以表格格式显示地图，在jsp中以对象为键，数组列表为值 [英] Displaying map in tabular format which has object as key and Arraylist as value in jsp

问题描述

MapKey mapKey = new MapKey(reqId, name, status);     
LinkedHashMap<Object, List<Dashboard>> map = new LinkedHashMap<>();

Mapkey 类:

public class MapKey {
      private Integer id;
      private String name;
      private Integer status;

       public MapKey(Integer id, String name,Integer status) {
        this.id = id;
        this.name = name;
        this.status=status;
      }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }
 //All getters and setters

POJO 类:

public class Dashboard {
    int requestId;
    String loginUser;                  
    int price;                                     
    int status;      
    public int getrequestId() {
        return requestId;
    }
    public void setrequestId(int requestId) {
        requestId= requestId;
    }
     //All getters and setters

JSP 代码:

<TABLE BORDER="1" CELLPADDING="3" CELLSPACING="1" style="text-align: center;"> 
 <TR>     
  <c:forEach var="entry" items="${map}">     
     <TH>${entry.key}</TH>      
  </c:forEach>
 </TR>
 //iterate again
 <c:forEach var="entry" items="${map}">
   //entry.value is ArrayList so we can iterate with c:forEach
  <c:forEach var="headers" items="${entry.value}">
   <TR>         
      <TD>${headers}</TD>         
   </TR>
  </c:forEach>
</c:forEach>
</TABLE>    

输入:

MapKey [reqid=123, name=A,status=1]:[Dashboard [reqid=123, NAME=A, PRICE=5,STATUS=2],Dashboard [reqid=123, NAME=A, PRICE=10,STATUS=3],...,..]
MapKey [reqid=456, name=B,status=2]:[Dashboard [reqid=456, NAME=B, PRICE=20,STATUS=3],Dashboard [reqid=456, NAME=B, PRICE=25,STATUS=2],...,..]

预期输出:

123  A   1   ///Table header 
123 A   5  2
123 A  10  3
//N no of rows 

456 B 2    ///Table header 
456 B  20  3
456 B  25  2
//N no of rows

我有一个 Map，其中 key 是一个 Object，value 是 List.Arraylist，它由每个唯一 reqid 作为对象的行组成.在地图中，键是我的表头，映射中的值是该表头的表数据.键取决于来自 sql 的数据.它可以根据数据而变化.我想将每个键显示为表头和所有它的相关数据作为表的行.我在jsp中编写了代码来为每个键创建表.我是java开发的新手，所以这就是我可以写的.我需要帮助来实现预期的输出.

I have a Map where key is an Object and value is List.Arraylist comprises of rows of each unique reqid as objects. In the map, keys are my table header and the value in the map is the table data for that header.Keys depends on the data from sql.It can be vary as per data.I want to display each key as table header and all its related data as rows of the table.I have written code in jsp to create table for each key.I am newbie in java development,so that is is what I could write.I need help to achieve the expected output.

推荐答案

下面给出了一个最小的、可验证的示例:

Given below is a Minimal, Verifiable Example:

Dashboard.java:

package beans;

public class Dashboard {
    int requestId;
    String loginUser;                  
    int price;                                     
    int status;
    public Dashboard(int requestId, String loginUser, int price, int status) {
        this.requestId = requestId;
        this.loginUser = loginUser;
        this.price = price;
        this.status = status;
    }
    public int getRequestId() {
        return requestId;
    }
    public String getLoginUser() {
        return loginUser;
    }
    public int getPrice() {
        return price;
    }
    public int getStatus() {
        return status;
    } 
}

MapKey.java:

package beans;

public class MapKey {
    private Integer id;
    private String name;
    private Integer status;

    public MapKey(Integer id, String name, Integer status) {
        this.id = id;
        this.name = name;
        this.status = status;
    }

    public Integer getId() {
        return id;
    }

    public String getName() {
        return name;
    }

    public Integer getStatus() {
        return status;
    }
}

AppController.java:

package servlets;

import java.io.IOException;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.RequestDispatcher;
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 beans.Dashboard;
import beans.MapKey;

@WebServlet("/Report")
public class AppController extends HttpServlet {
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doPost(request, response);
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        populateData(request, response);
        RequestDispatcher view = request.getRequestDispatcher("my_page.jsp");
        view.forward(request, response);
    }

    public void populateData(HttpServletRequest request, HttpServletResponse response) {
        Map<MapKey, List<Dashboard>> map = new LinkedHashMap<>();
        map.put(new MapKey(123, "A", 1), List.of(new Dashboard(123, "A", 5, 2), new Dashboard(123, "A", 10, 3)));
        map.put(new MapKey(456, "B", 2), List.of(new Dashboard(456, "B", 20, 3), new Dashboard(456, "B", 25, 2)));
        request.setAttribute("reportMap", map);
    }
}

my_page.jsp:

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
<html>
    <head>
        <title>Applicant Information</title>
    </head>
    <body>
        <table border="1">
            <c:forEach var="map" items="${reportMap}">
                <tr>
                    <td>
                        <table border="1">
                            <tr>
                                <th>${map.key.id}</th><th>${map.key.name}</th><th>${map.key.status}</th>
                            </tr>
                        </table>
                    </td>
                    <td>
                        <table border="1">
                            <c:forEach var="item" items="${map.value}">
                                <tr>
                                    <td>${item.requestId}</td><td>${item.loginUser}</td><td>${item.price}</td><td>${item.status}</td>
                                </tr>
                            </c:forEach>
                        </table>
                    </td>
                </tr>
            </c:forEach>
        </table>
    </body>
</html>

输出:

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