Java library with Maven.

what it does for now:
to transform BigInteger to BigDecimal (you specify where the period goes; if you enter an invalid number, BigDecimal = BigInteger)
and vice versa from BigDecimal to BigInteger, e.g., 123,456 to 123,456

dependence:

<dependency>
 <groupId>com.leibnix</groupId>
 <artifactId>utilities-bigdecimal-biginteger</artifactId>
 <version>0.0.1</version>
</dependency>

link: https://central.sonatype.com/artifact/com.leibnix/utilities-bigdecimal-biginteger

It’s not in maven-central yet because I just published it, but you can use it if you add the dependency to your pom.

the repository is https://gitlab.com/com.leibnix/utilities-bigdecimal-biginteger

The license is Creative Commons Zero, that is, CC0.