获取当月天数和前一个月天数

获取当前月天数

/**
     * 获取当月的天数
     */
    public static int getCurrentMonthDay() {
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.DATE, 1);
        calendar.roll(Calendar.DATE, -1);
        int num = calendar.get(Calendar.DATE);
        return num;
    }

获取前一个月的天数

 /**
     * 获取前一个月的天数
     */
    public static int getBeforeMonthDay() {
        Calendar calendar = Calendar.getInstance();
        calendar.add(Calendar.MONTH,-1);
        calendar.set(Calendar.DATE, 1);
        calendar.roll(Calendar.DATE, -1);
        int num = calendar.get(Calendar.DATE);
        return num;
    }