String to Cassandra Timestamp - java

I want to convert string date to Cassandra time stamp format
Example date
String inputDate="20170525"

You need to convert your string to Date.
Java Date type maps cassandra timestamp type
DateFormat dateFormat = new SimpleDateFormat("yyyyMMdd");
Date date = dateFormat.parse("20170525");
Now you have the date you can insert or query with it in prepared statement
Note : You don't have any timezone. So default timezone will be used. If you want to specify the timezone use dateFormat.setTimeZone(TimeZone zone) method

First, parse that input string as a LocalDate.
LocalDate ld = LocalDate.parse( "20170525" , DateTimeFormatter.BASIC_ISO_DATE ) ;
For a date-only value without time-of-day, you should be using type Date in Cassandra according to this documentation.
You can exchange data as strings using standard ISO 8601 format. The java.time classes use the standard formats by default. So no need to specify a formatting pattern.
String output = ld.toString() ;
2017-05-25
If you really want to store in the timestamp, you must specify a time-of-day. Perhaps you want the first moment of the day. Determining that specific moment on the timeline that requires a time zone. Do not assume the first moment occurs at 00:00:00. Anomalies such as Daylight Saving Time mean the time may be another value such as 01:00:00.
ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime zdt = ld.atStartOfDay( z ) ;
zdt.toString(): 2017-05-25T00:00:00-04:00[America/Montreal]
Cassandra stores the Timestamp field only as UTC. So we need to adjust the ZonedDateTime from our desired time zone to UTC. The easiest way to do that is extract a Instant. The Instant class is always in UTC by definition.
Instant instant = zdt.toInstant() ;
Generate a string in standard ISO 8601 format for Cassandra. Notice how the hour jumps from zero to four. Our time zone America/Montreal is four hours behind UTC on that date. So getting to UTC means adding four hours, 0 + 4 = 4.
String output = instant.toString() ;
2017-05-25T04:00:00Z
Going the other way when your retrieve this value.
Instant instant = Instant.parse( "2017-05-25T04:00:00Z" ) ;
ZonedDateTime zdt = instant.atZone( z );
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

Related

date is shown as fast milliseconds in java and not in proper format

I have the below declaration in java class
abc.setCreated(abcEntity.getCreatedDate());
and if I go deep inside the call inside abc entity
public Date getCreatedDate() {
return new Date(createdDate.getTime());
}
but the date in the outcome of
abc.setCreated(abcEntity.getCreatedDate());
shown as in request "created": 15704064000 and I want it to be shown as the date in DD-MM-YYYY format please advise how to achieve this
You can use SimpleDateFormat in java to get the date in that format. Instead of the time, pass the Date object like bellow.
ex:-
SimpleDateFormat simpleDateFormat = new SimpleDateFormat("dd-MM-yyyy");
String formattedDate = simpleDateFormat.format(new Date());
System.out.println(formattedDate);
tl;dr
Instant.
.ofEpochSecond(
1_570_406_400L
)
.atOffset(
ZoneOffset.UTC
)
.format(
DateTimeFormatter.ofPattern( "dd-MM-uuuu" )
)
07-10-2019
Avoid legacy classes
You are using terrible date-time classes that were supplanted years ago by the modern java.time classes.
java.time
Parse your count of whole seconds since the epoch reference of first moment of 1970 in UTC as a Instant.
Is your example value correct? Perhaps you meant 1,570,406,400.
long seconds = 1_570_406_400L ;
Instant instant = Instant.ofEpochMilli( seconds ) ;
The Instant represents a moment in UTC. Generate a string representing this value in standard ISO 8601 format.
String output = instant.toString() ;
instant.toString(): 2019-10-07T00:00:00Z
To adjust to another time zone, apply a ZoneId to get a ZonedDateTime.
ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime zdt = instant.atZone( z ) ;
zdt.toString(): 2019-10-06T20:00-04:00[America/Montreal]
Notice how the date is the 6th rather than the 7th. While at that moment a new day has begun in UTC, it is still “yesterday” in Canada. For any given moment, the date varies around the globe by time zone.
Generate a string a localized format.
DateTimeFormatter f = DateTimeFormatter.ofPattern( "dd-MM-uuuu" );
String output = zdt.format( f ) ;
output: 06-10-2019
If you want to report the date as seen in UTC rather than a time zone, use OffsetDateTime class. Specify UTC using the constant ZoneOffset.UTC.
OffsetDateTime odt = instant.atOffset( ZoneOffset.UTC ) ;
DateTimeFormatter f = DateTimeFormatter.ofPattern( "dd-MM-uuuu" );
String output = odt.format( f ) ;
outputOdt: 07-10-2019
See all that code run live at IdeOne.com.
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android bundle implementations of the java.time classes.
For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

