In Java, nested classes are categorized as either static member classes or inner classes. Inner classes are non-static member classes, local classes, or anonymous classes.

Starting with JDK 1.1, Java provided the ability to create nested classes. A nested class is defined inside another class. There are two types of nested classes: static nested classes and inner ...

From a maintenance point of view, inexperienced Java developers may find the inner class difficult to understand. The use of inner classes will also increase the total number of classes in your code.