code: private static int computePointerSize()
      {
          String bits = System.getProperty("sun.arch.data.model");
          if (bits.equals("32"))
          {
              return 4;
          }
          else if (bits.equals("64"))
          {
              return 8;
          }
          else
          {
              System.err.println(
                  "Unknown value for sun.arch.data.model - assuming 32 bits");
              return 4;
          }
      }
docs: Computes the size of a pointer, in bytes
  
  @return The size of a pointer, in bytes