实现 jstl标签foreach 功能

jsp 页面

<%@ page language="java" contentType="text/html; charset=UTF-8"

    pageEncoding="UTF-8"%>

  <%@ include file="/includes/ctx.jsp" %>

  <%@ taglib uri="/RemoveListItems" prefix="z"%>

<!DOCTYPE html >

<html>

<head>

<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">

<title>角色管理</title>

</head>

<body>

	<z:for items="${rolelist}" var="z">

		<p>${z.rolename}</p>

	</z:for>

</body>

</html>

WEB-INF 目录下创建tld 文件

<?xml version="1.0" encoding="UTF-8"?>

<taglib version="2.5" xmlns="http://java.sun.com/xml/ns/javaee"

    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"

    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee">

    <tlibversion>1.0</tlibversion>

    <jspversion>1.1</jspversion>

    <shortname>eRedLab JSPTag Library</shortname>

    <uri>/RemoveListItems</uri>

    <info>自定义标签</info>

    <tag>

        <name>for</name>

        <tagclass>com.oa.tag.Repeater</tagclass>

        <bodycontent>scriptless</bodycontent>

        <info></info>

        <attribute>

            <name>items</name>

            <required>true</required>

            <rtexprvalue>true</rtexprvalue>

        </attribute>

        <attribute>

            <name>var</name>

            <required>true</required>

            <rtexprvalue>true</rtexprvalue>

        </attribute>

        <attribute>

            <name>index</name>

            <required>false</required>

            <rtexprvalue>true</rtexprvalue>

        </attribute>

    </tag>

</taglib>

java 类代码

import java.util.List;

import javax.servlet.jsp.JspException;

import javax.servlet.jsp.tagext.TagSupport;

public class Repeater extends TagSupport {

	/**

	 *

	 */

	private static final long serialVersionUID = 4086401651029717288L;

	private List<?> items;

	private String var;

	private String index;

	private int i;

	@Override

	public int doStartTag() throws JspException {

		if (items == null || items.size() == 0){

			return SKIP_BODY;

		}

		if(index==null)index = "";

		i = 0;

		if(i<items.size()){

			pageContext.setAttribute(var, items.get(i));

			pageContext.setAttribute(index, i);

		}

		return EVAL_BODY_INCLUDE;

	}

	@Override

	public int doAfterBody() throws JspException {

		i++;

		if(i < items.size()){

			pageContext.setAttribute(var, items.get(i));

			pageContext.setAttribute(index, i);

			return EVAL_BODY_AGAIN;

		}

		return SKIP_BODY;

	}

	@Override

	public int doEndTag() throws JspException {

		return EVAL_PAGE;

	}

	public void setItems(List<?> items) {

		this.items = items;

	}

	public void setVar(String var) {

		this.var = var;

	}

	public void setIndex(String index){

		this.index = index;

	}

}

巴特西

实现 jstl标签foreach 功能

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