bug修复

src/main/java/com/codesdream/ase/controller/student/StudentController.java

@@ -7,5 +7,5 @@ import org.springframework.web.bind.annotation.RestController;
 @RequestMapping("student")
 public class StudentController {
 
-    public 
+    //public
 }

src/main/java/com/codesdream/ase/service/CalculationService.java

@@ -31,7 +31,7 @@ public class CalculationService {
      * @return 计算好的学分绩
      */
     public float calculateGPA(int studentId){
-        if(checkStudentExistence(studentId)){
+        if(!checkStudentExistence(studentId)){
             throw new NotFoundException("No such student.");
         }
         List<StudentCourse> studentCourses = studentCourseRepository.findByStudentId(studentId);