Tutusfunny

Introduction to Spring Boot and RESTful APIs

Spring Boot is a powerful framework for building Java applications, particularly RESTful APIs. In this tutorial, we will guide you through a complete Spring Boot RESTful API CRUD project,This course is designed for beginners, so no prior Spring Boot experience is necessary.

Crud function how to perform the RESTful Web Service let discuss with following annotations.

@PostMapping:  annotation which used to create new record.
@GetMapping:   annotation which used to reads a record.
@RequestMapping: annotation which used to search the record.
@PutMapping:   annotation which used to update the existing record.
@DeleteMapping:  annotation which used to delete the record.

Lets Started Project

First Step go to Spring Initializer to configure the project using the following dependencies.

1.  Spring Data JPA
2.  Spring Web
3.  Lombok
4.  MySQL Driver

@Entity
@Table(name ="teacher")
public class Teacher {

    @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    @Column(name="teacher_id",length = 11)
    private int teacherid;

    @Column(name="teacher_name",length = 45)
    private String teachername;

    @Column(name="phone",length = 11)
    private String phone;

    //constructor

    public Teacher(int teacherid, String teachername, String phone) {
        this.teacherid = teacherid;
        this.teachername = teachername;
        this.phone = phone;
    }

    public Teacher(String teachername, String phone) {
        this.teachername = teachername;
        this.phone = phone;
    }

    public Teacher() {
    }

    public int getTeacherid() {
        return teacherid;
    }

    public void setTeacherid(int teacherid) {
        this.teacherid = teacherid;
    }

    public String getTeachername() {
        return teachername;
    }

    public void setTeachername(String teachername) {
        this.teachername = teachername;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    @Override
    public String toString() {
        return "Teacher{" +
                "teacherid=" + teacherid +
                ", teachername='" + teachername + '\'' +
                ", phone='" + phone + '\'' +
                '}';
    }

Create the Package DTO

Inside the Package create the class TeacherDTO and TeacherSaveDTO and TeacherUpdateDTO

TeacherDTO

@AllArgsConstructor
@NoArgsConstructor
@Data
public class TeacherDTO {

    private int teacherid;
    private String teachername;
    private String phone;

}

TeacherSaveDTO

@AllArgsConstructor
@NoArgsConstructor
@Data
public class TeacherSaveDTO 
{
    private String teachername;
    private String phone;
}

TeacherUpdateDTO

@AllArgsConstructor
@NoArgsConstructor
@Data
public class TeacherUpdateDTO {
    private int teacherid;
    private String teachername;
    private String phone;

}

Create the Package Controller

nside the Package create the class TeacherController

@RestController
@CrossOrigin
@RequestMapping("api/v1/teacher")
public class TeacherController {

      @Autowired
      private TeacherService teacherService;

      @PostMapping("/save")
      public String saveTeacher(@RequestBody TeacherSaveDTO teacherSaveDTO)
      {
          String teachername = teacherService.addTeacher(teacherSaveDTO);
          return teachername;
      }

      @GetMapping("/getAllTeachers")
      public List<TeacherDTO> getAllTeachers()
      {
          List<TeacherDTO> allTeachers = teacherService.getAllTeachers();
          return allTeachers;
      }

      @PutMapping("/update")
      public String updateTeacher(@RequestBody TeacherUpdateDTO teacherUpdateDTO)
      {
          String teachername = teacherService.updateTeacher(teacherUpdateDTO);
          return "updateee";
      }

      @DeleteMapping("/delete/{id}")
    public String deleteTeacher(@PathVariable(value = "id")int id)
      {
          boolean deleteTeacher = teacherService.deleteTeacher(id);
          return "deleteeeedd";
      }

}

Teacher Service

Inside the Package create the interface TeacherService.java and TeacherServiceIMPL.java.

TeacherService

public interface TeacherService {
    String addTeacher(TeacherSaveDTO teacherSaveDTO);

    List<TeacherDTO> getAllTeachers();

    String updateTeacher(TeacherUpdateDTO teacherUpdateDTO);

    boolean deleteTeacher(int id);
}

TeacherServiceIMPL

@Service
public class TeacherServiceIMPL implements TeacherService {

    @Autowired
    private TeacherRepo teacherRepo;

    @Override
    public String addTeacher(TeacherSaveDTO teacherSaveDTO) {

        Teacher teacher = new Teacher(
                teacherSaveDTO.getTeachername(),
                teacherSaveDTO.getPhone()

        );
        teacherRepo.save(teacher);
        return teacher.getTeachername();
    }

    @Override
    public List<TeacherDTO> getAllTeachers() {

        List<Teacher> getTeacher = teacherRepo.findAll();
        List<TeacherDTO> teacherDTOList = new ArrayList<>();

        for(Teacher teacher:getTeacher)
        {
            TeacherDTO teacherDTO = new TeacherDTO(
                    teacher.getTeacherid(),
                    teacher.getTeachername(),
                    teacher.getPhone()
            );

            teacherDTOList.add(teacherDTO);
        }

        return teacherDTOList;
    }

    @Override
    public String updateTeacher(TeacherUpdateDTO teacherUpdateDTO) {

        if(teacherRepo.existsById(teacherUpdateDTO.getTeacherid()))
        {
            Teacher teacher = teacherRepo.getById(teacherUpdateDTO.getTeacherid());
            teacher.setTeachername(teacherUpdateDTO.getTeachername());
            teacher.setPhone(teacherUpdateDTO.getPhone());

            teacherRepo.save(teacher);

            return  teacher.getTeachername();
        }
        else
        {
            System.out.println("Teacher ID not Found");
        }
        return null;
    }

    @Override
    public boolean deleteTeacher(int id) {

        if(teacherRepo.existsById(id))
        {
            teacherRepo.deleteById(id);
        }
        else
        {
            System.out.println("Teacher ID not Found");
        }
        return false;
    }

TeacherRepo

public interface TeacherRepo extends JpaRepository<Teacher,Integer> {
}