Java获取当年以及任意一年的第一天和最后一天 自动获取去年的年份 常用于每年的数据统计

@Slf4j
public class DateTimeUtil {
    
    public static String DEFAULT_FORMAT = "yyyy-MM-dd";
 
    
    public static void main(String[] args) {
        // 测试
        int lastYear = getLastYear();
        getYearFirst(lastYear);

    }

    
    public static Integer getLastYear() {
        SimpleDateFormat formats = new SimpleDateFormat("yyyy");
        Calendar c = Calendar.getInstance();
        c.add(Calendar.YEAR,-1);
        Date date =  c.getTime();
        // Date类型转String类型
        String format = formats.format(date);
        // String类型转int类型
        int parseInt = Integer.parseInt(format);
        log.info("去年为{}年",parseInt);
        return parseInt;
    }

    
    public static String formatDate(Date date){
        SimpleDateFormat f = new SimpleDateFormat(DEFAULT_FORMAT);
        return f.format(date);
    }
     
    
    public static Date getCurrYearFirst(){
        Calendar currCal=Calendar.getInstance();
        int currentYear = currCal.get(Calendar.YEAR);
        return getYearFirst(currentYear);
    }
     
    
    public static Date getCurrYearLast(){
        Calendar currCal=Calendar.getInstance();  
        int currentYear = currCal.get(Calendar.YEAR);
        return getYearLast(currentYear);
    }
     
    
    public static Date getYearFirst(int year){
        Calendar calendar = Calendar.getInstance();
        calendar.clear();
        calendar.set(Calendar.YEAR, year);
        Date currYearFirst = calendar.getTime();
        String nowTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(currYearFirst);
        log.info("去年第一天为{}",nowTime);
        return currYearFirst;
    }
     
    
    public static Date getYearLast(int year){
        Calendar calendar = Calendar.getInstance();
        calendar.clear();
        calendar.set(Calendar.YEAR, year);
        calendar.roll(Calendar.DAY_OF_YEAR, -1);
        return calendar.getTime();
    }
 
}