Java 8 brought us the new java time api which introduced several new types representing important time concepts.
Using duration java measure wall clock time.
As these are designed for specific reasons it is important to choose the right one for your needs.
You ll now see how to calculate elapsed time using two of the new java time types.
Measure elapsed time in java 8.
Use of a clock is.
Learn to calculate execution time or measure elapsed time of a program or some java statements using system nanotime or system currenttimemillis methods.
Public abstract class clock extends object class constructors.
Below java 8 proceed to next method down in the article.
If we re using java 8 we can try the new java time instant and java time duration classes.
Clock was added in java 8 and provides access to an instant in time using the best available system clock and to be used as a time provider which can be effectively stubbed for testing purposes.
The java time clock class provides access to the current instant date and time using a time zone.
The instant and the duration classes.
The purpose of nanotime is to measure elapsed time and the purpose of currenttimemillis is to measure wall clock time.
The java time clock tick method obtains a clock that returns instants from the specified clock truncated to the nearest occurrence of the specified duration.
Instances of this class are used to find the current instant which can be interpreted using the stored time zone to find the current date and time.
To get the elapsed execution time in different.
The reason is that no computer s clock is perfect.
As such a clock can be used instead of system currenttimemillis and timezone getdefault.
This method can only be used to measure elapsed time and is not related to any other notion of system or wall clock time.
Take a look at the following example.
Instead of the difference in system time between start and finish which could include time used by other processes on the computer.
Following is the declaration for java io clock class.
Declaration following is the declaration for java time clock tick method.
Write a program which uses a timer with the least granularity available on your system to time how long a function takes to execute.
Another method in java lang system class is nanotime if we look at the java documentation we ll find the following statement.
Whenever possible use methods which measure only the processing time used by the current process.
