Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Add blogpost - How To Get Current Timestamp In Java?#26

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to ourterms of service andprivacy statement. We’ll occasionally send you account related emails.

Already on GitHub?Sign in to your account

Merged
Merged
Changes fromall commits
Commits
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
View file
Open in desktop
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,283 @@
---
layout: post
title: "How To Get Current Timestamp In Java?"
author: gaurav
categories: [Java, Java Time]
description: "In this article, we will see how to get the current timestamp in Java."
---
In this article, we will see how to get the current timestamp in Java.

To get the current timestamp in Java, we can use [`java.time.Instant`](https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html) from Java 8 and [`java.sql.Timestamp`](https://docs.oracle.com/javase/7/docs/api/java/sql/Timestamp.html) till Java 7.

We check both [`java.time.Instant`](https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html) and [`java.sql.Timestamp`](https://docs.oracle.com/javase/7/docs/api/java/sql/Timestamp.html) one by one.

## 1. Using `java.time.Instant` ( for Java 8)
As per the [javadoc](https://docs.oracle.com/javase/8/docs/api/java/time/Instant.html),
> This class models a single instantaneous point on the time-line. This might be used to record event time-stamps in the application.

I have given an example below that shows how to get the current timestamp using `java.time.Instant`

```java
import java.sql.Timestamp;
import java.time.Instant;
import java.util.Date;

/**
* A Java Program to get current timestamp using using the java.time.Instant
*
* @author Gaurav Kukade at coderolls.com
*
*/
public class InstantExample {

public static void main(String[] args) {

Instant instant = Instant.now();
System.out.println("1. instant: "+ instant); // 2021-05-13T15:05:18.734Z


//convert date object to instant
Date date = new Date();
Instant instantFromDate = date.toInstant();

System.out.println("2. instantFromDate: " +instantFromDate); // 2021-05-13T15:05:18.873Z


//get instnat from the java.sql.Timestamp
Timestamp timestamp = new Timestamp(System.currentTimeMillis());
Instant instantFromTimestamp = timestamp.toInstant();

System.out.println("3. instantFromTimestamp: "+ instantFromTimestamp); // 2021-05-13T15:05:18.874Z

//get the epoch timestamp in milliseconds
//epoch timestamp is number of milliseconds since January 1, 1970, 00:00:00 GMT
Instant instant2 = Instant.now();
long timeStampMillis = instant2.toEpochMilli();

System.out.println("4. timeStampMillis: "+ timeStampMillis); // 1620918318874

//get the epoch timestamp in seconds
Instant instant3 = Instant.now();
long timeStampSeconds = instant3.getEpochSecond();

System.out.println("5. timeStampSeconds: "+ timeStampSeconds); // 1620918318

}

}
```
Output:
```
1. instant: 2021-05-13T15:24:19.907Z
2. instantFromDate: 2021-05-13T15:24:19.988Z
3. instantFromTimestamp: 2021-05-13T15:24:19.988Z
4. timeStampMillis: 1620919459988
5. timeStampSeconds: 1620919459
```
### Explanation:

1. In the first case, we have used the `.now()` method of the `Instant` class to get the current timestamp.
2. In the second case, we have created a new `date` object, and then we have used the `.toInstant()` on the `date` object to get the current timestamp.
3. In the third case, we have created a new `timestamp` object using the system time in milliseconds. We can get the system time in millisecond using the `System.currentTimeMillis()`. To get the current timestamp (as instant) we have used the `.toInstant()` method on the `timestamp` object.
4. In the fourth case, we are trying to get the epoch timestamp in milliseconds. We can get it using the `.toEpochMilli()` method on the `instant` object.
5. In the fifth case, we are trying to get the epoch timestamp in seconds. We can get it using the `.getEpochSecond()` method on the `instant` object.

## 2. Using `java.sql.Timestamp` ( for Java 7 and below)

```java
import java.sql.Timestamp;
import java.util.Date;

/**
* A Java program to get the current timestamp using java.sql.Timestamp
*
* @author Gaurav Kukade at coderolls.com
*
*/
public class TimestampExample {

public static void main(String[] args) {

//using system time in milliseconds
Timestamp timestampFromSystemTime = new Timestamp(System.currentTimeMillis());
System.out.println("1. timestampFromSystemTime: "+timestampFromSystemTime); // 2021-05-13 20:55:44.179

//using java.util.Date
Date date = new Date();
Timestamp timestampFromDateObject = new Timestamp(date.getTime());
System.out.println("2. timestampFromDateObject: " +timestampFromDateObject); // 2021-05-13 20:55:44.187

}

}
```
Output:

```
1. timestampFromSystemTime: 2021-05-13 20:55:44.179
2. timestampFromDateObject: 2021-05-13 20:55:44.187
```

### Explanation:

1. In the first case, we are got the `timestamp` using the system time in milliseconds. We can get the system time in millisecond using the `System.currentTimeMillis()`.
2. In the second case, we have created a new `date` object, and then we have used the `.getTime()` on the `date` object to get the current time in milliseconds. We have passed the time milliseconds to timestamp constructor to get the current timestamp.

