Learn about Java anonymous classes.
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Deep Dive into Inner and Nested Classes in Java
Anonymous Classes in Java
java - Netbeans fails to find main class when creating anonymous subclass of inner class of anonymous subclass - Stack Overflow
Anonymous Class In Java - Coding Ninjas
Diamond operator for Anonymous Inner Classes, by Rajat Mishra, Xebia Engineering Blog
Write an Anonymous Inner Class in Java
Working With Nested Class in Java
Quiz yourself: Anonymous inner classes in Java
Diamond Operator With Anonymous Inner Class - java4coding
Why does javac create PanelTest$1.class and PanelTest$2.class when I compile PanelTest.Java? Can we delete the $.* files? - Quora
Anonymous Class Using Thread
Java Anonymous Inner Classes and Effectively Final variables, by Meenakshisundaram