Am I misusing HashMap or just need to fix the .hashCode() override for the
key object?

The class I use as a key for a HashMap is unique based on a combination of 4
ints.  Normally,  about 5000 instances are created and persist over time.
The maximum possible created is probably max around 40,000.

Since .hashCode() returns an int, how do I create a unique identifier for
the 128 bits contained in the 4 ints? Or should I swap to another data
structure?

Thanks!

// Here's a simplification of my class that illustrates my problem.

public class IntHashExample {
   int A, B, C, D;

   IntHashExample( int A , int B , int C , int D ) {
       this.A = A;
       this.B = B;
       this.C = C;
       this.D = D;
   }

   public boolean equals( Object arg0 ) {

       IntHashExample other = ( IntHashExample ) arg0;

       if ( ( A == other.A ) && ( B == other.B ) && ( C == other.C ) && ( D
== other.D ) )
           return true;
       else
           return false;
   }

   // how do I create a hashcode to lookup the unique combination of the 4
ints? The following obviously wouldn't work,
   // but hopefully indicates my need
   public int hashCode() {

       long highest = ( long ) A << 96;

       long high = ( long ) B << 64;

       long low = ( long ) C << 32;

       long lowest = ( long ) D;

       int code = ( int ) ( highest | high | low | lowest );

       return code;
   }
}