Kacheck/J is an encapsulation checker for Java. It infers which types are confined according to the definition given in Encapsulating Objects with Confined Types. Objects of confined type do not escape their enclosing package. Confined types allow you to increase the modularization of your code. Since objects of confined type to not escape their defining package, it is certain that no code outside of the package will directly depend on the interface or implementation of the confined type. Kacheck/J allows you to analyze your code for confinement and can print a list of statements that lead to confinement violations. Confined types are also interesting from a security perspective since they can guarantee that access to certain data-structures is only possible for code in the same package.
