Chapter 5.3, Problem 28STQ

Given the class Species as defined in Listing 5.19, why does the following program cause an error message?

public class SpeciesEqualsDemo

{

public static void main(String [] args)

{

Species s1, s2; s1;

setSpecies(“Klingon ox”, 10, 15);

s2.setSpecies(“Klingon ox”, 10, 15);

if (s1 == s2)

System.out.println(“Match with ==,”);

else

sysyem.out.println(“Do Not match with ==.”)

}

}