在Java7中使用current year从组合框中获取选定月份的开始日期和结束日期

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Calendar;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;

public class MonthDateRange {
    public static void main(String[] args) {
        JFrame frame = new JFrame("Month Date Range");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setSize(300, 200);

        // 创建月份组合框
        String[] months = {"January", "February", "March", "April", "May", "June",
                           "July", "August", "September", "October", "November", "December"};
        JComboBox<String> monthComboBox = new JComboBox<>(months);

        // 创建标签显示结果
        JLabel resultLabel = new JLabel("Selected Month: None");

        // 添加事件监听器
        monthComboBox.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                String selectedMonth = (String) monthComboBox.getSelectedItem();
                if (selectedMonth != null) {
                    resultLabel.setText("Selected Month: " + selectedMonth);
                    Calendar calendar = Calendar.getInstance();
                    calendar.set(Calendar.MONTH, monthComboBox.getSelectedIndex());
                    calendar.set(Calendar.DAY_OF_MONTH, 1); // 设置为月份的第一天

                    // 获取月份的开始日期
                    String startDate = String.format("%04d-%02d-%02d",
                            calendar.get(Calendar.YEAR),
                            calendar.get(Calendar.MONTH) + 1,
                            calendar.get(Calendar.DAY_OF_MONTH));

                    // 获取月份的最后一天
                    calendar.add(Calendar.MONTH, 1);
                    calendar.set(Calendar.DAY_OF_MONTH, 0);
                    String endDate = String.format("%04d-%02d-%02d",
                            calendar.get(Calendar.YEAR),
                            calendar.get(Calendar.MONTH),
                            calendar.get(Calendar.DAY_OF_MONTH));

                    System.out.println("Start Date: " + startDate);
                    System.out.println("End Date: " + endDate);
                }
            }
        });

        frame.getContentPane().add(monthComboBox);
        frame.getContentPane().add(resultLabel);
        frame.setVisible(true);
    }
}