Java Development and Refactoring Pro-Java Refactoring and Debugging

Example

Transforming a large method that handles multiple responsibilities into smaller, more manageable methods. This includes extracting methods, introducing design patterns such as Strategy to replace conditional logic, and renaming variables for clarity.

Scenario

In a banking software module, a single method handles customer data validation, transaction processing, and notifications. Refactoring involves breaking this method into several smaller ones, each handling one responsibility, thereby making the code easier to manage, test, and maintain.

Example

Identifying null pointer exceptions in a web application and fixing them by ensuring object references are properly checked before use.

Scenario

During the development of a CRM system, the application crashes frequently when certain user data is absent. The tool helps identify the root cause as a null pointer exception and resolves it by adding null checks and appropriate exception handling, thus stabilizing the application.

Example

Creating tests for a new API endpoint that calculates the monthly payments for different types of loans. Tests include scenarios covering various interest rates and loan amounts using JUnit 5 and Mockito to mock external dependencies like loan databases.

Scenario

For a financial application introducing new loan calculation features, unit tests are written to validate each calculation under expected and edge conditions, ensuring the API behaves as expected under all scenarios and is robust against invalid input values.