factorial method library in java
2.4. Factorial Using Apache Commons Math
Apache Commons Math has a CombinatoricsUtils class with a static factorial method that we can use to calculate the factorial.
To include Apache Commons Math, we'll add the commons-math3 dependency into our pom:
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-math3</artifactId>
<version>3.6.1</version>
</dependency>
Let's see an example using the CombinatoricsUtils class:
public long factorialUsingApacheCommons(int n) {
return CombinatoricsUtils.factorial(n);
}