jsp自定义标签库开发

来源：互联网发布：9 9乘法口诀c语言编辑：程序博客网时间：2024/06/07 05:08

1.实现Tag接口。

//标签实现类

package net;

import java.io.IOException;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import javax.servlet.jsp.tagext.Tag;

public class HelloTag implements Tag {

private PageContext pageContext;
private Tag parent;
@Override
public int doEndTag() throws JspException {
  // TODO Auto-generated method stub
  try {
   pageContext.getOut().write("hello,world!!!");
  } catch (IOException e) {
   // TODO Auto-generated catch block
   e.printStackTrace();
  }
  return this.EVAL_PAGE;
}

@Override
public int doStartTag() throws JspException {
  // TODO Auto-generated method stub

  return this.SKIP_BODY;
}

@Override
public Tag getParent() {
// TODO Auto-generated method stub
return parent;
}

@Override
public void release() {
// TODO Auto-generated method stub

}

@Override
public void setPageContext(PageContext arg0) {
// TODO Auto-generated method stub
this.pageContext=arg0;
}

@Override
public void setParent(Tag arg0) {
// TODO Auto-generated method stub
this.parent=arg0;
}

}

//标签描述.tld

<?xml version="1.0" encoding="gbk" ?>

<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 web-jsptaglibrary_2_0.xsd"
    version="2.0">
    <description>A tag library exercising SimpleTag handlers.</description>
    <tlib-version>1.0</tlib-version>

<short-name>examples</short-name>
<uri>/demotag</uri>
<description>
A simple tab library for the examples
</description>

<tag>
<description>Outputs Hello, World</description>
<name>hello_int</name>
<tag-class>net.HelloTag</tag-class>
<body-content>empty</body-content>
</tag>

</taglib>

//在web.xml中指定标签的引用

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4" 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-app_2_4.xsd">
<display-name>
tag</display-name>
<welcome-file-list>
      <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>

<taglib>
       <taglib-uri>/demotag</taglib-uri>
     <taglib-location></taglib-location>
</taglib>

</web-app>

//在jsp中使用标签

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<%@ taglib uri="/demotag" prefix="d" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Insert title here</title>
</head>
<body>

<d:hello_int/>

</body>
</html>