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一个具体的类继承TagSupport

定义的类必须在包之下

打印一句:HelloWord!!

通过上下文获取输出流

package  com.xiaomaha.mytag;

import  java.io.IOException;

import  javax.servlet.jsp.JspException;
import  javax.servlet.jsp.JspWriter;
import  javax.servlet.jsp.tagext.TagSupport;

public   class  HelloWord  extends  TagSupport  ... {

    @Override
     public   int  doStartTag()  throws  JspException  ... {
        JspWriter w  =  pageContext.getOut();
         try   ... {
            w.println( " HelloWord!!! " );
        }   catch  (IOException e)  ... {
             //  TODO Auto-generated catch block
            e.printStackTrace();
        }
         return   super .doStartTag();
    }

}

 

定义一个xml文件

 

<? xml version="1.0" encoding="UTF-8" ?>
<! DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN" "web-jsptaglibrary_1_2.dtd"  >
< taglib >
   < tlib-version > tlib-version </ tlib-version >
   < jsp-version > jsp-version </ jsp-version >
   < short-name > short-name </ short-name >
   < tag >
     < name > hello </ name >
     < tag-class > com.xiaomaha.mytag.HelloWord </ tag-class >
   </ tag >
</ taglib >

jsp调用

引用:   <%@taglib uri="/WEB-INF/hello.xml" prefix="h"%>

<% ... @ page language = " java "  import = " java.util.* "  pageEncoding = " UTF-8 " %>
<% ...
String  path  =  request.getContextPath();
String  basePath  =  request.getScheme() + " :// " + request.getServerName() + " : " + request.getServerPort() + path + " / " ;
%>
<% ... @taglib uri = " /WEB-INF/hello.xml "  prefix = " h " %>
<! DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" >
< html >
   < head >
     < base  href ="<%=basePath%>" >
    
     < title > My JSP 'index.jsp' starting page </ title >
     < meta  http-equiv ="pragma"  content ="no-cache" >
     < meta  http-equiv ="cache-control"  content ="no-cache" >
     < meta  http-equiv ="expires"  content ="0" >     
     < meta  http-equiv ="keywords"  content ="keyword1,keyword2,keyword3" >
     < meta  http-equiv ="description"  content ="This is my page" >
     <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
     -->
   </ head >
  
   < body >  
     < h:hello ></ h:hello >
   </ body >
</ html >

 

http:localhost:9999/TestTag