JSP学习笔记(四十四)：编写我的第一个自定义标签

目录WebRoot/WEB-INF下新建标签文件my.tld：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE taglib PUBLIC "-//Sun Microsystems, Inc.//DTD JSP Tag Library 1.2//EN" "http://java.sun.com/dtd/web-jsptaglibrary_1_2.dtd">
<taglib>
    <tlib-version>2.2.3</tlib-version>
    <jsp-version>1.2</jsp-version>
    <short-name>modou</short-name>
    <uri>/modou</uri>
    <display-name>"Modou Tags"</display-name>
    <tag>
    <name>helloworld</name>
    <tag-class>test.MyTag</tag-class>
    <body-content>empty</body-content>
    </tag>
</taglib>

 

建立对应的类文件MyTag.java，需要继承TagSupport类

package test;

import javax.servlet.jsp.JspException;
import javax.servlet.jsp.tagext.TagSupport;

public class MyTag extends TagSupport {

    @Override
    public int doEndTag() throws JspException {
        try {
            pageContext.getOut().print("Hello World!");
        } catch (Exception e) {
        }
        return EVAL_PAGE;
    }

    @Override
    public int doStartTag() throws JspException {
        return EVAL_BODY_INCLUDE;
    }

}

 

现在在网页中就可以使用这个标签了：

<%@ taglib prefix="mytag" uri="/modou" %>

<mytag:helloworld/>