EL函數(shù)
自定義EL函數(shù)
自定義EL函數(shù)
自定義EL函數(shù)的注意事項(xiàng)
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>
<!-- 配置自定義EL函數(shù) -->
<function>
<!-- 配置方法名稱 -->
<name>sayHi</name>
<!-- 配置方法所在的類 -->
<function-class>cn.el.ElDemo1</function-class>
<!-- 配置方法的簽名 -->
<function-signature>java.lang.String sayHello(java.lang.String)</function-signature>
</function>
</taglib>
自定義標(biāo)簽
自定義標(biāo)簽
現(xiàn)在用右邊的過(guò)程自定義標(biāo)簽
簡(jiǎn)單標(biāo)簽
重寫(xiě)5個(gè)方法：
- void setJspContext(JspContext pc)
- void setParent(JspTag parent)
- void setJspBody(JspFragment jspBody)
- void doTag()
- JspTag getParent()
執(zhí)行順序
自定義標(biāo)簽簡(jiǎn)介和快速入門(mén)
自定義標(biāo)簽的快速入門(mén)
圖片.png
demo1.java
public class demo1 extends SimpleTagSupport{
private PageContext pc;
@Override
public void doTag() throws JspException, IOException {
pc.getOut().write("hello");
}
/**
* 服務(wù)器默認(rèn)先執(zhí)行該方法
*/
@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>
<!-- 配置自定義標(biāo)簽 -->
<tag>
<!-- 配置自定義標(biāo)簽的名稱 -->
<name>print</name>
<!-- 配置類的全路徑 -->
<tag-class>cn.tag.demo1</tag-class>
<!-- 配置標(biāo)簽主體 -->
<body-content>empty</body-content>
</tag>
</taglib>
引用標(biāo)簽 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>
帶有標(biāo)簽主體的自定義標(biāo)簽
帶有標(biāo)簽主體的自定義標(biāo)簽
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>
<!-- 配置自定義標(biāo)簽 -->
<tag>
<!-- 配置自定義標(biāo)簽的名稱 -->
<name>print</name>
<!-- 配置類的全路徑 -->
<tag-class>cn.tag.demo1</tag-class>
<!-- 配置標(biāo)簽主體 -->
<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>
