Programming for beginners: TimeUnit constants

Friday, 7 March 2014

public static TimeUnit valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type.

Example

import java.util.concurrent.TimeUnit;
public class TimeUnitEx {
 public static void main(String args[]){
  TimeUnit Days = TimeUnit.valueOf("DAYS");
  System.out.println(Days);
  System.out.println(Days.toHours(1));
 }
}

Output

DAYS
24

Some Points to Remember

1. If the argument to the valuesOf is null, then NullPointerException thrown.

import java.util.concurrent.TimeUnit;
public class TimeUnitEx {
 public static void main(String args[]){
  TimeUnit Days = TimeUnit.valueOf(null);
 }
}

When you tries to run the above program, Java run time throws the NullPointerException.

Exception in thread "main" java.lang.NullPointerException: Name is null
 at java.lang.Enum.valueOf(Enum.java:235)
 at java.util.concurrent.TimeUnit.valueOf(TimeUnit.java:71)
 at TimeUnitEx.main(TimeUnitEx.java:14)
Java Result: 1

2. If the string passed to valueOf is not match with the TimeUnit constants, then IllegalArgumentException thrown.

import java.util.concurrent.TimeUnit;
public class TimeUnitEx {
 public static void main(String args[]){
  TimeUnit Days = TimeUnit.valueOf("ABCD");
 }
}

When you tries to run the above program, Java run time throws IllegalArgumentException

Exception in thread "main" java.lang.IllegalArgumentException: No enum constant java.util.concurrent.TimeUnit.ABCD
            at java.lang.Enum.valueOf(Enum.java:236)
            at java.util.concurrent.TimeUnit.valueOf(TimeUnit.java:71)
            at TimeUnitEx.main(TimeUnitEx.java:14)
Java Result: 1

https://self-learning-java-tutorial.blogspot.com/2014/03/values-return-all-timeunit-constants.html

https://self-learning-java-tutorial.blogspot.com/2014/03/valueof-return-timeunit-constant.html

https://self-learning-java-tutorial.blogspot.com/2014/03/convert-time-unit-conversion.html

https://self-learning-java-tutorial.blogspot.com/2014/03/other-time-conversion-methods.html

https://self-learning-java-tutorial.blogspot.com/2014/03/timeunit-sleep.html

https://self-learning-java-tutorial.blogspot.com/2014/03/timeunit-timedwait.html

https://self-learning-java-tutorial.blogspot.com/2014/03/timeunit-timedjoin.html

Get All TimeUnit constants TimeUnit Conversion Home

import java.util.concurrent.TimeUnit; public class TimeUnitEx { public static void main(String args[]){ TimeUnit[] t; t = TimeUnit.values(); System.out.println("The constants defined in TimeUnit Class are"); for(int i=0; i<t.length; i++) System.out.println(t[i]); } }

Programming for beginners

Friday, 7 March 2014

valueOf(): Return TimeUnit Constant

values : Return all TimeUnit constants