1、开发带属性的标签,标签处理器类中属性要有相应setter方法,符合javaBean规范
2、tld文件中进行相应属性标签配置
属性配置相关说明如下图
3、简单标签带属性的例子
1)、通过设置标签属性,自定义循环标签体次数;基本数据类型,JSP页面传递字符串时可以自动转换成相应类型,复合数据类型就不能自动转换,如Date
package TagDemo; import javax.servlet.jsp.JspException; import javax.servlet.jsp.tagext.JspFragment; import javax.servlet.jsp.tagext.SimpleTagSupport; import java.io.IOException; public class SimpleTagWithAttrDemo extends SimpleTagSupport { private int count; public void setCount(int count) { this.count = count; } @Override public void doTag() throws JspException, IOException { JspFragment fragment = this.getJspBody(); for (int i = 0; i < this.count; i++) { fragment.invoke(null); } } }
带属性的自定义简单标签
<?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"> <description>自定义标签</description> <tlib-version>1.0</tlib-version> <short-name>SDT</short-name> <uri>/sefDefineTag</uri> <tag> <name>tagDemo</name> <tag-class>TagDemo.TagDemo</tag-class> <body-content>JSP</body-content> </tag> <tag> <description>测试循环</description> <name>iteration</name> <tag-class>TagDemo.IterationTagDemo</tag-class> <body-content>JSP</body-content> </tag> <tag> <description>测试修改标签体内容</description> <name>bodytag</name> <tag-class>TagDemo.BodyTagDemo</tag-class> <body-content>JSP</body-content> </tag> <tag> <name>simpleTag</name> <tag-class>TagDemo.SimpleTagDemo</tag-class> <!--简单标签中,body-content中一般设置成empty或scriptless,如果设置成JSP会抛异常; 传统标签中,body-content中一般设置成empty或JSP; 如果body-content设置成tagdependent,那么标签体里的内容是给标签处理类使用的, 例如:标签体里的SQL语句,就可以设置成tagdependent,标签处理器类得到SQL语句处理--> <body-content>scriptless</body-content> </tag> <tag> <name>simpleIterationTag</name> <tag-class>TagDemo.SimpleIterationTagDemo</tag-class> <body-content>scriptless</body-content> </tag> <tag> <name>simpleBodyTag</name> <tag-class>TagDemo.SimpleBodyTagDemo</tag-class> <body-content>scriptless</body-content> </tag> <tag> <name>simpleEndPageTag</name> <tag-class>TagDemo.SimpleEndPageTagDemo</tag-class> <body-content>empty</body-content> </tag> <tag> <name>simpleTagAttr</name> <tag-class>TagDemo.SimpleTagWithAttrDemo</tag-class> <body-content>scriptless</body-content> <attribute> <description>标签处理器类count属性值</description> <name>count</name> <required>true</required> <!--rtexprvalue用来指示属性值是否可以是一个表达式--> <rtexprvalue>true</rtexprvalue> </attribute> </tag> </taglib>
tld文件
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <%@taglib prefix="sdt" uri="/sefDefineTag" %> <html> <head> <title></title> </head> <body> <h1>下面是自定义标签:</h1> <h6>---------------------------------------------</h6> <sdt:tagDemo><%="java代码"%>标签体</sdt:tagDemo> <br/> <br/> <sdt:iteration>循环标签体5次<br/></sdt:iteration> <br/> <br/> <sdt:bodytag>abc</sdt:bodytag> <br/> <br/> <sdt:simpleTag>简单标签体</sdt:simpleTag> <br/> <br/> <sdt:simpleIterationTag>简单标签体循环5次<br/></sdt:simpleIterationTag> <br/> <br/> <sdt:simpleBodyTag>abccde</sdt:simpleBodyTag> <br/> <br/> <%--<sdt:simpleEndPageTag></sdt:simpleEndPageTag>--%> <br/> <br/> <!--tld文件标签属性rtexprvalue为true时,属性表达式写法嵌套java代码如,count="<%=2+3%>"--> <sdt:simpleTagAttr count="5">属性标签体循环<br/></sdt:simpleTagAttr> <h6>---------------------------------------------</h6> <div> <h1>自定义标签下面内容</h1> </div> </body> </html>
JSPDemo
2)、标签属性是复合数据类型Date
