Refactoring is the process of improving the structure, readability, and maintainability of code without changing its functionality. As Java developers, it is essential to regularly refactor our code to ensure its quality and adaptability. Here are some best practices to follow for code refactoring in Java JDK projects.

1. Plan your refactoring

Before starting a refactoring process, it is essential to have a well-defined plan. Identify the specific areas or code blocks that need improvement and set goals for the refactoring process. This will help you stay focused and ensure that you don’t introduce new bugs or unintended consequences.

2. Understand the code

Before making any changes, it is crucial to thoroughly understand the code you are refactoring. Identify any dependencies, potential side effects, and ensure you have a clear understanding of the intended behavior. Refactoring without understanding the code can lead to unexpected issues and make debugging more challenging.

3. Break down large methods

If you encounter large methods that are difficult to understand or maintain, it’s a good practice to break them down into smaller, more manageable methods. This improves code readability, enables better code reusability, and makes troubleshooting and debugging easier.

public void processOrder(Order order) {
    // long and complex logic
}

Refactored code:

public void processOrder(Order order) {
    validateOrder(order);
    updateInventory(order);
    createInvoice(order);
    // other logical steps
}

4. Use meaningful variable and method names

Clear and meaningful variable and method names contribute to the readability and maintainability of the code. Avoid using vague names like “temp” or “var1”. Instead, use descriptive names that accurately reflect the purpose or behavior of the variable or method.

int x;  // Avoid using vague names like x

Refactored code:

int numberOfStudents;

5. Reduce code duplication

Code duplication not only increases the size of the codebase but also makes maintenance and bug fixing difficult. Identify duplicated code segments and extract them into reusable methods or utility classes. This promotes modularity, reduces redundancy, and improves the overall quality of the code.

public void methodA() {
    // common code block
    // specific logic for methodA
}
public void methodB() {
    // common code block
    // specific logic for methodB
}

Refactored code:

public void commonMethod() {
    // common code block
}
public void methodA() {
    commonMethod();
    // specific logic for methodA
}
public void methodB() {
    commonMethod();
    // specific logic for methodB
}

6. Refactor in small steps

Instead of attempting to refactor large portions of code in a single go, it is advisable to break it down into smaller, manageable steps. This minimizes the risk of introducing new bugs and allows for continuous integration and deployment. Test the code after each refactoring step to ensure that everything is functioning as expected.

7. Have comprehensive test coverage

Code refactoring can introduce unforeseen bugs or regressions. Having comprehensive unit tests ensures that the code behaves as intended before and after refactoring. Run the tests after each refactoring step to catch any issues early on and maintain the stability of your codebase.

#java #refactoring