Simple testcase to determine if inner classes or lambdas take up more space

X.java

package foo;

public class X {
	public static final Runnable y = new Y();
	public static final Runnable z = new Z();

	static class Y implements Runnable {

		@Override
		public void run() {
			// TODO Auto-generated method stub
			System.out.println("Hello world");
		}

	}
	static class Z implements Runnable {

		@Override
		public void run() {
			// TODO Auto-generated method stub
			System.out.println("Hello again");
		}

	}
}

Z.java

package foo;

public class Z {
	public static final Runnable y = () -> System.out.println("Hello world");
	public static final Runnable z = () -> System.out.println("Hello again");

}

File sizes for the above:

Inner classes:

• 459 X$Y.class
• 459 X$Z.class
• 404 X.class

Lambdas:

• 1130 Z.class

Compiled with 1.8.0_60