{"id":84974,"date":"2024-01-29T09:16:36","date_gmt":"2024-01-29T09:16:36","guid":{"rendered":"https:\/\/www.baeldung.com\/convert-long-to-date-in-java"},"modified":"2024-01-29T09:16:36","modified_gmt":"2024-01-29T09:16:36","slug":"convert-long-to-date-in-java","status":"publish","type":"post","link":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/2024\/01\/29\/convert-long-to-date-in-java\/","title":{"rendered":"Convert Long to Date in Java"},"content":{"rendered":"

\"\"<\/p>\n

1. Overview<\/h2>\n
<\/div>\n

When working with dates in Java, we often see date\/time values expressed as long<\/em> values that denote the number of days, seconds, or milliseconds since the epoch<\/a>, January 1, 1970, 00:00:00 GMT.<\/p>\n

In this short tutorial, we’ll explore different ways of converting a long<\/em> value to a date in Java. First, we’ll explain how to do this using core JDK classes. Then, we’ll showcase how to achieve the same objective using the third-party Joda-Time library.<\/p>\n

2. Using the Java 8+ Date-Time API<\/h2>\n
<\/div>\n

Java 8 is often praised for the new Date-Time API feature it brought to the Java landscape. This API was introduced mainly to cover the drawbacks of the old date API. So, let\u2019s take a close look at what this API provides to answer our central question.<\/p>\n

2.1. Using the Instant<\/em> Class<\/h3>\n
<\/div>\n

The easiest solution would be using the Instant<\/em><\/a> class introduced in the new Java 8 date-time API<\/a>. This class describes a single instantaneous point on the timeline<\/strong>.<\/p>\n

So, let’s see it in practice:<\/p>\n

@Test\r\nvoid givenLongValue_whenUsingInstantClass_thenConvert() {\r\n    Instant expectedDate = Instant.parse("2020-09-08T12:16:40Z");\r\n    long seconds = 1599567400L;\r\n    Instant date = Instant.ofEpochSecond(seconds);\r\n    assertEquals(expectedDate, date);\r\n}<\/code><\/pre>\n
As shown above, we used the ofEpochSecond()<\/em> method to create an object of the Instant<\/em> class. Please bear in mind that we can use the ofEpochMilli()<\/em> method as well to create an Instant<\/em> instance using milliseconds.<\/p>\n
2.2. Using the LocalDate<\/em> Class<\/h3>\n
<\/div>\n
LocalDate<\/em><\/a> is another option to consider when converting a long<\/em> value to a date. This class models a classic date, such as 2023-10-17, without the time detail.<\/p>\n
Typically, we can use the LocalDate#ofEpochDay<\/em> method to achieve our objective:<\/p>\n
@Test\r\nvoid givenLongValue_whenUsingLocalDateClass_thenConvert() {\r\n    LocalDate expectedDate = LocalDate.of(2023, 10, 17);\r\n    long epochDay = 19647L;\r\n    LocalDate date = LocalDate.ofEpochDay(epochDay);\r\n    assertEquals(expectedDate, date);\r\n}<\/code><\/pre>\n
The ofEpochDay()<\/em> method creates an instance of the LocalDate<\/em> class from the given epoch day.<\/p>\n
3. Using the Legacy Date API<\/h2>\n
<\/div>\n
Before Java 8, we would usually use the Date<\/em> or Calendar<\/em> classes from the java.util<\/em> package to achieve our objective. So, let\u2019s see how to use these two classes to convert a long<\/em> value to a date.<\/p>\n
3.1. Using the\u00a0Date<\/em>\u00a0Class<\/h3>\n
<\/div>\n
The Date<\/em> class denotes a specific instant in time with millisecond precision. As the name indicates, it comes with a host of methods that we can use to manipulate dates. It offers the easiest way to convert a long<\/em> value to a date as it provides an overloaded constructor that accepts a parameter of long<\/em> type<\/strong>.<\/p>\n
So, let’s see it in action:<\/p>\n
@Test\r\nvoid givenLongValue_whenUsingDateClass_thenConvert() {\r\n    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");\r\n    dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));\r\n    Date expectedDate = dateFormat.parse("2023-10-15 22:00:00");\r\n    long milliseconds = 1689458400000L;\r\n    Date date = new Date(milliseconds);\r\n    assertEquals(expectedDate, date);\r\n}<\/code><\/pre>\n
Please note that the Date <\/em>class is outdated and belongs to the old API. So, it’s not the best way to go when working with dates.<\/p>\n
3.2. Using the Calendar<\/em> Class<\/h3>\n
<\/div>\n
Another solution would be to use the Calendar<\/em><\/a> class from the old date API. This class provides the setTimeInMillis(long value)<\/em> method that we can use to set the time to the given long<\/em> value<\/strong>.<\/p>\n
Now, let’s exemplify the use of this method using another test case:<\/p>\n
@Test\r\nvoid givenLongValue_whenUsingCalendarClass_thenConvert() {\r\n    SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");\r\n    dateFormat.setTimeZone(TimeZone.getTimeZone("UTC"));\r\n    Date expectedDate = dateFormat.parse("2023-07-15 22:00:00");\r\n    long milliseconds = 1689458400000L;\r\n    Calendar calendar = Calendar.getInstance();\r\n    calendar.setTimeZone(TimeZone.getTimeZone("UTC"));\r\n    calendar.setTimeInMillis(milliseconds);\r\n    assertEquals(expectedDate, calendar.getTime());\r\n}<\/code><\/pre>\n
Similarly, the specified long<\/em> value denotes the number of milliseconds passed since the epoch.<\/p>\n
4. Using Joda-Time<\/h2>\n
<\/div>\n
Lastly, we can use the Joda-Time library<\/a> to tackle our challenge. First, let’s add its dependency<\/a> to the pom.xml<\/em> file:<\/p>\n
<dependency>\r\n    <groupId>joda-time<\/groupId>\r\n    <artifactId>joda-time<\/artifactId>\r\n    <version>2.12.5<\/version>\r\n<\/dependency><\/code><\/pre>\n
Similarly, Joda-Time provides its version of the LocalDate<\/em> class. So, let’s see how we can use it to convert a long<\/em> value to a LocalDate<\/em> object:<\/p>\n
@Test\r\nvoid givenLongValue_whenUsingJodaTimeLocalDateClass_thenConvert() {\r\n    org.joda.time.LocalDate expectedDate = new org.joda.time.LocalDate(2023, 7, 15);\r\n    long milliseconds = 1689458400000L;\r\n    org.joda.time.LocalDate date = new org.joda.time.LocalDate(milliseconds, DateTimeZone.UTC);\r\n    assertEquals(expectedDate, date);\r\n}<\/code><\/pre>\n
As illustrated, LocalDate<\/em> offers a direct way to construct a date from a long<\/em> value.<\/p>\n
5. Conclusion<\/h2>\n
<\/div>\n
In this short article, we explained in detail how to convert a long<\/em> value to a date in Java.<\/p>\n
First, we’ve seen how to do the conversion using built-in JDK classes. Then, we illustrated how to accomplish the same goal using the Joda-Time library.<\/p>\n
As always, the code used in this article can be found over on GitHub<\/a>.<\/p>\n
\"\"<\/p>\n
<\/a> <\/a> <\/a> <\/a> <\/a> <\/a> <\/a> <\/div>\n\n
Commercials Cooperation Advertisements:<\/b><\/h2>\r\n

