1. Find the statement that causes the compilation error.2. Determine the output if that statement is removed.class A public void test() System.out.print("A");class B extends A public void test() System.out.print("B");public class C extends A public void test() System.out.print("C");public static void main(String[] args) A b1 = new A();A b2 = new C();b1 = (A)b2;A b3 = (B)b2;b1.test();b2.test();

How to Solve java.lang.NullPointerException Error

Como resolver esse erro de java.lang.NullPointerException