Convert string "yyyy-MM-dd" to LocalDateTime

Question

Is there a way to convert a String date to LocalDateTime , where the format is "yyyy-MM-dd" ?

If I try this:

 DateTimeFormatter DATEFORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd"); LocalDateTime ldt = LocalDateTime.parse(string, DATEFORMATTER); 

I got this exception:

 java.time.format.DateTimeParseException: Text '2017-03-13' could not be parsed: Unable to obtain LocalDateTime from TemporalAccessor: {},ISO resolved to 2017-03-13 of type java.time.format.Parsed at java.time.format.DateTimeFormatter.createError(DateTimeFormatter.java:1920) at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1855) at java.time.LocalDateTime.parse(LocalDateTime.java:492) at hu.npsh.workforce.utils.Util.stringToLocalDateTime(Util.java:284) at hu.npsh.workforce.utils.util.StringLocalDateTimeConversionTest.stringToLocalDateTimeTest(StringLocalDateTimeConversionTest.java:35) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:50) at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12) at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:47) at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17) at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:325) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:78) at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:57) at org.junit.runners.ParentRunner$3.run(ParentRunner.java:290) at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:71) at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:288) at org.junit.runners.ParentRunner.access$000(ParentRunner.java:58) at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:268) at org.junit.runners.ParentRunner.run(ParentRunner.java:363) at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:86) at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:459) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:678) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:382) at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:192) Caused by: java.time.DateTimeException: Unable to obtain LocalDateTime from TemporalAccessor: {},ISO resolved to 2017-03-13 of type java.time.format.Parsed at java.time.LocalDateTime.from(LocalDateTime.java:461) at java.time.format.Parsed.query(Parsed.java:226) at java.time.format.DateTimeFormatter.parse(DateTimeFormatter.java:1851) ... 26 more Caused by: java.time.DateTimeException: Unable to obtain LocalTime from TemporalAccessor: {},ISO resolved to 2017-03-13 of type java.time.format.Parsed at java.time.LocalTime.from(LocalTime.java:409) at java.time.LocalDateTime.from(LocalDateTime.java:457) ... 28 more 

I know that the main problem is that the template does not contain an hour and a minute. But what if I want to create a method that gets String and DateTimeFormatter , and I want to return using LocalDateTime

Is there a right, nice solution?

EDIT:

My goal is to make a method, get a String and DateTimeFormatter AND return with LocalDateTime . The template can be anything (which is true).

Answer 1

Use LocalDate to create a localDate, and then you can add a temporary part if you need one:

  DateTimeFormatter DATEFORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd"); LocalDate ld = LocalDate.parse("2017-03-13", DATEFORMATTER); LocalDateTime ldt = LocalDateTime.of(ld, LocalDateTime.now().toLocalTime()); System.out.println(ldt); 

or LocalDateTime

 ldt = LocalDateTime.of(ld, LocalDateTime.MIN.toLocalTime()); 

if you just need an empty period of time

EDIT:

Look at this solution with the help of this you can build your dynamic parser:

  DateTimeFormatter DATEFORMATTER1 = DateTimeFormatter.ofPattern("yyyy-MM-dd"); DateTimeFormatter DATEFORMATTER = new DateTimeFormatterBuilder().append(DATEFORMATTER1) .parseDefaulting(ChronoField.HOUR_OF_DAY, 0) .parseDefaulting(ChronoField.MINUTE_OF_HOUR, 0) .parseDefaulting(ChronoField.SECOND_OF_MINUTE, 0) .toFormatter(); //DateTimeFormatter DATEFORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd"); LocalDateTime ldt = LocalDateTime.parse("2017-03-13", DATEFORMATTER); 

Answer 2

You cannot convert "2017-03-13" to LocalDateTime , since the line does not contain only time information, but only date. You can convert it to LocalDate

 DateTimeFormatter dateformatter = DateTimeFormatter.ofPattern("yyyy-MM-dd"); LocalDate ld = LocalDate.parse("2017-03-13", dateformatter); 

after that we can hide it until LocalDateTime

 LocalDateTime ldt = ld.atStartOfDay(); 

Answer 3

To start the day you can use:

 LocalDate.parse("2017-10-18", DateTimeFormatter.ofPattern("yyyy-MM-dd")) .atStartOfDay().atOffset(ZoneOffset.UTC).format(DateTimeFormatter.ISO_DATE_TIME) 

At the end of the day you can use:

 LocalDate.parse("2017-10-18", DateTimeFormatter.ofPattern("yyyy-MM-dd")) .atStartOfDay().plusHours(23).plusMinutes(59).plusSeconds(59).atOffset(ZoneOffset.UTC).format(DateTimeFormatter.ISO_DATE_TIME) 

For localDateTime you can use:

 LocalDate.parse("2017-10-18", DateTimeFormatter.ofPattern("yyyy-MM-dd")).atTime(LocalTime.now()) .atOffset(ZoneOffset.UTC).format(DateTimeFormatter.ofPattern("yyyy-MM-dd'T'HH:mm:ss'Z'")) 

Result:

 2017-10-18T00:00:00Z 2017-10-18T23:59:59Z 2017-10-18T14:45:35Z 

Answer 4

How about one liner?

 LocalDateTime.parse("2017-03-13", DateTimeFormatter.ofPattern("yyyy-MM-dd")); 

Answer 5

Use Joda-Time-XX.jar to be able to DateTimeFormatter convert date and date format. Either you can specify the date in (yyyy-MM-dd HH: mm: ss format) or date alone. In both cases, you will receive the date and time.

 DateTimeFormatter dateTimeFormatter = DateTimeFormat.forPattern("yyyy-MM-dd"); DateTime dateTime = dateTimeFormatter.parseDateTime(date);