Get Date from a DataObject (SDO) without losing the hour (JAVA)

I'm trying to get a date from a DataObject (Service Date Object (SDO)) that comes to me as an input and insert it into an Oracle database. The problem has been that the Date I get does not seem to have the introduced hour.
I am using the setDate() method from DataObject with the following value: 2019-05-22T13:30:00Z.
For some reason, when using getDate() what is returning is the day entered with the hour set at 0 (2019-05-22 00:00:00).
I'm not sure if it's due to the input format or something related to the Date class from java.utils.
An easy solution would be to pass it as String and convert it into Date using a format but I would like to save this intermediate step.
java.util.Date versus java.sql.Date
Your Question does not provide enough detail to know for sure, but I can take an educated guess.
returning is the day entered with the hour set at 0 (2019-05-22 00:00:00).
I suspect your code calling setDate and/or getDate is using a java.sql.Date object rather than a java.util.Date object.
➥ Check your import statements. If you used the wrong class by accident, that would explain the time-of-day getting set to 00:00.
java.util.Date represents a moment in UTC (a date, a time-of-day, and an offset-from-UTC of zero hours-minutes-seconds).
java.sql.Date pretends to represent a date-only, without a time-of-day and without a time zone or offset-from-UTC. Actually does contain a time-of-day and offset, but tries to adjust the time to 00:00:00.0 as part of the pretense.
Confusing? Yes. These old date-time classes from the earliest days of Java are a bloody awful mess, built by people who did not understand the complexities of date-time handling. Avoid these legacy date-time classes!
These legacy classes were supplanted years ago by the modern java.time classes defined in JSR 310. Try to do all your work in java.time. When interoperating with old code such as SDO that is not yet updated for java.time, call on new conversion methods added to the old classes.
The modern replacement of a java.util.Date is java.time.Instant. Both represents a moment in UTC, though Instant has a finer resolution of nanoseconds versus milliseconds.
Instant instant = Instant.now() ; // Capture the current moment in UTC.
Convert from modern class to legacy class. Beware of data-loss: Any microseconds or nanoseconds in the fractional second are truncated to milliseconds (as noted above).
java.util.Date d = java.util.Date.from( instant ) ; // Convert from modern to legacy. Truncates any microseconds or nanoseconds.
Pass to your SDO object.
mySdoDataObject.setDate( d ) ;
Going the other direction, retrieve the legacy java.util.Date object and immediately convert to an Instant.
Instant instant = mySdoDataObject.getDate().toInstant() ;
To see that same moment through the wall-clock time used by the people of a particular region (a time zone), apply a ZoneId to get a ZonedDateTime object.
ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime zdt = instant.atZone( z ) ; // Same moment, same point on the timeline, different wall-clock time.
An easy solution would be to pass it as String
No! Use smart objects, not dumb strings. We have the industry-leading date-time library built into Java, so use it.
Database
As of JDBC 4.2, we can directly exchange java.time objects with the database.
Your JDBC driver may optionally handle Instant. If not, convert to OffsetDateTime.
OffsetDateTime odt = instant.atOffset( ZoneOffset.UTC ) ;
myPreparedStatement.setObject( … , odt ) ;
Retrieval.
OffsetDateTime odt = myResultSet.getObject( … , OffsetDateTime.class ) ;
Instant instant = odt.toInstant() ;
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android bundle implementations of the java.time classes.
For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

