java 获取当前时间的三种方法_js获取时间戳精确到秒

要获取Java中的当前时间戳：

Timestamp timestamp = new Timestamp(System.currentTimeMillis());
//2016-11-16 06:43:19.77

这是两个Java示例，向您展示如何获取Java中的当前时间戳。 （使用Java 8更新）

1. java.sql.Timestamp

获得当前java.sql.Timestamp两种方法

package com.mkyong.date;

import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import java.util.Date;

public class TimeStampExample {

    private static final SimpleDateFormat sdf = new SimpleDateFormat("yyyy.MM.dd.HH.mm.ss");

    public static void main(String[] args) {

        //method 1
        Timestamp timestamp = new Timestamp(System.currentTimeMillis());
        System.out.println(timestamp);

        //method 2 - via Date
        Date date = new Date();
        System.out.println(new Timestamp(date.getTime()));

        //return number of milliseconds since January 1, 1970, 00:00:00 GMT
        System.out.println(timestamp.getTime());

        //format timestamp
        System.out.println(sdf.format(timestamp));
        
    }

}

输出量

2016-11-16 06:43:19.77
2016-11-16 06:43:19.769
1479249799770
2016.11.16.06.43.19

2. java.time.Instant

在Java 8中，可以将java.sql.Timestamp转换为新的java.time.Instant

package com.mkyong.date;

import java.sql.Timestamp;
import java.time.Instant;

public class InstantExample {
    
    public static void main(String[] args) {

        Timestamp timestamp = new Timestamp(System.currentTimeMillis());
        System.out.println(timestamp);

        //return number of milliseconds since January 1, 1970, 00:00:00 GMT
        System.out.println(timestamp.getTime());

        // Convert timestamp to instant
        Instant instant = timestamp.toInstant();
        System.out.println(instant);

        //return number of milliseconds since the epoch of 1970-01-01T00:00:00Z
        System.out.println(instant.toEpochMilli());

        // Convert instant to timestamp
        Timestamp tsFromInstant = Timestamp.from(instant);
        System.out.println(tsFromInstant.getTime());

    }

}

输出量

2016-11-16 06:55:40.11
1479250540110
2016-11-15T22:55:40.110Z
1479250540110
1479250540110

参考文献

1. java.sql.Timestamp JavaDoc
2. java.time.Instant JavaDoc

翻译自: https://mkyong.com/java/how-to-get-current-timestamps-in-java/