/**
* Returns the value that corresponds to a given implementation calculator class.
*
* @param clazz the target class.
* @throws IllegalArgumentException if {@code clazz} is {@code null} or if it is abstract.
* @return never {@code null}.
*/
public static AFCalculatorImplementation fromCalculatorClass(
final Class<? extends AFCalculator> clazz) {
Utils.nonNull(clazz, "input class cannot be null");
Utils.validateArg(
!Modifier.isAbstract(clazz.getModifiers()),
"class " + clazz.getCanonicalName() + " should not be abstract");
// Using iteration instead of a static map to avoid static state.
for (final AFCalculatorImplementation impl : AFCalculatorImplementation.values()) {
if (clazz.equals(impl.newInstance().getClass())) {
return impl;
}
}
throw new IllegalArgumentException(
"Attempt to retrieve AFCalculatorImplementation instance from a non-registered calculator class "
+ clazz.getName());
}
/**
* Transforms and composes the string representation of an individual count.
*
* <p>The output string must be fully formatted human friendly representation of the transformed
* value.
*
* @param count the individual count value.
* @param columnTotal the corresponding column total sum.
* @return never {@code null}.
* @throws IllegalArgumentException if {@code count} is less than 0 or greater than {@code
* columnTotal}.
*/
protected String apply(final int count, final long columnTotal) {
ParamUtils.isPositiveOrZero(count, "the count cannot less than 0");
Utils.validateArg(count <= columnTotal, "the count cannot be larger than the column total");
return operator.apply(count, columnTotal);
}