8 Habits of Successful Java Developers

3 min readJan 6, 2025

Java developers, whether beginners or seasoned professionals, can greatly improve their craft by adopting key habits aligned with best practices. These eight essential habits are illustrated with code snippets that demonstrate SOLID principles and Java's core features:

1. Write Clean, Readable Code

Habit: Prioritize code readability using meaningful variable names, clear method signatures, and consistent formatting.

SOLID Principle: Single Responsibility Principle (SRP)

public class Invoice {
    private List<LineItem> items;

    public double calculateTotal() {
        return items.stream()
                    .mapToDouble(LineItem::getAmount)
                    .sum();
    }
}

Why?
The Invoice The class focuses solely on calculating the total and adhering to SRP.

2. Follow SOLID Principles

Habit: Design systems that are easy to maintain and extend by following SOLID principles.

Example: Open/Closed Principle (OCP)

public interface DiscountStrategy {
    double applyDiscount(double price);
}

public class PercentageDiscount implements DiscountStrategy {
    private final double percentage;    public PercentageDiscount(double percentage) {
        this.percentage = percentage;
    }    @Override
    public double applyDiscount(double price) {
        return price - (price * percentage / 100);
    }
}

Why?
You can introduce new discount strategies without modifying existing code, enhancing flexibility.

3. Use Robust Exception Handling

Habit: Manage errors gracefully by leveraging Java’s exception-handling framework.

Java Core Feature: Exception Hierarchy

public void processData() throws IOException {
    try (BufferedReader br = new BufferedReader(new FileReader("data.txt"))) {
        String line;
        while ((line = br.readLine()) != null) {
            // Process each line
        }
    } catch (IOException e) {
        throw new IOException("Failed to read file: " + e.getMessage(), e);
    }
}

Why?
The try-with-resources statement ensures efficient resource management and cleaner error handling.

4. Leverage Java 8+ Functional Features

Habit: Use lambda expressions and streams for concise, functional code.

Java Core Feature: Lambda Expressions and Streams

List<String> words = Arrays.asList("hello", "world", "java", "stream");
List<String> filteredWords = words.stream()
                                  .filter(word -> word.length() > 4)
                                  .collect(Collectors.toList());

Why?
Streams simplify operations like filtering, transforming, and collecting data.

5. Practice Test-Driven Development (TDD)

Habit: Write tests before or alongside your code to ensure functionality and catch bugs early.

SOLID Principle: Interface Segregation Principle (ISP)

public interface Shape {
    double area();
}

public class Circle implements Shape {
    private final double radius;    public Circle(double radius) {
        this.radius = radius;
    }    @Override
    public double area() {
        return Math.PI * radius * radius;
    }
}// Tests can validate the `area` method.

Why?
Smaller, specific interfaces make it easier to write precise and modular tests.

6. Optimize for Performance

Habit: Understand Java’s memory management and optimize where necessary.

Java Core Feature: Garbage Collection

List<String> results = new ArrayList<>(expectedSize);
for (int i = 0; i < expectedSize; i++) {
    results.add(someMethod());
}

Why?
Pre-allocating the list size reduces resizing operations and minimizes memory overhead.

7. Master Java’s Concurrency Utilities

Habit: Design thread-safe applications using Java’s concurrency features.

Java Core Feature: Concurrent Collections

ConcurrentHashMap<String, Integer> map = new ConcurrentHashMap<>();
map.putIfAbsent("key", 1); // Thread-safe operation

Why?
Using thread-safe collections like ConcurrentHashMap ensures safe access in multi-threaded environments.

8. Keep Learning and Updating

Habit: Stay up-to-date with the latest features in Java.

Java Core Feature: Modules (Java 9+)

module com.example.myapp {
    requires java.sql;
    exports com.example.myapp;
}

Why?
Modules improve modularity, allowing better dependency management and encapsulation.

Final Thoughts

These habits will lead to more maintainable, robust, and efficient software development. The key is not just knowing these principles but integrating them into daily coding practices. With continuous learning and practice, developers can elevate their Java expertise and deliver higher-quality solutions.