"Practices For Writing EJB Applications"
Vol. 6, Issue 4, p. 12

	




Listing 1

public final class EmployeePK implements java.io.Serializable {


  public String lastName;
  public String firstName;
  public int officeNumber;


  private int hash = -1;


  public EmployeePK() {}


  public int hashCode() {
    if (hash == -1) {
      hash = lastName.hashCode() ^ firstName.hashCode()
       ^ officeNumber;
    }
    return hash;
  }
  public boolean equals(Object o) {
    if (o == this) return true;


    if (o instanceof EmployeePK) {
      EmployeePK other = (EmployeePK) o;
      return other.hashCode() == hashCode() &&
             other.officeNumber == officeNumber &&
             other.lastName.equals(lastName) &&
             other.firstName.equals(firstName);


    } else {
      return false;
    }
  }
 }