Service implementation

Drafts/dbdemo/pom.xml

@@ -54,6 +54,11 @@
             <groupId>org.flywaydb</groupId>
             <artifactId>flyway-core</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <optional>true</optional>
+        </dependency>
     </dependencies>
 
     <build>

Drafts/dbdemo/src/main/java/de/telran/Application.java

@@ -0,0 +1,11 @@
+package de.telran;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class Application {
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+}

Drafts/dbdemo/src/main/java/de/telran/controller/StudentController.java

@@ -0,0 +1,40 @@
+package de.telran.controller;
+
+import de.telran.model.Student;
+import de.telran.service.StudentService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.PutMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+public class StudentController {
+
+    StudentService service;
+
+    @Autowired
+    public StudentController(StudentService service) {
+        this.service = service;
+    }
+
+    @GetMapping
+    List<Student> getAllStudents() {
+        return service.getAllStudents();
+    }
+
+    @PostMapping("/api/students")
+    Student createStudent(@RequestBody Student student) {
+        return service.createStudent(student);
+    }
+
+    @PutMapping("/api/students")
+    Student assignStudentToCourse(@RequestBody Student student) {
+        service.assignStudentToCourse(student);
+        return service.getStudentById(student.getStudentId());
+    }
+
+}

Drafts/dbdemo/src/main/java/de/telran/model/Student.java

@@ -0,0 +1,20 @@
+package de.telran.model;
+
+import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import lombok.Data;
+import org.springframework.lang.Nullable;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Data
+@Entity
+@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
+public class Student {
+    private @Id @GeneratedValue(strategy = GenerationType.IDENTITY) Long studentId;
+    private String firstName;
+    private String lastName;
+    private @Nullable Long courseId;
+}

Drafts/dbdemo/src/main/java/de/telran/repository/StudentRepository.java

@@ -0,0 +1,16 @@
+package de.telran.repository;
+
+import de.telran.model.Student;
+import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Modifying;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
+import org.springframework.transaction.annotation.Transactional;
+
+public interface StudentRepository extends JpaRepository<Student, Long> {
+
+    @Transactional
+    @Modifying
+    @Query("UPDATE Student s SET s.courseId = :courseId WHERE s.studentId = :studentId")
+    int assignStudentToCourse(@Param("studentId") long studentId, @Param("courseId") long courseId);
+}

Drafts/dbdemo/src/main/java/de/telran/service/StudentService.java

@@ -0,0 +1,31 @@
+package de.telran.service;
+
+import de.telran.model.Student;
+import de.telran.repository.StudentRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.util.List;
+
+@Service
+public class StudentService {
+
+    @Autowired
+    StudentRepository repository;
+
+    public List<Student> getAllStudents() {
+        return repository.findAll();
+    }
+
+    public Student createStudent(Student student) {
+        return repository.save(student);
+    }
+
+    public void assignStudentToCourse(Student student) {
+        repository.assignStudentToCourse(student.getStudentId(), student.getCourseId());
+    }
+
+    public Student getStudentById(Long id) {
+        return repository.getOne(id);
+    }
+}