Boolean.valueOf() produces NullPointerException sometimes

Question

I have this code:

package tests;

import java.util.Hashtable;

public class Tests {

    public static void main(String[] args) {

        Hashtable

        

Answer 1

Since modifiedItems.get returns a Boolean (which is not castable to a String), the signature that would be used is Boolean.valueOf(boolean), where the Boolean is outboxed to a primitive boolean. Once null is returned there, the outboxing fails with a NullPointerException.