Epoch_time_convertion_issue

My server is using GMT time zone but my application is working on IST, so I am converting GMT to IST while saving to database.But when I am converting this saved IST into epoch time then it's adding 5 hours 30 minutes into the saved IST time.
Is there any idea why? Am I doing anything wrong?
The code for converting GMT to IST:
public static Date convertGmtToIst(Date date) throws ParseException {
DateFormat converter = new SimpleDateFormat("dd-MM-yyyy:HH:mm:ss");
converter.setTimeZone(TimeZone.getTimeZone("IST"));
String dateReturns = converter.format(date);
SimpleDateFormat formatter = new SimpleDateFormat("dd-MM-yyyy:HH:mm:ss");
Date alteredDate = formatter.parse(dateReturns);
return alteredDate;
}
This is the code i am using to convert IST(2018-01-24 15:51:01) to epoch time.the date i am passing in this method is 2018-01-24 15:51:01 so this method should returns the epoch time of this date but it's adding 5 hours 30 minutes into this time.
public static long getEpochDateTime(Date date) {
long epochDateTime = date.getTime();
return epochDateTime;
}
tl;dr
Use smart objects, not dumb strings.
Instant.now().toEpochMilli()
Or:
myDate.toInstant().toEpochMilli()
Details
As discussed many times already on Stack Overflow…
My server is using GMT time zone
Never depend on the server OS settings for time zone. Always specify the optional time zone argument passed to the java.time classes’ methods.
converting GMT to IST while saving to database
Do most of your work in UTC. Adjust into another time zone only when business logic so dictates, or for presentation to user.
DateFormat converter = new SimpleDateFormat("dd-MM-yyyy:HH:mm:ss");
Work with date-time objects rather than mere strings.
Never use the troublesome Date and Calendar classes. Now supplanted by the java.time classes.
Never use 3-4 character pseudo-time zone codes such as IST. They are not true time zones, not standardized, and not even unique(!). Use true time zones in continent/region format.
ZoneId z = ZoneId.of( “Asia/Kolkata” ) ;
Get current moment in UTC.
Instant instant = Instant.now() ;
If your code must interoperate with Date, use new methods on old classes to convert to-and-fro.
Instant instant = myJavaUtilDate.toInstant() ;
Generate a string to represent this moment in standard ISO 8601 format by calling toString.
String output = instant.toString() ;
Adjust into another time zone. Same moment, same point on the timeline, different wall-clock time.
ZonedDateTime zdt = Instant.atZone( z ) ; // Same moment, different wall-clock time.
Call toString to generate a string with a format that wisely extends the ISO 8601 format by appending the name of the time zone in square brackets.
String output = zdt.toString() ;
To generate a string in other formats, see the DateTimeFormatter class.
You can move from a zoned moment to UTC by extracting an Instant.
Instant instant = zdt.toInstant() ;
returns the epoch time
Tracking time as a count-from-epoch is bad practice. But if you insist, you can extract a count of milliseconds from first moment of 1970 in UTC. Beware of data loss as Instant has a resolution of nanoseconds.
long millis = instant.toEpochMilli() ;
Get an Instant again. Again, I recommend against using a count-from-epoch, but if you insist.
Instant instant = Instant.ofEpochMilli( millis ) ;
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android bundle implementations of the java.time classes.
For earlier Android, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.
You should probably include timezone when serializing the date.
new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'");

Java Date Format Parsing

I am trying to change the date format from a JSON response, but I keep getting java.text.ParseException.
This is the date from the server 2015-02-03T08:37:38.000Z and I want it to show as 2015/02/03 That's yyyy-MM-dd. And I did this.
DateFormat df1 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
SimpleDateFormat dateFormatter = new SimpleDateFormat("yyyy-MM-dd");
String dateResp = transactionItem.get(position).getDate();
try {
Date date = df1.parse(dateResp);
transDate.setText(dateFormatter.format(date));
} catch (ParseException e) {
e.printStackTrace();
}
But the exception keeps showing.
You must escape the Z:
"yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"
Try to use this for formatting purpose instead of your provided formatting string. It should work nicely :)
tl;dr
Instant.parse( "2015-02-03T08:37:38.000Z" )
.atZone( ZoneId.of( "America/Montreal" ) )
.toLocalDate()
.toString() // 2015-02-03
Using java.time
The modern way to handle date-time work is with the java.time classes.
Your input string format happens to comply with the ISO 8601 standard. The java.time classes use ISO 8601 formats by default when parsing/generating strings that represent date-time values. So no need to specify a formatting pattern at all.
Parse that string as an Instant. The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction).
Instant instant = Instant.parse( "2015-02-03T08:37:38.000Z" ) ;
To extract a date, you must specify a time zone. For any given moment the date varies around the globe by zone. For example, a moment after midnight in Paris France is a new day while still “yesterday” in Montréal Canada.
ZoneId z = ZoneId.of( "America/Montreal" );
ZonedDateTime zdt = instant.atZone( z );
You want only the date portion without the time of day. So extract a LocalDate. While a LocalDate lacks any concept of offset-from-UTC or time zone, the toLocalDate method respects the ZonedDateTime object’s time zone in determining the date.
LocalDate ld = zdt.toLocalDate();
You seem to want standard ISO 8601 format, YYYY-MM-DD. Simply call toString without need to specify a formatting pattern.
String output = ld.toString();
2015-02-03
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
Where to obtain the java.time classes?
Java SE 8 and SE 9 and later
Built-in.
Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and SE 7
Much of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
The ThreeTenABP project adapts ThreeTen-Backport (mentioned above) for Android specifically.
See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