Sometimes we may need to convert the `java.time.Instant` to `java.sql.Timestamp` or vice versa. So let's see both conversions below.

## How to convert `Instant` to `Timestamp` In Java?

I have given an example below that converts the `java.time.Instant` to `java.sql.Timestamp` class.

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

/**
* A Java Program to convert java.time.Instant to java.sql.Timestamp
*
* @author Gaurav Kukade at coderolls.com
*
*/
public class InstantToTimestamp {

public static void main(String[] args) {

// get Timestamp from Instant
Instant instant = Instant.now();
Timestamp timestamp = Timestamp.from(instant);
System.out.println("Instant To Timestamp: " +timestamp); // 2021-05-13 21:07:44.381


}

}
```

Output:
```
Instant To Timestamp: 2021-05-13 21:07:44.381
```
### Explanation:

In the above example, we have used `.from()` of the `Timestamp` class to get the current timestamp from the `instant` object.

```java
Timestamp timestamp = Timestamp.from(instant);
```


## How to convert `Timestamp` to `Instant` In Java?

I have given an example below that converts the `java.sql.Timestamp` to `java.time.Instant` class.

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

/**
* A Java Program to convert java.sql.Timestamp to java.time.Instant
*
* @author Gaurav Kukade at coderolls.com
*
*/
public class TimestampToInstant {

public static void main(String[] args) {

//get instnat from the java.sql.Timestamp
Timestamp timestamp = new Timestamp(System.currentTimeMillis());
Instant instant = timestamp.toInstant();
System.out.println("Timestamp To Instant: " +instant); // 2021-05-13T15:39:08.046Z

}

}
```

Output:
```
Timestamp To Instant: 2021-05-13T15:39:08.046Z
```
### Explanation:

In the above example, we have used the `.toInstant()` method on the `timestamp` object to get the current timestamp (as Instant ).

## Conclusion

We can get the current timestamp in java using the `Instant` and `Timestamp`.

From Java 8, it is recommended to use the timestamp of the Instant class. We can get the current timestamp from `Instant`as is given below,

```java
Instant instant = Instant.now();

//convert date object to instant
Date date = new Date();
Instant instantFromDate = date.toInstant();

//get instnat from the java.sql.Timestamp
Timestamp timestamp = new Timestamp(System.currentTimeMillis());
Instant instantFromTimestamp = timestamp.toInstant();


//get the epoch timestamp in milliseconds
//epoch timestamp is number of milliseconds since January 1, 1970, 00:00:00 GMT
Instant instant2 = Instant.now();
long timeStampMillis = instant2.toEpochMilli();


//get the epoch timestamp in seconds
Instant instant3 = Instant.now();
long timeStampSeconds = instant3.getEpochSecond();
```

In Java 7 or below, we can use the `Timestamp` class to get the current timestamp.

```java
//using system time in milliseconds
Timestamp timestampFromSystemTime = new Timestamp(System.currentTimeMillis());

//using java.util.Date
Date date = new Date();
System.out.println(date.getTime());
Timestamp timestampFromDateObject = new Timestamp(date.getTime());

```
Also we can convert the `java.time.Instant` to `java.sql.Timestamp` or vice versa.


**Instant To Timestamp**

```java
Instant instant = Instant.now();
Timestamp timestamp = Timestamp.from(instant);
```

**Timestamp to Instant**

```java
Timestamp timestamp = new Timestamp(System.currentTimeMillis());
Instant instant = timestamp.toInstant();
```

That's it for now.

If you have any queries about the above article, please comment below. Thanks.

We will see how to get the current date-time in java. Also, we will see how we can format them using the SimpleDateFormat.

You can check my YouTube channel at: https://www.youtube.com/channel/UCl31HHUdQbSHOQfc9L-wo3w

### Related Articles

- [How To Convert An Integer To String In Java](https://coderolls.com/convert-int-to-string/)

- [How to convert String to Integer in Java](https://coderolls.com/convert-string-to-int/)

- [How To Convert StringBuilder To String In Java?](https://coderolls.com/convert-stringbuilder-to-string-in-java/)

- [How Do I Compare Strings In Java](https://coderolls.com/compare-strings-in-java/)

- [How To Reverse A String In Java (5 ways)](https://coderolls.com/reverse-a-string-in-java/)

[8]ページ先頭
©2009-2025 Movatter.jp