package TagDemo; import javax.servlet.jsp.JspException; import javax.servlet.jsp.PageContext; import javax.servlet.jsp.tagext.SimpleTagSupport; import java.io.IOException; import java.text.DateFormat; import java.text.SimpleDateFormat; import java.util.Date; public class SimpleTagWithAttrDemo2 extends SimpleTagSupport { private Date date; public void setDate(Date date) { this.date = date; } @Override public void doTag() throws JspException, IOException { PageContext pageContext = (PageContext) this.getJspContext(); DateFormat format=new SimpleDateFormat("yyyy/MM/dd HH:mm:ss"); pageContext.getOut().write(format.format(date)); } }
Date属性自定义标签处理器类
<?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"> <description>自定义标签</description> <tlib-version>1.0</tlib-version> <short-name>SDT</short-name> <uri>/sefDefineTag</uri> <tag> <name>tagDemo</name> <tag-class>TagDemo.TagDemo</tag-class> <body-content>JSP</body-content> </tag> <tag> <description>测试循环</description> <name>iteration</name> <tag-class>TagDemo.IterationTagDemo</tag-class> <body-content>JSP</body-content> </tag> <tag> <description>测试修改标签体内容</description> <name>bodytag</name> <tag-class>TagDemo.BodyTagDemo</tag-class> <body-content>JSP</body-content> </tag> <tag> <name>simpleTag</name> <tag-class>TagDemo.SimpleTagDemo</tag-class> <!--简单标签中,body-content中一般设置成empty或scriptless,如果设置成JSP会抛异常; 传统标签中,body-content中一般设置成empty或JSP; 如果body-content设置成tagdependent,那么标签体里的内容是给标签处理类使用的, 例如:标签体里的SQL语句,就可以设置成tagdependent,标签处理器类得到SQL语句处理--> <body-content>scriptless</body-content> </tag> <tag> <name>simpleIterationTag</name> <tag-class>TagDemo.SimpleIterationTagDemo</tag-class> <body-content>scriptless</body-content> </tag> <tag> <name>simpleBodyTag</name> <tag-class>TagDemo.SimpleBodyTagDemo</tag-class> <body-content>scriptless</body-content> </tag> <tag> <name>simpleEndPageTag</name> <tag-class>TagDemo.SimpleEndPageTagDemo</tag-class> <body-content>empty</body-content> </tag> <tag> <name>simpleTagAttr</name> <tag-class>TagDemo.SimpleTagWithAttrDemo</tag-class> <body-content>scriptless</body-content> <attribute> <description>标签处理器类count属性值</description> <name>count</name> <required>true</required> <!--rtexprvalue用来指示属性值是否可以是一个表达式--> <rtexprvalue>true</rtexprvalue> </attribute> </tag> <tag> <name>simpleTagAttr2</name> <tag-class>TagDemo.SimpleTagWithAttrDemo2</tag-class> <body-content>scriptless</body-content> <attribute> <name>date</name> <required>true</required> <rtexprvalue>true</rtexprvalue> </attribute> </tag> </taglib>
tld文件
<%@ page import="java.util.Date" %> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <%@taglib prefix="sdt" uri="/sefDefineTag" %> <html> <head> <title></title> </head> <body> <h1>下面是自定义标签:</h1> <h6>---------------------------------------------</h6> <sdt:tagDemo><%="java代码"%>标签体</sdt:tagDemo> <br/> <br/> <sdt:iteration>循环标签体5次<br/></sdt:iteration> <br/> <br/> <sdt:bodytag>abc</sdt:bodytag> <br/> <br/> <sdt:simpleTag>简单标签体</sdt:simpleTag> <br/> <br/> <sdt:simpleIterationTag>简单标签体循环5次<br/></sdt:simpleIterationTag> <br/> <br/> <sdt:simpleBodyTag>abccde</sdt:simpleBodyTag> <br/> <br/> <%--<sdt:simpleEndPageTag></sdt:simpleEndPageTag>--%> <br/> <br/> <!--tld文件标签属性rtexprvalue为true时,属性表达式写法嵌套java代码如,count="<%=2+3%>"--> <sdt:simpleTagAttr count="5">属性标签体循环<br/></sdt:simpleTagAttr> <br/> <br/> <% Date now = new Date(); request.setAttribute("date", now); %> <sdt:simpleTagAttr2 date="${date}"></sdt:simpleTagAttr2> <br/> <%--或者这样写:--%> <sdt:simpleTagAttr2 date="<%=new Date()%>"></sdt:simpleTagAttr2> <h6>---------------------------------------------</h6> <div> <h1>自定义标签下面内容</h1> </div> </body> </html>
JSPDemo
时间: 2024-11-05 04:48:08