Java timestamp to instant

Java Convert Timestamp to Instant

In this Java core tutorial we learn how to convert a java.sql.Timestamp object to a java.time.Instant object in Java programming language.

How to convert Timestamp to Instant in Java

In Java, with a given Timestamp object we can use the Timestamp.toInstant() method to convert it to Instant object as the following example Java code.

import java.sql.Timestamp; import java.time.Instant; public class ConvertTimestampToInstantExample1  public static void main(String. args)  Timestamp timestamp = new Timestamp(System.currentTimeMillis()); // Convert Timestamp object to Instant object Instant instant = timestamp.toInstant(); System.out.println("Timestamp: " + timestamp); System.out.println("Instant: " + instant); > >

Timestamp: 2022-05-24 18:38:42.174 Instant: 2022-05-24T11:38:42.174Z

Источник

Convert Between java.time.Instant and java.sql.Timestamp

The Kubernetes ecosystem is huge and quite complex, so it’s easy to forget about costs when trying out all of the exciting tools.

To avoid overspending on your Kubernetes cluster, definitely have a look at the free K8s cost monitoring tool from the automation platform CAST AI. You can view your costs in real time, allocate them, calculate burn rates for projects, spot anomalies or spikes, and get insightful reports you can share with your team.

Connect your cluster and start monitoring your K8s costs right away:

We rely on other people’s code in our own work. Every day.

It might be the language you’re writing in, the framework you’re building on, or some esoteric piece of software that does one thing so well you never found the need to implement it yourself.

The problem is, of course, when things fall apart in production — debugging the implementation of a 3rd party library you have no intimate knowledge of is, to say the least, tricky.

Lightrun is a new kind of debugger.

It’s one geared specifically towards real-life production environments. Using Lightrun, you can drill down into running applications, including 3rd party dependencies, with real-time logs, snapshots, and metrics.

Learn more in this quick, 5-minute Lightrun tutorial:

Slow MySQL query performance is all too common. Of course it is. A good way to go is, naturally, a dedicated profiler that actually understands the ins and outs of MySQL.

The Jet Profiler was built for MySQL only, so it can do things like real-time query performance, focus on most used tables or most frequent queries, quickly identify performance issues and basically help you optimize your queries.

Critically, it has very minimal impact on your server’s performance, with most of the profiling work done separately — so it needs no server changes, agents or separate services.

Basically, you install the desktop application, connect to your MySQL server, hit the record button, and you’ll have results within minutes:

DbSchema is a super-flexible database designer, which can take you from designing the DB with your team all the way to safely deploying the schema.

The way it does all of that is by using a design model, a database-independent image of the schema, which can be shared in a team using GIT and compared or deployed on to any database.

And, of course, it can be heavily visual, allowing you to interact with the database using diagrams, visually compose queries, explore the data, generate random data, import data or build HTML5 database reports.

The Kubernetes ecosystem is huge and quite complex, so it’s easy to forget about costs when trying out all of the exciting tools.

To avoid overspending on your Kubernetes cluster, definitely have a look at the free K8s cost monitoring tool from the automation platform CAST AI. You can view your costs in real time, allocate them, calculate burn rates for projects, spot anomalies or spikes, and get insightful reports you can share with your team.

Connect your cluster and start monitoring your K8s costs right away:

We’re looking for a new Java technical editor to help review new articles for the site.

1. Overview

Both java.time.Instant and java.sql.Timestamp classes represent a point on the timeline in UTC. In other words, they represent the number of nanoseconds since the Java epoch.

In this quick tutorial, we’ll convert one to the other by using built-in Java methods.

2. Converting Instant to Timestamp and Back

We can use Timestamp.from() to convert Instants into Timestamps:

Instant instant = Instant.now(); Timestamp timestamp = Timestamp.from(instant); assertEquals(instant.toEpochMilli(), timestamp.getTime());

And vice-versa, we can use Timestamp.toInstant() to convert Timestamps into Instants:

instant = timestamp.toInstant(); assertEquals(instant.toEpochMilli(), timestamp.getTime());

Either way, both the Instant and Timestamp represents the same point on the timeline.

Next, let’s have a look at the interaction between the two classes and the timezone.

3. toString() Method Differences

Invoking toString() on Instant and Timestamp behaves differently with respect to timezone. Instant.toString() returns the time in UTC timezone. On the other hand, Timezone.toString() returns the time in the local machine timezone.

Let’s see what we get when calling toString() on instant and timestamp respectively:

Instant (in UTC): 2018-10-18T00:00:57.907Z Timestamp (in GMT +05:30): 2018-10-18 05:30:57.907

Here, timestamp.toString() resulted in a time which is 5 hours 30 minutes after the time returned by the instant.toString(). This is because the local machine’s timezone is at GMT +5:30 timezone.