(1) IT Teacher IT Freelance
 <\/p>\r\nIT\u96fb\u8166\u88dc\u7fd2<\/a>
\u7acb\u523b\u8a3b\u518a\u53ca\u5831\u540d\u96fb\u8166\u88dc\u7fd2\u8ab2\u7a0b\u5427! <\/a>
\r\n\r\n\u7535\u5b50\u8ba1\u7b97\u673a -\u6559\u80b2 -IT \u96fb\u8166\u73ed\u201d ( IT\u96fb\u8166\u88dc\u7fd2 ) \u63d0\u4f9b\u4e00\u500b\u65b9\u4fbf\u7684\u7535\u5b50\u8ba1\u7b97\u673a \u6559\u80b2\u5e73\u53f0, \u70ba\u5927\u5bb6\u914d\u5c0d\u4fe1\u606f\u6280\u672f, \u96fb\u8166 \u8001\u5e2b, IT freelance \u548c programming expert. \u8b93\u5927\u5bb6\u65b9\u4fbf\u5730\u5c31\u80fd\u627e\u5230\u5408\u9069\u7684\u96fb\u8166\u88dc\u7fd2, \u96fb\u8166\u73ed, \u5bb6\u6559, \u79c1\u4eba\u8001\u5e2b.  
\r\n\r\nWe are a education and information platform which you can find a IT private tutorial teacher or freelance. 
\r\n\r\nAlso we provide different information about information technology, Computer, programming, mobile, Android, apple, game, movie, anime, animation\u2026 \r\n<\/p>\n

(2) ITSec
 <\/p>https:\/\/itsec.vip\/\r\nSecure<\/a> \r\n

 \r\n
www.ITSec.vip<\/a> 
 
 \r\n
www.Sraa.com.hk<\/a> 
 
 \r\n
www.ITSec.hk<\/a> 
 
 \r\n
www.Penetrationtest.hk<\/a> 
 
 \r\n
www.ITSeceu.uk<\/a> 
 
 \r\nSecure Your Computers from Cyber Threats and mitigate risks with professional services to defend Hackers. 

\r\nITSec provide IT Security and Compliance Services, including IT Compliance Services, Risk Assessment, IT Audit, Security Assessment and Audit, ISO 27001 Consulting and Certification, GDPR Compliance Services, Privacy Impact Assessment (PIA), Penetration test, Ethical Hacking, Vulnerabilities scan, IT Consulting, Data Privacy Consulting, Data Protection Services, Information Security Consulting, Cyber Security Consulting, Network Security Audit, Security Awareness Training. \r\n

Contact us right away. 

