What are the differences between Helper and Utility classes?

java

singleton

best-practices

design-patterns

byAlex Kataev·Mar 10, 2025

Helper classes are pertinent in context, holding state to provide specialized assistance. On the contrary, Utility classes are stateless, house static methods, and offer general solutions without requiring context.

Example:

// Utility class: much like the unsung hero of code, busy doing housekeeping!
public final class MathUtils {
    private MathUtils() {} // I'm like 'The Room of Requirement' in Harry Potter. You don't visit me, I come to you!

    public static int add(int a, int b) {
        return a + b; // as simple as apple pie!
    }
}

// Helper class: your personal assistant to sort arrays!
public class SortingHelper {
    private int[] numbers;

    public SortingHelper(int[] numbers) {
        this.numbers = numbers.clone();
    }

    public void sortArray() {
        Arrays.sort(numbers); // Sorting like a champ!
    }
}

The Yin and Yang of Helper and Utility classes

Utility classes: The Swiss Army knife

Static: composed of static methods that can be borrowed anywhere without object instantiation.
Selfless: by being final and harboring a private constructor, they prevent self-creation and inheritance.
Versatile: perform a variety of unrelated tasks, making them a multipurpose tool.

Helper classes: The Specialized toolset

Stateful: they hold state, providing context-specific assistance to particular tasks.
Tailored: designed to simplify or encapsulate complicated tasks, usually used in conjunction with another class.
Utilitarian: although not universally applicable like Utility classes, Helpers optimize operations in their domain.

Intelligent design: Naming and structuring

Utility classes: The Dictionary

Utility classes are akin to dictionaries, generalized yet purposeful. They reside in a util package and have a "Utils" suffix.

Example:

package com.example.util; // the "dictionary" aisle

public final class StringUtils { // Your "lexical magic wand"
    public static boolean isNullOrEmpty(String string) {
        return string == null || string.isEmpty(); // Catching emptiness, one string at a time!
    }
}

Helper classes: The User Manual

Helper classes are context-specific and are named accordingly. They live close to where they're needed.

Example:

package com.example.session; // close to home

public class SessionHelper { // The "guardian spirit" of the session
    private Session session;

    public SessionHelper(Session session) {
        this.session = session;
    }

    // An "inside knowledge" function
    public User getCurrentUser() {
        return session.getCurrentUser(); // It's good to know your user!
    }
}