add uniqueness to email in Model and findByEmail

src/main/java/com/student/details/controllers/DetailsController.java

 package com.student.details.controllers;
 
+import com.student.details.exceptions.ResourceNotFoundException;
 import com.student.details.models.Student;
 import com.student.details.services.StudentService;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.web.bind.annotation.CrossOrigin;
-import org.springframework.web.bind.annotation.GetMapping;
-import org.springframework.web.bind.annotation.RequestMapping;
-import org.springframework.web.bind.annotation.RestController;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
 
 import java.util.List;
+import java.util.Map;
 
 @CrossOrigin(origins = "*")
 @RestController
@@ -24,4 +24,37 @@ public class DetailsController {
     return studentService.findAllStudents();
   }
 
+  @PostMapping("/students")
+  public Student createStudent(@RequestBody Student student) {
+    return studentService.addStudent(student);
+  }
+
+  @GetMapping("/students/{id}")
+  public ResponseEntity<Student> getStudentById(@PathVariable(value = "id") Long studentId) throws ResourceNotFoundException {
+    Student student = studentService.getStudentById(studentId)
+            .orElseThrow(() -> new ResourceNotFoundException("Student by Id Not Found" + studentId));
+    return ResponseEntity.ok().body(student);
+  }
+
+  @GetMapping("/students/email/{email:.+}")
+  public ResponseEntity<Student> getStudentByEmail(@PathVariable(value = "email") String email) throws ResourceNotFoundException {
+    Student student = studentService.getStudentByEmail(email)
+            .orElseThrow(() -> new ResourceNotFoundException("Student with email" + email + "not found."));
+    return ResponseEntity.ok().body(student);
+  }
+
+  @PutMapping("/students/{id}")
+  public Student updateStudent(@PathVariable(value = "id") Long studentId, @RequestBody Student student) throws ResourceNotFoundException {
+    Student studentToUpdate = studentService.getStudentById(studentId)
+            .orElseThrow(() -> new ResourceNotFoundException("Student by Id Not Found" + studentId));
+    return studentService.updateStudent(studentId, student);
+  }
+
+  @DeleteMapping("/students/{id}")
+  public Map<String, Boolean> deleteEmployee(@PathVariable(value = "id") Long studentId) throws ResourceNotFoundException {
+    Student student = studentService.getStudentById(studentId)
+            .orElseThrow(() -> new ResourceNotFoundException("Student by Id Not Found" + studentId));
+    return studentService.deleteStudent(studentId);
+
+  }
 }

src/main/java/com/student/details/models/Student.java

@@ -11,7 +11,9 @@ public class Student {
   @GeneratedValue(strategy = GenerationType.IDENTITY)
   private Long id;
 
+  @Column(unique = true)
   private String email;
+
   private String firstName;
   private String lastName;
   private LocalDate dateOfBirth;

src/main/java/com/student/details/repositories/StudentRepository.java

@@ -2,10 +2,16 @@ package com.student.details.repositories;
 
 import com.student.details.models.Student;
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
 import org.springframework.stereotype.Repository;
 
+import java.util.Optional;
+
 @Repository
 public interface StudentRepository extends JpaRepository<Student, Long> {
 
+  @Query("from Student s where s.email = ?1")
+  Optional<Student> findStudentByEmail(String email);
+
 }
 

src/main/java/com/student/details/services/StudentService.java

@@ -30,6 +30,10 @@ public class StudentService {
         return studentRepository.findById(studentId);
     }
 
+    public Optional<Student> getStudentByEmail(String email) {
+        return studentRepository.findStudentByEmail(email);
+    }
+
     public Student updateStudent(Long studentId, Student studentDetails) throws ResourceNotFoundException {
         Student student = studentRepository.findById(studentId)
                 .orElseThrow(() -> new ResourceNotFoundException("Student id: " + studentId + " not found"));