EL函数
自定义EL函数
自定义EL函数
自定义EL函数的注意事项
ElDemo1.java文件
public class ElDemo1 {
public static String sayHello(String name){
return "Hello" + name;
}
}
myfn.dtl文件
<?xml version="1.0" encoding="UTF-8"?>
<taglib version="2.0" 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">
<tlib-version>1.0</tlib-version>
<short-name>myfn</short-name>
<uri>http://www.limaoquan.com/1020/myfn</uri>
<!-- 配置自定义EL函数 -->
<function>
<!-- 配置方法名称 -->
<name>sayHi</name>
<!-- 配置方法所在的类 -->
<function-class>cn.el.ElDemo1</function-class>
<!-- 配置方法的签名 -->
<function-signature>java.lang.String sayHello(java.lang.String)</function-signature>
</function>
</taglib>
自定义标签
自定义标签
现在用右边的过程自定义标签
简单标签
重写5个方法：
- void setJspContext(JspContext pc)
- void setParent(JspTag parent)
- void setJspBody(JspFragment jspBody)
- void doTag()
- JspTag getParent()
执行顺序
自定义标签简介和快速入门
自定义标签的快速入门
图片.png
demo1.java
public class demo1 extends SimpleTagSupport{
private PageContext pc;
@Override
public void doTag() throws JspException, IOException {
pc.getOut().write("hello");
}
/**
* 服务器默认先执行该方法
*/
@Override
public void setJspContext(JspContext pc) {
this.pc = (PageContext)pc;
}
}
配置 mycc.tld
<?xml version="1.0" encoding="UTF-8"?>
<taglib version="2.0" 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">
<tlib-version>1.0</tlib-version>
<short-name>mycc</short-name>
<uri>http://www.limaoquan.com/1020/mycc</uri>
<!-- 配置自定义标签 -->
<tag>
<!-- 配置自定义标签的名称 -->
<name>print</name>
<!-- 配置类的全路径 -->
<tag-class>cn.tag.demo1</tag-class>
<!-- 配置标签主体 -->
<body-content>empty</body-content>
</tag>
</taglib>
引用标签 tag.jsp
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@taglib uri="http://www.limaoquan.com/1020/mycc" prefix="mycc"%>
<!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>
<mycc:print/>
</body>
</html>
带有标签主体的自定义标签
带有标签主体的自定义标签
Body-content的配置
tagDemo2.java
public class TagDemo2 extends SimpleTagSupport{
PageContext pc;
@Override
public void doTag() throws JspException, IOException {
JspFragment jf = getJspBody();
jf.invoke(pc.getOut());
}
@Override
public void setJspContext(JspContext pc) {
this.pc = (PageContext)pc;
}
}
<?xml version="1.0" encoding="UTF-8"?>
<taglib version="2.0" 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">
<tlib-version>1.0</tlib-version>
<short-name>mycc</short-name>
<uri>http://www.limaoquan.com/1020/mycc</uri>
<!-- 配置自定义标签 -->
<tag>
<!-- 配置自定义标签的名称 -->
<name>print</name>
<!-- 配置类的全路径 -->
<tag-class>cn.tag.demo1</tag-class>
<!-- 配置标签主体 -->
<body-content>empty</body-content>
</tag>
<tag>
<name>out</name>
<tag-class>cn.tag.TagDemo2</tag-class>
<body-content>scriptless</body-content>
</tag>
</taglib>
<mycc:out>
妹妹
</mycc:out>
网友评论