Let's Summarize

In the previous video, you might have heard that the foundation of our project is ready, and we already know the basic principles of Hibernate.

In this chapter, I'll also provide a brief summary of what we have learned, what we are capable of, and how our project works.

Let's start from the beginning: The goal of our project is an employee management system in a company. Such a project would be beneficial to any manager or supervisor in the company. Such a manager should be able to add new employees, update their information, transfer them between departments, make changes to an employee's salary, and, of course, view comprehensive information about each employee.

In this course, we established a connection with the database for this project and implemented most of the necessary operations. We worked within a three-layered application, implementing the DAO and service layers.

On this foundation, further application development will be built. But for now, let's review the entity classes and recall how they work:

Database

Let's start with our lowest layer, which is the database integration layer. This layer is represented by DAO interfaces and the classes that implement them.

We have DAO interfaces for each model:

EmployeeDao;
DepartmentDao;
RoleDao;
TaskDao.

Each of these interfaces handles interaction with the database for a specific model.

They contain basic CRUD operations ( except for the delete operation, which we implement in the next courses ). Based on this, we can add, read, and update each of our models.

Service

Next comes the service layer, which implements various business logic, such as changing an employee's salary, assigning tasks, and so on.

The service layer also implements all methods from the database layer.

Here is the EmployeeService interface, which shows all the methods we outlined for this model:

Controller

For the controller layer, we had the Main class, where we tested the program's execution by performing various operations described at the Service layer.

You will learn about what will happen at the controller layer and how we will implement it in the next chapter.