用Java输出上一个月日历

以下是Java代码示例，用于输出上一个月的日历：

import java.time.LocalDate;
import java.time.Month;

public class LastMonthCalendar {
    public static void main(String[] args) {
        LocalDate currentDate = LocalDate.now();
        int currentYear = currentDate.getYear();
        Month currentMonth = currentDate.getMonth();
        int lastMonthLength = currentMonth.minLength();
        LocalDate lastMonthDate = LocalDate.of(currentYear, currentMonth.minus(1), 1);
        int lastMonthStartDay = lastMonthDate.getDayOfWeek().getValue();

        System.out.println(currentMonth + " " + currentYear);
        System.out.println("Mon Tue Wed Thu Fri Sat Sun");

        for (int i = 1; i < lastMonthStartDay; i++) {
            System.out.print("    ");
        }

        for (int i = 1; i <= lastMonthLength; i++) {
            if (i < 10) {
                System.out.print(" ");
            }
            System.out.print(i + " ");
            if ((lastMonthStartDay + i - 1) % 7 == 0) {
                System.out.println();
            }
        }
    }
}

该程序使用Java 8的时间API，获取当前日期并计算上个月的第一天和天数。然后，使用上个月的第一天的星期几来确定日历表格中第一行的间距，以及在循环中打印日历的每个日期。