register api

src/main/java/io/spring/infrastructure/user/MyBatisUserRepository.java

@@ -0,0 +1,33 @@
+package io.spring.infrastructure.user;
+
+import io.spring.core.user.User;
+import io.spring.core.user.UserRepository;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Repository;
+
+import java.util.Optional;
+
+@Repository
+public class MyBatisUserRepository implements UserRepository {
+    private final UserMapper userMapper;
+
+    @Autowired
+    public MyBatisUserRepository(UserMapper userMapper) {
+        this.userMapper = userMapper;
+    }
+
+    @Override
+    public void save(User user) {
+        userMapper.save(user);
+    }
+
+    @Override
+    public Optional<User> findByUsername(String username) {
+        return Optional.ofNullable(userMapper.findByUsername(username));
+    }
+
+    @Override
+    public Optional<User> findByEmail(String email) {
+        return Optional.ofNullable(userMapper.findByEmail(email));
+    }
+}

src/main/java/io/spring/infrastructure/user/UserMapper.java

@@ -0,0 +1,15 @@
+package io.spring.infrastructure.user;
+
+import io.spring.core.user.User;
+import org.apache.ibatis.annotations.Mapper;
+import org.apache.ibatis.annotations.Param;
+import org.springframework.stereotype.Component;
+
+@Component
+@Mapper
+public interface UserMapper {
+    void save(@Param("user") User user);
+
+    User findByUsername(@Param("username") String username);
+    User findByEmail(@Param("email") String email);
+}