add get student by id in API

back-skeleton/src/main/java/com/takima/backskeleton/controllers/StudentController.java

@@ -22,6 +22,11 @@ public class StudentController {
         return studentService.findAll();
     }
 
+    @GetMapping("/{id}")
+    public Student getStudentById(@PathVariable Long id) {
+        return studentService.getById(id);
+    }
+
     @DeleteMapping("/{id}")
     public void deleteStudent(@PathVariable Long id) {
         studentService.deleteById(id);

back-skeleton/src/main/java/com/takima/backskeleton/services/StudentService.java

@@ -24,6 +24,10 @@ public class StudentService {
         return users ;
     }
 
+    public Student getById(Long id) {
+        return studentDao.findById(id).orElseThrow();
+    }
+
     public void deleteById(Long id) {
         studentDao.deleteById(id);
     }