JDBC Step4 띠용 (#1235)

* feat: UserService 인터페이스 분리 및 트랜잭션 관리 개선

- UserService를 인터페이스로 분리하여 책임 분리
- AppUserService와 TxUserService 구현체 추가
- TxUserService에 TransactionManager 적용으로 트랜잭션 처리 캡슐화
- 코드 가독성과 유지보수성 향상

* refactor: 트랜잭션 관리 개선 및 중복 코드 제거

- TransactionSynchronizationManager에 자원 바인딩 및 해제 로직 추가
- DataSourceUtils의 releaseConnection 개선으로 안전한 리소스 해제
- JdbcTemplate 및 TransactionManager에서 중복 코드 제거 및 자원 관리 개선
- UserDao 및 UserHistoryDao의 Connection 기반 메서드 제거로 사용되지 않는 메서드 정리
- AppUserService 및 TxUserService로 트랜잭션 분리 및 예외 메시지 명확화

* refactor: releaseConnection 메서드의 트랜잭션 바인딩 검증 로직 개선

- TransactionSynchronizationManager의 isBound 메서드 활용으로 코드 간결화
- 불필요한 null 체크 로직 제거 및 리소스 해제 처리 안정

* refactor: releaseConnection 호출 순서 수정

- 트랜잭션 리소스 해제 순서 명확화 및 안정성 강화

* refactor: 트랜잭션 자원 해제 로직 개선 및 불필요한 import 제거

- TransactionSynchronizationManager에 releaseThreadLocalMap 메서드 추가로 자원 해제 처리 간결화
- 트랜잭션 리소스 해제 시 ThreadLocal에서 빈 맵 제거로 메모리 낭비 방지
- AppUserService 및 UserService에서 사용되지 않는 Connection import 제거로 코드 정리 및 가독성 향상

* refactor: 트랜잭션 롤백 및 autoCommit 복원 로직 개선

- 트랜잭션 롤백 시 발생한 SQLException을 suppressed로 추가하여 디버깅 정보 강화
- 트랜잭션 종료 후 원래 autoCommit 상태로 복원하도록 로직 수정
- DataAccessException 메시지 구체화 및 명확성 향상

Author: jye326

app/src/main/java/com/techcourse/dao/UserDao.java

@@ -30,11 +30,6 @@ public void update(final User user) {
         jdbcTemplate.update(sql, user.getAccount(), user.getPassword(), user.getEmail(), user.getId());
     }
 
-    public void update(Connection connection, final User user) {
-        final var sql = "update users set account = ?, password = ?, email = ? where id = ?";
-        jdbcTemplate.update(connection, sql, user.getAccount(), user.getPassword(), user.getEmail(), user.getId());
-    }
-
     public List<User> findAll() {
         final var sql = "select id, account, password, email from users";
         return jdbcTemplate.query(sql, new UserRowMapper());
@@ -49,8 +44,4 @@ public User findByAccount(final String account) {
         final var sql = "select id, account, password, email from users where account = ?";
         return jdbcTemplate.executeQueryForObject(sql, new UserRowMapper(), account);
     }
-
-    public DataSource getDataSource() {
-        return jdbcTemplate.getDataSource();
-    }
 }

app/src/main/java/com/techcourse/dao/UserHistoryDao.java

@@ -27,16 +27,4 @@ public void log(final UserHistory userHistory) {
                 userHistory.getCreateBy()
         );
     }
-
-    public void log(final Connection conn, final UserHistory userHistory) {
-        jdbcTemplate.update(conn,
-                INSERT_USER_HISTORY_SQL,
-                userHistory.getUserId(),
-                userHistory.getAccount(),
-                userHistory.getPassword(),
-                userHistory.getEmail(),
-                userHistory.getCreatedAt(),
-                userHistory.getCreateBy()
-        );
-    }
 }

app/src/main/java/com/techcourse/service/AppUserService.java

@@ -0,0 +1,32 @@
+package com.techcourse.service;
+
+import com.techcourse.dao.UserDao;
+import com.techcourse.dao.UserHistoryDao;
+import com.techcourse.domain.User;
+import com.techcourse.domain.UserHistory;
+
+public class AppUserService implements UserService{
+
+    private final UserDao userDao;
+    private final UserHistoryDao userHistoryDao;
+
+    public AppUserService(final UserDao userDao, final UserHistoryDao userHistoryDao) {
+        this.userDao = userDao;
+        this.userHistoryDao = userHistoryDao;
+    }
+
+    public User findById(final long id) {
+        return userDao.findById(id);
+    }
+
+    public void save(User user) {
+        userDao.insert(user);
+    }
+
+    public void changePassword(final long id, final String newPassword, final String createdBy) {
+        final var user = findById(id);
+        user.changePassword(newPassword);
+        userDao.update(user);
+        userHistoryDao.log(new UserHistory(user, createdBy));
+    }
+}

