2-12 编程题-遍历set 以及 map集合

来源：2-12 自由编程

JakePrim

2020-01-15 15:40:54

<%@ 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>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
Set:
<c:forEach items="${requestScope.set }" var="s" varStatus="idx">
	<h2>${idx.index+1 }---${s }</h2>
</c:forEach>
<br>
Map:
<c:forEach items="${requestScope.map }" var="m" varStatus="idx">
	<h2>${idx.index+1 }---key:${m.key }---value:${m.value }</h2>
</c:forEach>
</body>
</html>

servlet

package com.jakeprim.jstl;

import java.io.IOException;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.sun.javafx.collections.MappingChange.Map;

/**
 * Servlet implementation class ForeachServlet
 */
@WebServlet("/foreach")
public class ForeachServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public ForeachServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		Set<String> set = new HashSet<String>();
		set.add("January");
		set.add("February");
		set.add("March");
		set.add("April");
		set.add("May");
		request.setAttribute("set", set);
		
		HashMap<String, String> map = new HashMap<>();
		map.put("May", "1-1");
		map.put("April", "1-2");
		map.put("March", "1-3");
		request.setAttribute("map", map);
		
		request.getRequestDispatcher("/test3.jsp").forward(request, response);
		
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		// TODO Auto-generated method stub
		doGet(request, response);
	}

}

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