public byte byteValueExact() {
       long num;
       num = this.longValueExact();     // will check decimal part
       if ((byte)num != num)
           throw new java.lang.ArithmeticException("Overflow");
       return (byte)num;
    }
public byte byteValueExact ( ) { long num ; num = this . longValueExact ( ) ; if ( ( byte ) num != num ) throw new java . lang . ArithmeticException ( "Overflow" ) ; return ( byte ) num ; }
Converts this {@code BigDecimal} to a {@code byte}, checking
for lost information.  If this {@code BigDecimal} has a
nonzero fractional part or is out of the possible range for a
{@code byte} result then an {@code ArithmeticException} is
thrown.

@return this {@code BigDecimal} converted to a {@code byte}.
@throws ArithmeticException if {@code this} has a nonzero
fractional part, or will not fit in a {@code byte}.
@since  1.5