Nevermind....
public class MainClass {
public static void main(String[] args) {
java.util.Date utilDate = new java.util.Date();
java.sql.Date sqlDate = new java.sql.Date(utilDate.getTime());
System.out.println("utilDate:" + utilDate);
System.out.println("sqlDate:" + sqlDate);
}
}
explains it. The link is http://www.java2s.com/Tutorial/Java/0040__Data-Type/ConvertfromajavautilDateObjecttoajavasqlDateObject.htm
Answer from David Ackerman on Stack Overflowjava.util.Date vs java.sql.Date - Stack Overflow
jdbc - Get the current date in java.sql.Date format - Stack Overflow
mysql - A datetime equivalent in java.sql ? (is there a java.sql.datetime ?) - Stack Overflow
Modern SQL has nice features that are not available through JPA. Blaze-Persistence provides mappings for them.
Videos
Nevermind....
public class MainClass {
public static void main(String[] args) {
java.util.Date utilDate = new java.util.Date();
java.sql.Date sqlDate = new java.sql.Date(utilDate.getTime());
System.out.println("utilDate:" + utilDate);
System.out.println("sqlDate:" + sqlDate);
}
}
explains it. The link is http://www.java2s.com/Tutorial/Java/0040__Data-Type/ConvertfromajavautilDateObjecttoajavasqlDateObject.htm
tl;dr
How to convert java.util.Date to java.sql.Date?
Don’t.
Both Date classes are outmoded. Sun, Oracle, and the JCP community gave up on those legacy date-time classes years ago with the unanimous adoption of JSR 310 defining the java.time classes.
- Use java.time classes instead of legacy
java.util.Date&java.sql.Datewith JDBC 4.2 or later. - Convert to/from java.time if inter-operating with code not yet updated to java.time.
| Legacy | Modern | Conversion |
|---|---|---|
java.util.Date |
java.time.Instant |
java.util.Date.toInstant()java.util.Date.from( Instant ) |
java.sql.Date |
java.time.LocalDate |
java.sql.Date.toLocalDate()java.sql.Date.valueOf( LocalDate ) |
Example query with PreparedStatement.
myPreparedStatement.setObject(
… , // Specify the ordinal number of which argument in SQL statement.
myJavaUtilDate.toInstant() // Convert from legacy class `java.util.Date` (a moment in UTC) to a modern `java.time.Instant` (a moment in UTC).
.atZone( ZoneId.of( "Africa/Tunis" ) ) // Adjust from UTC to a particular time zone, to determine a date. Instantiating a `ZonedDateTime`.
.toLocalDate() // Extract a date-only `java.time.LocalDate` object from the date-time `ZonedDateTime` object.
)
Replacements:
Instantinstead ofjava.util.Date
Both represent a moment in UTC. but now with nanoseconds instead of milliseconds.LocalDateinstead ofjava.sql.Date
Both represent a date-only value without a time of day and without a time zone.
Details
If you are trying to work with date-only values (no time-of-day, no time zone), use the LocalDate class rather than java.util.Date.
java.time
In Java 8 and later, the troublesome old date-time classes bundled with early versions of Java have been supplanted by the new java.time package. See Oracle Tutorial. Much of the functionality has been back-ported to Java 6 & 7 in ThreeTen-Backport and further adapted to Android in ThreeTenABP.
A SQL data type DATE is meant to be date-only, with no time-of-day and no time zone. Java never had precisely such a class† until java.time.LocalDate in Java 8. Let's create such a value by getting today's date according to a particular time zone (time zone is important in determining a date as a new day dawns earlier in Paris than in Montréal, for example).
LocalDate todayLocalDate = LocalDate.now( ZoneId.of( "America/Montreal" ) ); // Use proper "continent/region" time zone names; never use 3-4 letter codes like "EST" or "IST".
At this point, we may be done. If your JDBC driver complies with JDBC 4.2 spec, you should be able to pass a LocalDate via setObject on a PreparedStatement to store into a SQL DATE field.
myPreparedStatement.setObject( 1 , localDate );
Likewise, use ResultSet::getObject to fetch from a SQL DATE column to a Java LocalDate object. Specifying the class in the second argument makes your code type-safe.
LocalDate localDate = ResultSet.getObject( 1 , LocalDate.class );
In other words, this entire Question is irrelevant under JDBC 4.2 or later.
If your JDBC driver does not perform in this manner, you need to fall back to converting to the java.sql types.
Convert to java.sql.Date
To convert, use new methods added to the old date-time classes. We can call java.sql.Date.valueOf(…) to convert a LocalDate.
java.sql.Date sqlDate = java.sql.Date.valueOf( todayLocalDate );
And going the other direction.
LocalDate localDate = sqlDate.toLocalDate();
Converting from java.util.Date
While you should avoid using the old date-time classes, you may be forced to when working with existing code. If so, you can convert to/from java.time.
Go through the Instant class, which represents a moment on the timeline in UTC. An Instant is similar in idea to a java.util.Date. But note that Instant has a resolution up to nanoseconds while java.util.Date has only milliseconds resolution.