Email (Prefer using email to contact us): 
SalesExecutive@ITSec.vip<\/p>","protected":false},"excerpt":{"rendered":"
\"\"<\/p>\n
Learn to convert a long value to a date in Java using the Java 8 Date-Time API, the legacy Date API, and the Joda-Time library.<\/p>\n
<\/a>\u00a0<\/a>\u00a0<\/a>\u00a0<\/a>\u00a0<\/a>\u00a0<\/a>\u00a0<\/a>\u00a0<\/div>\n","protected":false},"author":293,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"site-container-style":"default","site-container-layout":"default","site-sidebar-layout":"default","disable-article-header":"default","disable-site-header":"default","disable-site-footer":"default","disable-content-area-spacing":"default","footnotes":""},"categories":[22],"tags":[61,122,127,129,124,128,125,132,131,133,126,130,123,66,94,88,97,56,64,65,60,112,40,75,95,104,33,120,22066,105,101,98,115,30,29,41,86,70,69,68,72,71,26,118,108,87,46,55,48,52,54,51,50,83,62,58,57,22065,22067,22068,109,35,59,63,85,79,82,96,80,27,81,114,44,42,43,45,38,39,110,117,100,111,116,73,89,90,92,91,93,84,78,37,102,34,36,77,67,74,99,113,119,28,121,32,47,49,53,103,31,76],"class_list":["post-84974","post","type-post","status-publish","format-standard","hentry","category-mobile","tag-airpods","tag-anime","tag-anime-characters","tag-anime-cosplay","tag-anime-edits","tag-anime-merchandise","tag-anime-movies","tag-anime-news","tag-anime-recommendations","tag-anime-reviews","tag-anime-series","tag-anime-streaming","tag-animes","tag-app-store","tag-app-store-samsung","tag-appgallery","tag-appgallery-oneplus","tag-apple","tag-apple-music","tag-apple-tv","tag-apple-watch","tag-bbc-sport","tag-best-mobile-games","tag-bixby","tag-bixby-xiaomi","tag-champions-league","tag-cyberpunk","tag-cyberpunk-2077","tag-date-conversions","tag-fantasy-football","tag-fifa","tag-football","tag-formula-1","tag-fortnite","tag-free-fire","tag-free-mobile-games","tag-freebuds-pro","tag-galaxy-a52","tag-galaxy-note-20","tag-galaxy-s21","tag-galaxy-watch-4","tag-galaxy-z-fold-3","tag-game","tag-games","tag-golf","tag-harmonyos","tag-how-to-backup-iphone","tag-how-to-factory-reset-iphone","tag-how-to-reset-iphone","tag-how-to-restore-iphone","tag-how-to-unlock-iphone","tag-how-to-unlock-iphone-5","tag-how-to-unlock-iphone-6","tag-huawei","tag-ios","tag-ipad","tag-iphone","tag-java-dates","tag-java-legacy-date-api","tag-joda-time","tag-live-soccer","tag-lol","tag-macbook","tag-macos","tag-mate-40-pro","tag-mi-11-lite","tag-mi-home-security-camera-basic-1080p","tag-mi-home-security-camera-basic-1080p-huawei","tag-mi-smart-band-6","tag-minecraft","tag-miui","tag-mlb-scores","tag-mobile-game-design","tag-mobile-game-development","tag-mobile-game-marketing","tag-mobile-game-monetization","tag-mobile-games","tag-mobile-gaming","tag-nba-scores","tag-nba-standings","tag-nfl","tag-nfl-scores","tag-nhl-scores","tag-one-ui","tag-oneplus","tag-oneplus-9-pro","tag-oneplus-buds-pro","tag-oneplus-nord-ce-5g","tag-oxygenos","tag-p40-pro-plus","tag-poco-x3-pro","tag-pokemon","tag-premier-league","tag-pubg","tag-pubg-mobile","tag-redmi-note-10-pro","tag-samsung","tag-samsung-pay","tag-soccer","tag-sports","tag-steam","tag-steeam","tag-top-10-anime","tag-valorant","tag-when-do-the-iphone-7-come-out","tag-when-does-the-iphone-7-come-out","tag-when-is-the-iphone-7-coming-out","tag-world-cup","tag-xbox-series-x","tag-xiaomi"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/posts\/84974","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/users\/293"}],"replies":[{"embeddable":true,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/comments?post=84974"}],"version-history":[{"count":1,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/posts\/84974\/revisions"}],"predecessor-version":[{"id":84975,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/posts\/84974\/revisions\/84975"}],"wp:attachment":[{"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/media?parent=84974"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/categories?post=84974"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gamefootballmobileanimeiphone.com\/index.php\/wp-json\/wp\/v2\/tags?post=84974"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}