JSP带有属性的自定义标签


  1. 新建HelloWelTag类


  2. 如何添加jsp-api.jar包


  3. HelloWelTag类详细代码

package bid.zhazhapan.fims.tag;

import java.io.IOException;

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

public class HelloWelTag extends TagSupport {
    private String name;// 定义对应标签的属性

    // 通过set方法从页面获得name的属性值
    public void setName(String name) {
        this.name = name;
    }

    // 覆盖doEndTag()方法
    public int doEndTag() throws JspException {
        try {
            // 通过pageContext对象获得页面隐式对象out,向客户端输出结果
            pageContext.getOut().write("Welcome " + name);
        } catch (IOException e) {
            e.printStackTrace();
            new JspException("IO Error" + e.getMessage());
        }
        return this.EVAL_PAGE;
    }
}

  • 如何配置xml
  • 
    
    <javaee:taglib version="2.1" xmlns:javaee="http://java.sun.com/xml/ns/javaee" xmlns:xml="http://www.w3.org/XML/1998/namespace" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-jsptaglibrary_2_1.xsd ">
      <javaee:tlib-version>1.0javaee:tlib-version>
      <javaee:short-name>demojavaee:short-name>
      <javaee:uri>/demojavaee:uri>
      <javaee:tag>
        <javaee:name>welcomejavaee:name>
        <javaee:tag-class>bid.zhazhapan.fims.tag.HelloWelTagjavaee:tag-class>
        <javaee:body-content>emptyjavaee:body-content>
        <javaee:attribute>
            <javaee:name>namejavaee:name>
            <javaee:required>truejavaee:required>
            <javaee:rtexprvalue>truejavaee:rtexprvalue>
        javaee:attribute>
      javaee:tag>
    javaee:taglib>

  • 新建test.jsp来测试标签
  • 
    <%@ page language="java" contentType="text/html; charset=ISO-8859-1"
        pageEncoding="ISO-8859-1"%>
    <%@ taglib uri="WEB-INF/tlds/mytag.tld" prefix="mytag" %>
    
    <html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
    <title>Insert title heretitle>
    head>
    <body>
    <mytag:welcome name="<%=\"Tony\" %>" />
    body>
    html>
    



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