时间戳、String、Date转换

时间戳(String or long) =》Date

long s=1557230621043L;
Date date=new Date(s);
System.out.println(date);

Date转时间戳

getTime()

string.date相互转换

//string转date
    public static void stringToDate(){
        try{
            String str="2016-10-24 21:59:06";
            SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
            System.out.println(sdf.parse(str));
            System.out.println(sdf.parse(str).getTime());
        }catch(Exception e){
            e.printStackTrace();
        }
    }

    //date转string1
    public static void dateToString1(){
        try {
            SimpleDateFormat format=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS");
            System.out.println(format.format(new Date().getTime()));
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }

    //date转string2
    public static void dateToString2(){
        try{
            SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS");
            Calendar cal=Calendar.getInstance();
            System.out.println(format.format(cal.getTime()));
        }catch(Exception e){
            e.printStackTrace();
        }
    }

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系统微秒

System.currentTimeMillis();

纳秒

System.nanoTime();