如何将JTableModel横向展示客房预订数据？

当前问题 #

通过查询获取了包含日期（Tarikh）和房间（Room）的ResultSet，涉及9间客房，时间范围为2022年1月1日至1月31日。使用net.proteanit.sql.DbUtils将ResultSet转换为JTableModel后，表格是纵向结构：

Room    Date            Booked
101 2022-01-01  2022-01-01
102 2022-01-01  2022-01-01
103 2022-01-01  2022-01-01
104 2022-01-01  2022-01-01
105 2022-01-01  null
106 2022-01-01  null
107 2022-01-01  null
108 2022-01-01  null
109 2022-01-01  null
101 2022-01-02  null
102 2022-01-02  2022-01-02
...（以此类推）

需要改成横向结构：以房间号为行、日期为列，已预订单元格标记为X，示例如下：

0101  0201 0301 0401 0501 ...
101      X 
102      X     X
103      X 
104      X
105
106
107
108
109

实现步骤 #

1. 从ResultSet提取并整理数据 #

先遍历ResultSet，把房间号、日期以及对应的预订信息整理到集合和Map中，方便后续构建模型：

import java.sql.ResultSet;
import java.sql.Date;
import java.time.LocalDate;
import java.util.*;

// 初始化存储结构
Set<String> rooms = new TreeSet<>(); // TreeSet保证房间号有序
Set<LocalDate> dates = new TreeSet<>(); // TreeSet保证日期有序
Map<String, Set<LocalDate>> roomBookings = new HashMap<>();

// 遍历ResultSet提取数据
while (resultSet.next()) {
    String roomNum = resultSet.getString("Room");
    LocalDate date = resultSet.getDate("Date").toLocalDate();
    Date bookedDateSql = resultSet.getDate("Booked");
    LocalDate bookedDate = bookedDateSql != null ? bookedDateSql.toLocalDate() : null;

    // 记录房间和日期
    rooms.add(roomNum);
    dates.add(date);

    // 初始化当前房间的预订集合
    roomBookings.computeIfAbsent(roomNum, k -> new HashSet<>());
    // 如果已预订，添加日期到集合
    if (bookedDate != null) {
        roomBookings.get(roomNum).add(bookedDate);
    }
}

// 转成有序列表方便后续使用
List<String> roomList = new ArrayList<>(rooms);
List<LocalDate> dateList = new ArrayList<>(dates);

2. 自定义JTableModel #

继承AbstractTableModel，按照横向矩阵的逻辑实现方法：

import javax.swing.table.AbstractTableModel;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.time.LocalDate;

class RoomBookingTableModel extends AbstractTableModel {
    private final List<String> roomList;
    private final List<LocalDate> dateList;
    private final Map<String, Set<LocalDate>> roomBookings;

    public RoomBookingTableModel(List<String> roomList, List<LocalDate> dateList, Map<String, Set<LocalDate>> roomBookings) {
        this.roomList = roomList;
        this.dateList = dateList;
        this.roomBookings = roomBookings;
    }

    @Override
    public int getRowCount() {
        return roomList.size(); // 行数等于房间数
    }

    @Override
    public int getColumnCount() {
        return 1 + dateList.size(); // 第一列是房间号，后面是日期列
    }

    @Override
    public String getColumnName(int column) {
        if (column == 0) {
            return "房间号";
        }
        // 将日期格式化为MMdd格式（比如0101）
        LocalDate targetDate = dateList.get(column - 1);
        return String.format("%02d%02d", targetDate.getMonthValue(), targetDate.getDayOfMonth());
    }

    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        String currentRoom = roomList.get(rowIndex);
        if (columnIndex == 0) {
            return currentRoom;
        }
        // 获取当前列对应的日期
        LocalDate targetDate = dateList.get(columnIndex - 1);
        // 检查该房间是否在该日期预订，是则返回X，否则返回空字符串
        return roomBookings.get(currentRoom).contains(targetDate) ? "X" : "";
    }
}

3. 应用自定义模型到JTable #

最后把自定义模型设置给JTable即可：

import javax.swing.JTable;

RoomBookingTableModel customModel = new RoomBookingTableModel(roomList, dateList, roomBookings);
JTable bookingTable = new JTable(customModel);

内容的提问来源于stack exchange，提问作者Hussin S Mohamed