java获取年月日期以及Simpoledateformat

谁借莪１个温暖的怀抱￠ 2022-12-05 05:20 39阅读 0赞

## 1.获取年月 ##

Calendar now = Calendar.getInstance();
            int year = now.get(Calendar.YEAR);
            int month = now.get(Calendar.MONDAY)+1;//月份需+1
            System.out.println(year+" "+month);

输出

2020 9

## 2.Date转为格式化字符串 ##

Date now = new Date();
            DateFormat t = new SimpleDateFormat("yyyy-MM-dd H:mm:ss");
            String time = t.format(now);
            System.out.println(time);

输出:

2020-09-09 14:30:43

## 3.字符串转为格式Date对象 ##

Date now = new Date();
            DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd H:mm:ss");
            String dateStr = dateFormat.format(now);
            try { 
                blindPlateEntity.setGmtCreate(dateFormat.parse(dateStr));
            } catch (ParseException e) { 
                e.printStackTrace();
            }

## 4、判断日期字符串是否为周末 ##

import java.text.ParseException;
    import java.text.SimpleDateFormat;
    import java.util.Calendar;
    import java.util.Date;
    
    /**
     * @description: 判断日期字符串是否为周末
     */
    public class IsWeekend { 
        public boolean isWeekend(String dateStr) { 
            boolean isWeekend = false;
            SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            try { 
                Date date = sdf.parse(dateStr);
                Calendar cal = Calendar.getInstance();
                cal.setTime(date);
                isWeekend = cal.get(Calendar.DAY_OF_WEEK) == Calendar.SATURDAY || cal.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY;
            } catch (ParseException e) { 
                e.printStackTrace();
            }
            return isWeekend;
        }
    }

## 5、time时间戳转Date ##

/**
         * time时间戳转Date
         *
         * @param time
         * @return
         */
        public static Date timeToDate(String time) { 
            SimpleDateFormat sdfTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            String str = sdfTime.format(Long.valueOf(time));
            try { 
                Date date = sdfTime.parse(str);
                return date;
            } catch (ParseException e) { 
                e.printStackTrace();
            }
            return null;
        }