What Refactoring Techniques Can Improve the Performance of My Java Application?

What standard optimization refactoring techniques can I apply to my Java application to enhance its performance?

public class Sample {
    public static void main(String[] args) {
        int result = addNumbers(5, 10);
        System.out.println(result);
    }

    public static int addNumbers(int a, int b) {
        return a + b;
    }
}

Refactoring is a critical process in software development that allows you to improve the underlying structure of your code without altering its functionality. In Java applications, several optimization techniques can significantly boost performance and maintainability.

// Example of optimization through using StringBuilder
public class StringOptimization {
    public static void main(String[] args) {
        StringBuilder sb = new StringBuilder();
        for(int i=0; i<1000; i++) {
            sb.append(i);
        }
        String result = sb.toString();
        System.out.println(result);
    }
}

Causes

• Unnecessary object creation leading to high memory usage.
• Inefficient algorithms that increase execution time.
• Excessive coupling between classes that reduces modularity.
• Poor exception handling strategies adding overhead.

Solutions

• Reduce object creation by reusing objects when appropriate.
• Optimize algorithms by using appropriate data structures and methods.
• Improve code modularity by employing design patterns like Dependency Injection.
• Batch process operations to minimize the number of calls to expensive services.

Mistake: Failing to measure performance before and after refactoring.

Solution: Use profiling tools to assess where improvements can be made.

Mistake: Over-optimizing code prematurely.

Solution: Focus on clarity and maintainability first, then optimize.

Mistake: Neglecting the impact of refactoring on existing functionality.

Solution: Ensure thorough testing after refactoring.