InnerClassReferenceLeakActivity.java

public class InnerClassReferenceLeakActivity extends AppCompatActivity {

  /* 
   * Mistake Number 1: 
   * Never create a static variable of an inner class
   * Fix I:
   */
  private LeakyClass leakyClass;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_first);
        
        new LeakyClass(this).redirectToSecondScreen();

        /*
         * Inner class is defined here
         * */
         leakyClass = new LeakyClass(this);
         leakyClass.redirectToSecondScreen();
    }
  
  
    /*  
     * How to fix the above class:
     * Fix memory leaks:
     * Option 1: The class should be set to static
     * Explanation: Instances of anonymous classes do not hold an implicit reference to their outer class 
     * when they are "static".
     *
     * Option 2: Use a weakReference of the textview or any view/activity for that matter
     * Explanation: Weak References: Garbage collector can collect an object if only weak references 
     * are pointing towards it.
     * */
    private static class LeakyClass {
        
        private final WeakReference<Activity> messageViewReference;
        public LeakyClass(Activity activity) {
            this.activity = new WeakReference<>(activity);
        }
        
        public void redirectToSecondScreen() {
            Activity activity = messageViewReference.get();
            if(activity != null) {
               activity.startActivity(new Intent(activity, SecondActivity.class));
            }
        }
    }  
}

Line 40 should be this.messageViewReference = new WeakReference<>(activity), I guess.

I also agree with line 40 would has a problem