License3j is a Java library that can be used to create and
check license files. This way Java programs can enforce the
users to compensate their use of the software in the form of
a payment. This is the usual way when closed source programs
are distributed.
License management alone does not guarantee that the program
will not be stolen, pirated or used in any illegal way. However
license management may increase the difficulty to use the
program illegal and therefore may drive users to become
customers. There is another effect of license management, which
is legal. Using license management
illegal users have less probability to successfully claim their
use was based on the lack or false knowledge of license
conditions.
License3j is an open source license manager that you can use
free of charge. The license terms covered by
LGPL.