Implement CRUD Operations for Employee, Address, Department, and EmployeeDepartment with Postman Collection

[faizakram]

Summary:

This pull request adds complete CRUD operations and query methods for the following entities:

• Employee
• Address
• Department
• EmployeeDepartment

Changes Implemented:

1. Controllers Created:

   • EmployeeController
   • AddressController
   • DepartmentController
   • EmployeeDepartmentController

2. Services Created:

   • EmployeeService
   • AddressService
   • DepartmentService
   • EmployeeDepartmentService

3. Repositories Updated:

   • Added findBy methods for advanced querying based on relationships (e.g., find employees by department name, addresses by city, etc.)

4. Handled Infinite Recursion:

   • Used @JsonManagedReference and @JsonBackReference to prevent StackOverflowError during JSON serialization.

5. Postman Collection:

   • A comprehensive Postman collection is provided to test all the endpoints.

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Testing Instructions:

1. Run the application using Spring Boot.
2. Import the Postman collection located in the project directory.
3. Test all CRUD operations and findBy queries for each entity.

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Postman Collection Location:

https://github.com/faizakram/QuickStartSpringBoot/blob/feature/crud-operations-employee-address-department/postman/Complete_Employee_Management_System_API.postman_collection.json

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Notes:

• Ensure the database configuration in application.yml is correct before testing.
• All exceptions and edge cases for entity relationships have been handled.

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Reviewer Checklist:

• Verify CRUD operations for all entities.
• Test advanced findBy queries.
• Check JSON serialization handling (no infinite recursion).
• Ensure all endpoints in the Postman collection are functional.