Create WeakReferece out of the inner class!

Www.java

import java.lang.ref.WeakReference;

public class Www {
    public static void main(String args[]) {
        Runnable r0 = create0();
        Runnable r1 = create1();

        System.gc();
        r0.run();
        r1.run();
    }

    static Runnable create0() {
        Www w = new Www();

        WeakReference<Www> ref = new WeakReference<>(w);

        return
            new Runnable() {
                public void run() {
                    System.out.println("0 " + ref.get());
                }
            };
    }

    static Runnable create1() {
        Www w = new Www();
        return
            new Runnable() {
                WeakReference<Www> ref = new WeakReference<>(w);
                
                public void run() {
                    System.out.println("1 " + ref.get());
                }
            };
    }
}