Spring MVC使用jstl 标签c:forEach 遍历输出双层嵌套List的数据方式
目录
- Spring MVC jstl 标签c:forEach 遍历输出双层嵌套List数据
- 1、创建Controller
- 2、创建对应的jsp页面
- 注意事项:
- springMVC的forEach不能正常显示
- 1、问题
- 2、解决
Spring MVC jstl 标签c:forEach 遍历输出双层嵌套List数据
具体操作步骤如下:
1、创建Controller
import java.util.ArrayList; import java.util.List; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import org.springframework.stereotype.Controller; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; import com.mahaochen.springmvc.domain.Goods; import com.mahaochen.springmvc.domain.Inventory; @Controller @RequestMapping("/shop") public class ShoppingController { @RequestMapping("/shoppingCart") public String getShoppingCart(HttpServletRequest request, HttpServletResponse response,Model model){ model.addAttribute("list", generateData()); return "shoppingCart"; } private List<Inventory> generateData(){ List<Inventory> inventories = new ArrayList<Inventory>(); for(int i=0 ; i<2 ; i++){ switch (i) { case 0: Inventory inventory1 = new Inventory(); inventory1.setInventoryType("水果"); List<Goods> goodsList1 = new ArrayList<Goods>(); for(int j=0;j<5;j++){ Goods goods = new Goods(); goods.setGoodsName("苹果"+j); goodsList1.add(goods); } inventory1.setGoodList(goodsList1); inventories.add(inventory1); break; default: Inventory inventory2 = new Inventory(); inventory2.setInventoryType("蔬菜"); List<Goods> goodsList2 = new ArrayList<Goods>(); for(int j=0;j<5;j++){ Goods goods = new Goods(); goods.setGoodsName("茄子"+j); goodsList2.add(goods); } inventory2.setGoodList(goodsList2); inventories.add(inventory2); break; } } return inventories; } }
2、创建对应的jsp页面
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <!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>购物车</title> </head> <body> <c:forEach items="${list }" var="item"> ${item.inventoryType}<br /> <c:set value="${item.goodList }" var="subItem"/> <c:forEach items="${subItem }" var="var"> --${var.goodsName }<br /> </c:forEach> </c:forEach> </body> </html>
注意事项:
JSTL1.1的库 在JSP2.0(Servlet 2.4)及以后(推荐用JSTL1.1及以上)用:
<%@taglibprefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
web.xml
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.4" 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-app_2_4.xsd" > </web-app>
在 Servlet2.3及以前,
<%@taglibprefix="c" uri="http://java.sun.com/jstl/core"%>
与2.4比较,以后版本路径少了jsp。
web.xml
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "http://java.sun.com/dtd/web-app_2_3.dtd"> <web-app> </web-app>
不然会出现以下错误:
org.apache.jasper.JasperException:/WEB-INF/jsp/shoppingCart.jsp(line: 10, column: 1) According to TLD or attribute directive in tag file,attribute items does not accept any expressions
springMVC的forEach不能正常显示
1、问题
在进行springMVC的forEach联系时,出现如下错误
org.apache.jasper.JasperException: An exception occurred processing JSP page /WEB-INF/jsp/index.jsp at line 12
<table border="2" bgcolor="aqua" width="500px" > <c:forEach items="${list}" var="student"> <tr > <td height="50px">${student.id}</td> <td height="50px">${student.name}</td> </tr> </c:forEach>
2、解决
forEach的获取是通过getter来进行的,在实体类中添加getter方法即可。
以上为个人经验,希望能给大家一个参考,也希望大家多多支持我们。
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