Implementation

In Java, an interface or the abstract type used to denote an interface must be implemented by classes. The interfaces that a certain class implements determine whether various aspects of these classes are "known" by another class, or what kinds of knowledge one class has about another.

One aspect of implementing an interface that can cause confusion is the requirement that to implement an interface, a class must implement all of the methods of that interface. This can lead to error messages due to insufficient implementation of methods. In general, the syntactical requirements of implementation and other Java tasks can be a burden for developers, and mastering this is part of becoming an in-depth Java user.