To convert, use new methods added to the old classes. For example, java.util.Date.from( Instant ) and java.util.Date::toInstant.
Instant instant = myUtilDate.toInstant();
To determine a date, we need the context of a time zone. For any given moment, the date varies around the globe by time zone. Apply a ZoneId to get a ZonedDateTime.
ZoneId zoneId = ZoneId.of ( "America/Montreal" );
ZonedDateTime zdt = ZonedDateTime.ofInstant ( instant , zoneId );
LocalDate localDate = zdt.toLocalDate();
† The java.sql.Date class pretends to be date-only without a time-of-day but actually does a time-of-day, adjusted to a midnight time. Confusing? Yes, the old date-time classes are a mess.
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. Hibernate 5 & JPA 2.2 support java.time.
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 brought 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 (26+) bundle implementations of the java.time classes.
- For earlier Android (<26), a process known as API desugaring brings a subset of the java.time functionality not originally built into Android.
- If the desugaring does not offer what you need, the ThreeTenABP project adapts ThreeTen-Backport (mentioned above) to Android. 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.
Congratulations, you've hit my favorite pet peeve with JDBC: Date class handling.
Basically databases usually support at least three forms of datetime fields which are date, time and timestamp. Each of these have a corresponding class in JDBC and each of them extend java.util.Date. Quick semantics of each of these three are the following:
java.sql.Datecorresponds to SQL DATE which means it stores years, months and days while hour, minute, second and millisecond are ignored. Additionallysql.Dateisn't tied to timezones.java.sql.Timecorresponds to SQL TIME and as should be obvious, only contains information about hour, minutes, seconds and milliseconds.java.sql.Timestampcorresponds to SQL TIMESTAMP which is exact date to the nanosecond (note thatutil.Dateonly supports milliseconds!) with customizable precision.
One of the most common bugs when using JDBC drivers in relation to these three types is that the types are handled incorrectly. This means that sql.Date is timezone specific, sql.Time contains current year, month and day et cetera et cetera.
Finally: Which one to use?
Depends on the SQL type of the field, really. PreparedStatement has setters for all three values, #setDate() being the one for sql.Date, #setTime() for sql.Time and #setTimestamp() for sql.Timestamp.
Do note that if you use ps.setObject(fieldIndex, utilDateObject); you can actually give a normal util.Date to most JDBC drivers which will happily devour it as if it was of the correct type but when you request the data afterwards, you may notice that you're actually missing stuff.
I'm really saying that none of the Dates should be used at all.
What I am saying that save the milliseconds/nanoseconds as plain longs and convert them to whatever objects you are using (obligatory joda-time plug). One hacky way which can be done is to store the date component as one long and time component as another, for example right now would be 20100221 and 154536123. These magic numbers can be used in SQL queries and will be portable from database to another and will let you avoid this part of JDBC/Java Date API:s entirely.
LATE EDIT: Starting with Java 8 you should use neither java.util.Date nor java.sql.Date if you can at all avoid it, and instead prefer using the java.time package (based on Joda) rather than anything else. If you're not on Java 8, here's the original response:
java.sql.Date - when you call methods/constructors of libraries that use it (like JDBC). Not otherwise. You don't want to introduce dependencies to the database libraries for applications/modules that don't explicitly deal with JDBC.
java.util.Date - when using libraries that use it. Otherwise, as little as possible, for several reasons:
It's mutable, which means you have to make a defensive copy of it every time you pass it to or return it from a method.
It doesn't handle dates very well, which backwards people like yours truly, think date handling classes should.
Now, because j.u.D doesn't do it's job very well, the ghastly
Calendarclasses were introduced. They are also mutable, and awful to work with, and should be avoided if you don't have any choice.There are better alternatives, like the Joda Time API (
which might even make it into Java 7 and become the new official date handling API- a quick search says it won't).
If you feel it's overkill to introduce a new dependency like Joda, longs aren't all that bad to use for timestamp fields in objects, although I myself usually wrap them in j.u.D when passing them around, for type safety and as documentation.
A java.util.Date is not a java.sql.Date. It's the other way around. A java.sql.Date is a java.util.Date.
You'll need to convert it to a java.sql.Date by using the constructor that takes a long that a java.util.Date can supply.
java.sql.Date sqlDate = new java.sql.Date(utilDate.getTime());
These are all too long.
Just use:
new Date(System.currentTimeMillis())
The java.sql package has three date/time types:
java.sql.Date- A date only (no time part)java.sql.Time- A time only (no date part)java.sql.Timestamp- Both date and time
You want the last one: java.sql.Timestamp.
If you are using these types, you don't need to call a specific setter; just use:
java.util.Date date = new Date();
Object param = new java.sql.Timestamp(date.getTime());
// The JDBC driver knows what to do with a java.sql type:
preparedStatement.setObject(param);
The equivalent of MS SQL Server or MySQL DATETIME data type or Oracle DATE data type is java.sql.Timestamp.