由于开发过程中，有一些工作大同小异，想通用的做一个标签。今天，想研究一下。下面，把学习的过程，记录下来。以备查阅。
1.首先测试一下容器和web环境。不管三七二十一，跟着讲解的内容，一字字的敲出来。
自定义tag ，主要分为2部门。
1.定义JAVA文件
package com.randy.tag;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.TagSupport;
public class HelloTag extends TagSupport {
@Override
public int doEndTag() throws JspException {
// TODO Auto-generated method stub
try {
JspWriter out = pageContext.getOut();
out.println( "标签开始了");
out.println( "<font color=\"red\">hello tag</font>");
} catch (IOException e) {
e.printStackTrace();
}
return EVAL_BODY_INCLUDE;
}
@Override
public int doStartTag() throws JspException {
try {
JspWriter out = pageContext.getOut();
out.println( "<br/>");
} catch (IOException e) {
e.printStackTrace();
}
return SKIP_PAGE;
}
}
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspWriter;
import javax.servlet.jsp.tagext.TagSupport;
public class HelloTag extends TagSupport {
@Override
public int doEndTag() throws JspException {
// TODO Auto-generated method stub
try {
JspWriter out = pageContext.getOut();
out.println( "标签开始了");
out.println( "<font color=\"red\">hello tag</font>");
} catch (IOException e) {
e.printStackTrace();
}
return EVAL_BODY_INCLUDE;
}
@Override
public int doStartTag() throws JspException {
try {
JspWriter out = pageContext.getOut();
out.println( "<br/>");
} catch (IOException e) {
e.printStackTrace();
}
return SKIP_PAGE;
}
}
2.下面 是编写tld文件，并将tld 放到WEB_INF 下
<?
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" >
< tlib-version >1.0 </ tlib-version >
< short-name >myTagLib </ short-name >
< uri >/myTag </ uri >
< tag >
< description >Outputs Hello, World </ description >
< name >helloTag </ name >
< tag-class >com.randy.tag.HelloTag </ tag-class >
< body-content >empty </ body-content >
</ tag >
</ taglib >
< 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" >
< tlib-version >1.0 </ tlib-version >
< short-name >myTagLib </ short-name >
< uri >/myTag </ uri >
< tag >
< description >Outputs Hello, World </ description >
< name >helloTag </ name >
< tag-class >com.randy.tag.HelloTag </ tag-class >
< body-content >empty </ body-content >
</ tag >
</ taglib >
最后，在web.xml 中部署一下
<
taglib
>
< taglib-uri >/myTag </ taglib-uri >
< taglib-location >/WEB-INF/mytag.tld </ taglib-location >
</ taglib >
< taglib-uri >/myTag </ taglib-uri >
< taglib-location >/WEB-INF/mytag.tld </ taglib-location >
</ taglib >
在JSP 中可以使用了
<%@ page language=
"java" contentType=
"text/html; charset=UTF-8"
pageEncoding= "UTF-8"%>
<%@taglib prefix= "myTag" uri= "/myTag" %>
<%@taglib prefix= "html" uri= "/WEB-INF/struts-html.tld" %>
<%@page import= "java.util.*" %>
<!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=UTF-8">
<title>Insert title here</title>
</head>
<body>
<myTag:helloTag/>
<hr/>
</body>
</html>
pageEncoding= "UTF-8"%>
<%@taglib prefix= "myTag" uri= "/myTag" %>
<%@taglib prefix= "html" uri= "/WEB-INF/struts-html.tld" %>
<%@page import= "java.util.*" %>
<!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=UTF-8">
<title>Insert title here</title>
</head>
<body>
<myTag:helloTag/>
<hr/>
</body>
</html>
该标签，没有标签体。没有属性。可以在此基础上，继续学习中。
本文转自 randy_shandong 51CTO博客，原文链接：http://blog.51cto.com/dba10g/282607，如需转载请自行联系原作者
