Spring Boot Demo 3

This exercise guides you through building the Web Layer (the "Controller" and "View" components) of a Spring Boot application using the MVC (Model-View-Controller) architecture. It focuses on integrating user interface templates with the data layer created in previous steps.

The key objectives of this part of the tutorial are:

1. Dependency Management

• Integrating Thymeleaf: Adding the spring-boot-starter-thymeleaf dependency to the pom.xml file to enable the use of HTML templates.

• Adding Validation: Including spring-boot-starter-validation to handle data integrity and error checking for user inputs.

• Maven Project Reloading: Demonstrating how to refresh the project in IntelliJ IDEA to download and apply these new libraries.

2. View Development (The "V" in MVC)

• Creating a Main Menu: Developing an index.html file that serves as a landing page with navigation links for listing, adding, updating, and deleting staff.

• Displaying Data: Creating a list-staff.html template that uses Thymeleaf attributes (like th:each) to iterate through staff records and display them in a table.

3. Controller Implementation (The "C" in MVC)

• Request Mapping: Creating a StaffController class annotated with @Controller and @RequestMapping("/staffs") to handle specific URL requests.

• Handling GET Requests:

  • Implementing a method to fetch all staff from the repository and pass them to the "list" view.

  • Creating a method to display the registration form for new staff members.

• Handling Data Persistence: Developing an addStaff method that validates input, saves a new staff object to the database via the repository, and redirects the user back to the staff list.

4. Application Testing

• URL Verification: Accessing the application via http://localhost:8080 to view the UI.

• Debugging Request Handling: Identifying and resolving "WhiteLabel Error Pages" (404 errors) by ensuring the Controller is correctly configured to handle view requests.