UF01-1844

Subject

Create a Spring MVC Thyemeleaf with all CRUD operations for a single object. No persistante needed.

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Model

Student class and attributes. Lombok annotation has been used to create setters, getters and constructors.

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Student.java

@Data
@NoArgsConstructor
@AllArgsConstructor
public class Student {
    private String studentID;
    private String firstName;
    private String lastName;
    private String email;
}

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Utils class

Created a utils class that will help to create unique ID’s for each object and populating our non-persistent DB.

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Utils.java

public class Utils {

    public static String createUUID() {
        UUID uuid = UUID.randomUUID();
        String id = uuid.toString();
        return id;
    }

    public static HashMap<String, Student> populateStudents(int qty, HashMap<String, Student> students ) {

        Faker faker = new Faker();
        Student newStudent;

        for (int i = 0; i < qty; i++) {
            newStudent = new Student();

            String studentID = Utils.createUUID();
            newStudent.setStudentID(studentID);

            String studentFirstName = faker.name().firstName();
            newStudent.setFirstName(studentFirstName);

            String studentLastName = faker.name().lastName();
            newStudent.setLastName(studentLastName);

            newStudent.setEmail("fake@email.com");

            students.put(studentID, newStudent);

        }
        return  students;
    }

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Service

Service class with all the busines logic needed for CRUD operations

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Service.java

@Service
public class StudentService {
    public static HashMap<String, Student> students = new HashMap<>();

    static {
        Utils.populateStudents(5, students);
    }

    public static void populateDB(int qty) {
        Utils.populateStudents(qty,students);
    }

    public  void createStudent(Student student) {

        String  studentID = Utils.createUUID();
        student.setStudentID(studentID);
        students.put(studentID, student);
    }

    public HashMap<String, Student> getAllStudents (){
        return students;
    }

    public Student createStudent(){
        Student student = new Student();
        student.setEmail("");
        return student;
    }

    public Student findStudentByID(String studentID) {
        return students.getOrDefault(studentID, null);
    }

    public void updateStudentByStudentID(Student studentFound) {
        students.put(studentFound.getStudentID(), studentFound);
    }

    public void deleteStudentByStudentID(String studentID) {
        students.remove(studentID);
    }
}

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Controller

Here is the controller and all the end-points needed to perform CRUD operations

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Controller.java

@Controller
@RequestMapping("/student")
public class StudentController {

    @Autowired
    StudentService studentService;

    @RequestMapping("/students")
    public String getAllUsers(Model model){
        // fetch all users, add to model
        model.addAttribute("students", studentService.getAllStudents());
        return "student/students";
    }
    @RequestMapping("/createStudent")
    public String createUser(Student student){
        studentService.createStudent(student);
        return "redirect:students";
    }

    @RequestMapping("/studentForm")
    public String sendForm(){

        return "student/studentForm";
    }

    @RequestMapping("/packedStudent")
    public String packedStudents(@RequestParam("studentID") String studentID, Model model){

        Student studentFound = studentService.findStudentByID(studentID);

        if (studentFound != null){
            model.addAttribute("studentFromController", studentFound);
            model.addAttribute("message", "Student  found");}
        else
            model.addAttribute("message", "Student not found");

        return "student/studentToUpdate";
    }

    @PostMapping("/updateStudent/{studentID}")
    public String updateUser(@PathVariable("studentID") String studentID,
                             Student updatedStudent) {

        Student studentFound = studentService.findStudentByID(studentID);

        if (studentFound != null) {
            studentService.updateStudentByStudentID(updatedStudent);
            return "redirect:/student/students";
        } else return "student/studentNotFound";
    }

    @RequestMapping("/deleteStudent")
    public String deleteStudent(@RequestParam("studentID") String studentID) {

        Student studentFound = studentService.findStudentByID(studentID);

        if (studentFound != null) {
            studentService.deleteStudentByStudentID(studentID);
            return "redirect:/student/students";
        } else return "student/studentNotFound";

    }

    @RequestMapping("/studentDetails")
    public String studentDetails(@RequestParam("studentID") String studentID, Model model) {

        Student studentFound = studentService.findStudentByID(studentID);

        if (studentFound != null) {
            model.addAttribute("student",studentFound );
            return "/student/studentDetails";
        } else return "student/studentNotFound";

    }

    @RequestMapping("/createFakeStudents")
    public String createFakeStudents (@RequestParam("qty") int qty) {
        StudentService.populateDB(qty);
        return "redirect:/student/students";
    }
}

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Tree folder project structure

Here’s the structure of the project. Note that there’s a Index Controller to manage the home page.

Project Structure

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Dependencies

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    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-thymeleaf</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- https://mvnrepository.com/artifact/com.github.javafaker/javafaker -->
        <dependency>
            <groupId>com.github.javafaker</groupId>
            <artifactId>javafaker</artifactId>
            <version>1.0.2</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
                <configuration>
                    <excludes>
                        <exclude>
                            <groupId>org.projectlombok</groupId>
                            <artifactId>lombok</artifactId>
                        </exclude>
                    </excludes>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

Source code Git Hub Repository