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w3xue。