functional programming

“`java
import java.util.function.Predicate;

// Assuming this is part of a class where ‘order’ is passed to a method, e.g., processOrder(Order order)

if (!validateOrder(order)) {
System.out.println(“Order validation failed for: ” + order.getOrderId());
return;
}

private boolean validateOrder(Order order) {
// Using Java 8 functional programming with Predicates for composability
Predicate hasPositiveAmount = o -> o.getTotalAmount() > 0;
Predicate hasNonEmptyItems = o -> !o.getItems().isEmpty();

// Combine predicates functionally (can chain more if needed)
Predicate orderValidator = hasPositiveAmount.and(hasNonEmptyItems);

return orderValidator.test(order);
}
“`

This approach leverages Java 8’s functional features by using `Predicate` lambdas, which are composable with methods like `and()`, `or()`, and `negate()`. This makes the validation more modular and easier to extend with additional checks without changing the structure. The main `if` logic remains imperative for control flow (as returning from a method is not directly achievable in a pure functional style within lambdas), but the validation itself is now functional. If you provide more context or additional validations, I can refine it further!