How can I tell if a Java Date and time zone is before the current time?

My class has 2 properties that make up its date:
java.util.Date date;
String timeZone;
How can I see if this date is before the current time on the server?
Basically I want to write something like this, but take timeZone into account:
return date.before(new Date());
Date stores internally as UTC, so your timeZone variable is not necessary. You can simply use Date.before(Date).
Calendar startCalendar = Calendar.getInstance();
int startTimeZoneOffset = TimeZone.getTimeZone(timeZone).getOffset(startDate.getTime()) / 1000 / 60;
startCalendar.setTime(startDate);
startCalendar.add(Calendar.MINUTE, startTimeZoneOffset);
Calendar nowCalendar = Calendar.getInstance();
int nowTimeZoneOffset = nowCalendar.getTimeZone().getOffset(new Date().getTime()) / 1000 / 60;
nowCalendar.setTime(new Date());
nowCalendar.add(Calendar.MINUTE, nowTimeZoneOffset);
return startCalendar.before(nowCalendar);
tl;dr
Use Instant class, which is always in UTC. So time zone becomes a non-issue.
someInstant.isBefore( Instant.now() )
java.time
The modern approach uses the java.time classes that supplanted the terrible Date & Calendar classes.
As the correct Answer by Kuo stated, your java.util.Date is recording a moment in UTC. So no need for a time zone.
Likewise, its replacement, the java.time.Instant class, also records a moment in UTC. So no time zone needed.
Instant instant = Instant.now() ; // Capture current in UTC.
So all you need as member variables on your class is Instant.
public class Event {
Instant when ;
…
}
To compare Instant objects, use the isAfter, isBefore, and equals methods.
someInstant.isBefore( Instant.now() )
For presentation in a time zone expected by the user, assign a ZoneId to get a ZonedDateTime object. The Instant and the ZonedDateTime both represent the same moment, the same point on the timeline, but viewed through different wall-clock time.
ZoneId z = ZoneId.of( "America/Montreal" ) ;
ZonedDateTime zdt = instant.atZone( z ) ; // Same moment, different wall-clock time.
String output = zdt.toString() ; // Generate text in standard ISO 8601 format, wisely extended to append the name of the zone in square brackets.
Or let java.time automatically localize output. To localize, specify:
FormatStyle to determine how long or abbreviated should the string be.
Locale to determine:
The human language for translation of name of day, name of month, and such.
The cultural norms deciding issues of abbreviation, capitalization, punctuation, separators, and such.
Example:
Locale l = Locale.CANADA_FRENCH ; // Or Locale.US, Locale.JAPAN, etc.
DateTimeFormatter f = DateTimeFormatter.ofLocalizedDateTime( FormatStyle.FULL )
.withLocale( l );
String output = zdt.format( f );
About java.time
The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.
The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.
To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.
You may exchange java.time objects directly with your database. Use a JDBC driver compliant with JDBC 4.2 or later. No need for strings, no need for java.sql.* classes.
Where to obtain the java.time classes?
Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
Java 9 adds some minor features and fixes.
Java SE 6 and Java SE 7
Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
Android
Later versions of Android bundle implementations of the java.time classes.
For earlier Android (<26), the ThreeTenABP project adapts ThreeTen-Backport (mentioned above). See How to use ThreeTenABP….
The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

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