The Cost of Erasure in Java Generics Type System

Java generics, found in versions 1.5 and later, are implemented by generating only one byte code representation of a generic type or method; a compiler maps all the instantiations of a generic type or method to that unique representation via type erasure. The essence of type erasure is the removal during compilation of all information that is related to type parameters and type arguments. From the point of view of the programmer, (s)he is left to negotiate a series of compiler and run-time errors that have little to do with programming errors but a lot to do with the Java generics implementation choice and leaving programmer sometimes with no choice but to live with unclean compiles.