Checks for illegal instantiations where a factory method is preferred. Depending on the project, for some classes it might be preferable to create instances through factory methods rather than calling the constructor. A simple example is the java.lang.Boolean
class. In order to save memory and CPU cycles, it is preferable to use the predefined constants TRUE and FALSE. Constructor invocations should be replaced by calls to Boolean.valueOf()
. Some extremely performance sensitive projects may require the use of factory methods for other classes as well, to enforce the usage of number caches or object pools.