The reason is that no computer s clock is perfect.
Using duration java measure wall clock time.
Java 8 brought us the new java time api which introduced several new types representing important time concepts.
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.
As these are designed for specific reasons it is important to choose the right one for your needs.
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.
This method can only be used to measure elapsed time and is not related to any other notion of system or wall clock time.
You ll now see how to calculate elapsed time using two of the new java time types.
Take a look at the following example.
The current date and time depend on the time zone and for globalized applications a time provider is necessary to ensure that the date and time are.
It is sometimes off and periodically needs to be corrected.
Following is the declaration for java io clock class.
Whenever possible use methods which measure only the processing time used by the current process.
Use of a clock is.
Measure elapsed time in java 8.
A clock providing access to the current instant date and time using a time zone.
The java time clock class provides access to the current instant date and time using a time zone.
As such a clock can be used instead of system currenttimemillis and timezone getdefault.
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.
If we re using java 8 we can try the new java time instant and java time duration classes.
Below java 8 proceed to next method down in the article.
Instead of the difference in system time between start and finish which could include time used by other processes on the computer.
Declaration following is the declaration for java time clock tick method.
To get the elapsed execution time in different.
The purpose of nanotime is to measure elapsed time and the purpose of currenttimemillis is to measure wall clock time.