feat: User save api development

api/src/main/java/project/dailyge/app/core/user/application/UserWriteService.java

@@ -0,0 +1,5 @@
+package project.dailyge.app.core.user.application;
+
+public interface UserWriteService {
+    Long save(String name);
+}

api/src/main/java/project/dailyge/app/core/user/application/service/UserService.java

@@ -3,13 +3,14 @@
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Service;
 import project.dailyge.app.core.user.application.UserReadService;
+import project.dailyge.app.core.user.application.UserWriteService;
 import project.dailyge.app.core.user.exception.UserNotFoundException;
 import project.dailyge.entity.user.User;
 import project.dailyge.entity.user.UserEntityReadRepository;
 
 @Service
 @RequiredArgsConstructor
-public class UserService implements UserReadService {
+public class UserService implements UserReadService, UserWriteService {
 
     private final UserEntityReadRepository userReadRepository;
 
@@ -18,4 +19,11 @@ public User findById(final Long userId) {
         return userReadRepository.findById(userId)
             .orElseThrow(() -> new UserNotFoundException("사용자를 찾을 수 없습니다."));
     }
+
+    @Override
+    public Long save(final String name) {
+        final User newUser = new User(null, name);
+        userReadRepository.save(newUser);
+        return newUser.getId();
+    }
 }

api/src/main/java/project/dailyge/app/core/user/persistence/UserRepository.java

@@ -7,21 +7,25 @@
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
+import java.util.concurrent.atomic.AtomicLong;
 
 @Repository
 public class UserRepository implements UserEntityReadRepository {
 
+    private final AtomicLong idGenerator = new AtomicLong(0);
     private final Map<Long, User> map = new HashMap<>();
 
-    public UserRepository() {
-        map.put(1L, new User(1L, "User-01"));
-        map.put(2L, new User(1L, "User-02"));
-    }
-
     @Override
     public Optional<User> findById(final Long userId) {
         return Optional.ofNullable(
             map.get(userId)
         );
     }
+
+    @Override
+    public void save(final User user) {
+        final Long newId = idGenerator.incrementAndGet();
+        user.insert(newId);
+        map.put(newId, user);
+    }
 }