app/src/main/java/com/techcourse/service/TxUserService.java

@@ -0,0 +1,33 @@
+package com.techcourse.service;
+
+import com.interface21.transaction.TransactionManager;
+import com.techcourse.config.DataSourceConfig;
+import com.techcourse.domain.User;
+
+public class TxUserService implements UserService {
+
+    private final TransactionManager transactionManager;
+    private final UserService userService;
+
+    public TxUserService(UserService userService) {
+        this.userService = userService;
+        transactionManager = new TransactionManager(DataSourceConfig.getInstance());
+    }
+
+    @Override
+    public User findById(long id) {
+        return userService.findById(id);
+    }
+
+    @Override
+    public void save(User user) {
+        userService.save(user);
+    }
+
+    @Override
+    public void changePassword(long id, String newPassword, String createdBy) {
+        transactionManager.executeTransaction(connection -> {
+            userService.changePassword(id, newPassword, createdBy);
+        });
+    }
+}

app/src/main/java/com/techcourse/service/UserService.java

@@ -1,47 +1,10 @@
 package com.techcourse.service;
 
-import com.interface21.dao.DataAccessException;
-import com.interface21.jdbc.JdbcExecutionException;
-import com.interface21.transaction.TransactionManager;
-import com.techcourse.config.DataSourceConfig;
-import com.techcourse.dao.UserDao;
-import com.techcourse.dao.UserHistoryDao;
 import com.techcourse.domain.User;
-import com.techcourse.domain.UserHistory;
-import java.sql.Connection;
-import java.sql.SQLException;
-import javax.sql.DataSource;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 
-public class UserService {
+public interface UserService {
 
-    private static final Logger log = LoggerFactory.getLogger(UserService.class);
-    private final UserDao userDao;
-    private final UserHistoryDao userHistoryDao;
-    private final TransactionManager transactionManager;
-
-    public UserService(final UserDao userDao, final UserHistoryDao userHistoryDao) {
-        this.userDao = userDao;
-        this.userHistoryDao = userHistoryDao;
-        DataSource dataSource = DataSourceConfig.getInstance();
-        transactionManager = new TransactionManager(dataSource);
-    }
-
-    public User findById(final long id) {
-        return userDao.findById(id);
-    }
-
-    public void insert(final User user) {
-        userDao.insert(user);
-    }
-
-    public void changePassword(final long id, final String newPassword, final String createBy) {
-        final var user = findById(id);
-        user.changePassword(newPassword);
-        transactionManager.executeTransaction(connection -> {
-            userDao.update(connection, user);
-            userHistoryDao.log(connection, new UserHistory(user, createBy));
-        });
-    }
+    User findById(final long id);
+    void save(final User user);
+    void changePassword(final long id, final String newPassword, final String createdBy);
 }

app/src/test/java/com/techcourse/service/MockUserHistoryDao.java

@@ -16,9 +16,4 @@ public MockUserHistoryDao(final JdbcTemplate jdbcTemplate) {
     public void log(final UserHistory userHistory) {
         throw new DataAccessException();
     }
-
-    @Override
-    public void log(final Connection connection, final UserHistory userHistory) {
-        throw new DataAccessException();
-    }
 }

app/src/test/java/com/techcourse/service/UserServiceTest.java

@@ -8,7 +8,6 @@
 import com.interface21.dao.DataAccessException;
 import com.interface21.jdbc.core.JdbcTemplate;
 import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -32,7 +31,7 @@ void setUp() {
     @Test
     void testChangePassword() {
         final var userHistoryDao = new UserHistoryDao(jdbcTemplate);
-        final var userService = new UserService(userDao, userHistoryDao);
+        final var userService = new AppUserService(userDao, userHistoryDao);
 
         final var newPassword = "qqqqq";
         final var createBy = "gugu";
@@ -47,13 +46,16 @@ void testChangePassword() {
     void testTransactionRollback() {
         // 트랜잭션 롤백 테스트를 위해 mock으로 교체
         final var userHistoryDao = new MockUserHistoryDao(jdbcTemplate);
-        final var userService = new UserService(userDao, userHistoryDao);
+        // 애플리케이션 서비스
+        final var appUserService = new AppUserService(userDao, userHistoryDao);
+        // 트랜잭션 서비스 추상화
+        final var userService = new TxUserService(appUserService);
 
