Added possible crypt password, create repository user implementation, etc...

src/main/java/service/UserService.java

@@ -1,11 +1,18 @@
 package service;
 
 import models.User;
+import repository.UserRepository;
 
 import java.util.Optional;
 
 public class UserService {
 
+    UserRepository userRepository;
+
+    public UserService(UserRepository userRepository) {
+        this.userRepository = userRepository;
+    }
+
     public Optional<User> login(String username, String password) {
         try {
 
@@ -18,13 +25,11 @@ public class UserService {
         }
     }
 
-    public Optional<User> register(String username, String password) {
+    public Optional<User> register(String username, String email, String password) {
         try {
-
-
-            return Optional.empty();
+            return userRepository.saveUser(username, email, password);
         } catch (Exception e) {
-            System.out.println(e.getMessage());
+            e.printStackTrace();
             return Optional.empty();
         }
     }