A.java

public class A {
    public static void main(String[] args) {
        A a = new A() {};
        System.out.println(a.getClass());
    }
}

gistfile1.java

public class A {
    private int a;
    public A() {}
    public void method() {
        System.out.println("A");
    }
}

public class B {
    A a = new A() { // anonymous subclass
        public void method() { System.out.println("AA"); }
    };
}

public class C {
    static int s;
    static { s = 1; } // static initializer

    private int i;
    { i = 2; } // instance initializer
}

public class D {
    List list = new ArrayList{ // anonymous subclass
        {add(0); add(1); add(2);} // instance initializer -> [0, 1, 2]
    };
}

Initializer.java

public class Initializer {
	private static String message = "I am Initializer.";
	private String name = "Initializer";
	
	static {
		System.out.println("Change message: " + message);
		message = "message is changed.";
	}
	
	{
		System.out.println("Change name: " + name);
		name = "new name";
	}
	
	public static void main(String[] args) {
		Initializer initializer = new Initializer();
		System.out.println("message: " + message +
				" name: " + initializer.name);
	}

}