The output of the toString() method is different, but both the timestamp and instant represent the same point on the timeline.

We can also verify this by converting the Timestamp to the UTC time zone:

DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); formatter = formatter.withZone(TimeZone.getTimeZone("UTC").toZoneId()); DateFormat df = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); assertThat(formatter.format(instant)).isEqualTo(df.format(timestamp));

4. Conclusion

In this quick tutorial, we saw how to convert between java.time.Instant and java.sql.Timestamp classes in Java using built-in methods.

We also had a look at how the time zone affects how the output changes.

And, as always, the complete code examples are available over on GitHub.

Slow MySQL query performance is all too common. Of course it is. A good way to go is, naturally, a dedicated profiler that actually understands the ins and outs of MySQL.

The Jet Profiler was built for MySQL only, so it can do things like real-time query performance, focus on most used tables or most frequent queries, quickly identify performance issues and basically help you optimize your queries.

Critically, it has very minimal impact on your server’s performance, with most of the profiling work done separately — so it needs no server changes, agents or separate services.

Basically, you install the desktop application, connect to your MySQL server, hit the record button, and you’ll have results within minutes:

Источник

Class Timestamp

A thin wrapper around java.util.Date that allows the JDBC API to identify this as an SQL TIMESTAMP value. It adds the ability to hold the SQL TIMESTAMP fractional seconds value, by allowing the specification of fractional seconds to a precision of nanoseconds. A Timestamp also provides formatting and parsing operations to support the JDBC escape syntax for timestamp values.

• 19 , which is the number of characters in yyyy-mm-dd hh:mm:ss
• 20 + s , which is the number of characters in the yyyy-mm-dd hh:mm:ss.[fff. ] and s represents the scale of the given Timestamp, its fractional seconds precision.

Note: This type is a composite of a java.util.Date and a separate nanoseconds value. Only integral seconds are stored in the java.util.Date component. The fractional seconds — the nanos — are separate. The Timestamp.equals(Object) method never returns true when passed an object that isn’t an instance of java.sql.Timestamp , because the nanos component of a date is unknown. As a result, the Timestamp.equals(Object) method is not symmetric with respect to the java.util.Date.equals(Object) method. Also, the hashCode method uses the underlying java.util.Date implementation and therefore does not include nanos in its computation.

Due to the differences between the Timestamp class and the java.util.Date class mentioned above, it is recommended that code not view Timestamp values generically as an instance of java.util.Date . The inheritance relationship between Timestamp and java.util.Date really denotes implementation inheritance, and not type inheritance.

Источник

Java timestamp to instant

Note: This type is a composite of a java.util.Date and a separate nanoseconds value. Only integral seconds are stored in the java.util.Date component. The fractional seconds — the nanos — are separate. The Timestamp.equals(Object) method never returns true when passed an object that isn’t an instance of java.sql.Timestamp , because the nanos component of a date is unknown. As a result, the Timestamp.equals(Object) method is not symmetric with respect to the java.util.Date.equals(Object) method. Also, the hashCode method uses the underlying java.util.Date implementation and therefore does not include nanos in its computation.

Due to the differences between the Timestamp class and the java.util.Date class mentioned above, it is recommended that code not view Timestamp values generically as an instance of java.util.Date . The inheritance relationship between Timestamp and java.util.Date really denotes implementation inheritance, and not type inheritance.

Constructor Summary

Method Summary

Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this Timestamp object.

Sets this Timestamp object to represent a point in time that is time milliseconds after January 1, 1970 00:00:00 GMT.

Obtains an instance of Timestamp from a LocalDateTime object, with the same year, month, day of month, hours, minutes, seconds and nanos date-time value as the provided LocalDateTime .

Methods declared in class java.util.Date

Methods declared in class java.lang.Object

Constructor Detail

Timestamp

@Deprecated(since="1.2") public Timestamp​(int year, int month, int date, int hour, int minute, int second, int nano)

Timestamp

public Timestamp​(long time)

Constructs a Timestamp object using a milliseconds time value. The integral seconds are stored in the underlying date value; the fractional seconds are stored in the nanos field of the Timestamp object.

Method Detail

setTime

public void setTime​(long time)

Sets this Timestamp object to represent a point in time that is time milliseconds after January 1, 1970 00:00:00 GMT.

getTime

Returns the number of milliseconds since January 1, 1970, 00:00:00 GMT represented by this Timestamp object.

valueOf

toString

Formats a timestamp in JDBC timestamp escape format. yyyy-mm-dd hh:mm:ss.fffffffff , where fffffffff indicates nanoseconds.

getNanos

setNanos

public void setNanos​(int n)

Источник