         final var newPassword = "newPassword";
-        final var createBy = "gugu";
+        final var createdBy = "gugu";
         // 트랜잭션이 정상 동작하는지 확인하기 위해 의도적으로 MockUserHistoryDao에서 예외를 발생시킨다.
         assertThrows(DataAccessException.class,
-                () -> userService.changePassword(1L, newPassword, createBy));
+                () -> userService.changePassword(1L, newPassword, createdBy));
 
         final var actual = userService.findById(1L);
 

jdbc/src/main/java/com/interface21/jdbc/core/JdbcTemplate.java

@@ -1,6 +1,7 @@
 package com.interface21.jdbc.core;
 
 import com.interface21.jdbc.JdbcExecutionException;
+import com.interface21.jdbc.datasource.DataSourceUtils;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
@@ -27,14 +28,16 @@ public int update(final String sql, final Object... parameters) {
     }
 
     private <T> T execute(String sql, PreparedStatementExecutor<T> executor, Object[] parameters) {
-        try (Connection conn = dataSource.getConnection();
-             PreparedStatement pstmt = conn.prepareStatement(sql)) {
+        Connection conn = DataSourceUtils.getConnection(dataSource);
+        try (PreparedStatement pstmt = conn.prepareStatement(sql);) {
             setStatementParameters(pstmt, parameters);
             log.debug("query : {}, params : {}", sql, Arrays.toString(parameters));
             return executor.execute(pstmt);
         } catch (SQLException e) {
             log.error("executeUpdate failed. sql={}, params={}", sql, Arrays.toString(parameters), e);
             throw new JdbcExecutionException("쿼리 실행 실패 : " + e.getMessage());
+        } finally {
+            DataSourceUtils.releaseConnection(conn, dataSource);
         }
     }
 

jdbc/src/main/java/com/interface21/jdbc/datasource/DataSourceUtils.java

@@ -20,14 +20,16 @@ public static Connection getConnection(DataSource dataSource) throws CannotGetJd
 
         try {
             connection = dataSource.getConnection();
-            TransactionSynchronizationManager.bindResource(dataSource, connection);
             return connection;
         } catch (SQLException ex) {
             throw new CannotGetJdbcConnectionException("Failed to obtain JDBC Connection", ex);
         }
     }
 
     public static void releaseConnection(Connection connection, DataSource dataSource) {
+        if(TransactionSynchronizationManager.isBound(dataSource)){
+            return;
+        }
         try {
             connection.close();
         } catch (SQLException ex) {

jdbc/src/main/java/com/interface21/transaction/TransactionManager.java

@@ -1,6 +1,8 @@
 package com.interface21.transaction;
 
 import com.interface21.dao.DataAccessException;
+import com.interface21.jdbc.datasource.DataSourceUtils;
+import com.interface21.transaction.support.TransactionSynchronizationManager;
 import java.sql.Connection;
 import java.sql.SQLException;
 import javax.sql.DataSource;
@@ -14,19 +16,29 @@ public TransactionManager(DataSource dataSource) {
     }
 
     public void executeTransaction(final TransactionalAction action) {
-        try (Connection connection = dataSource.getConnection()) {
-            // transaction start
+        Connection connection = DataSourceUtils.getConnection(dataSource);
+        boolean originAutoCommit = false;
+        try {
+            originAutoCommit = connection.getAutoCommit();
             connection.setAutoCommit(false);
+            TransactionSynchronizationManager.bindResource(dataSource, connection);
+            action.execute(connection);
+            connection.commit();
+        } catch (Exception e) {
             try {
-                action.execute(connection);
-                connection.commit();
-            } catch (Exception e) {
                 connection.rollback();
-                throw new DataAccessException("트랜잭션 오류발생으로 롤백", e);
+            } catch (SQLException ex) {
+                e.addSuppressed(ex);
             }
-            connection.setAutoCommit(true);
-        } catch (SQLException e) {
-            throw new RuntimeException("커넥션 오류 발생", e);
+            throw new DataAccessException("트랜잭션 수행 중 오류 발생으로 롤백 시도", e);
+        } finally {
+            try {
+                connection.setAutoCommit(originAutoCommit);
+            } catch (SQLException e) {
+                throw new RuntimeException(e);
+            }
+            TransactionSynchronizationManager.unbindResource(dataSource);
+            DataSourceUtils.releaseConnection(connection, dataSource);
         }
     }
 }