom tags of class3g</description>  
9.     <tlib-version>1.0</tlib-version>  
10.     <short-name>class3g</short-name>  
11.     <uri>http://www.class3g.com</uri>  
12.       
13.     <tag>  
14.         <description>demo1</description>  
15.         <name>simpleTag1</name>  
16.         <tag-class>class3g.web.simpleTag.SimpleTag1</tag-class>  
17.         <body-content>scriptless</body-content>  
18.     </tag>  
19.        
20. </taglib>  

<?xml version="1.0" encoding="UTF-8" ?><taglib xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd" version="2.0"> <description>there are custom tags of class3g</description> <tlib-version>1.0</tlib-version> <short-name>class3g</short-name> <uri>http://www.class3g.com</uri> <tag> <description>demo1</description> <name>simpleTag1</name> <tag-class>class3g.web.simpleTag.SimpleTag1</tag-class> <body-content>scriptless</body-content> </tag> </taglib>

第三步:在jsp中导入并使用自定义标签

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1. <pre class="html" name="code"><pre class="html" name="code"><pre class="html" name="code"><%@taglib uri="http://www.class3g.com" prefix="class3g" %>  
2.  <class3g:simpleTag1><h1>我在这!hello!</h1></class3g:simpleTag1>   
3.    xxxxxxxxxxxxxxxxxxxThis is my JSP page. <br>