[JDBC 라이브러리 구현하기 - 3,4단계] 애쉬(정설희) 미션 제출합니다. (#589)

* feat: Transaction 적용하기

* refactor: TxSynchronizationManager 활용

* refactor: 트랜잭션 서비스 추상화

* refactor: transaction 일괄 적용

* refactor: 트랜잭션 종료 후 setAutoCommit(true) 설정

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

@@ -3,14 +3,11 @@
 import com.techcourse.domain.User;
 import java.util.List;
 import javax.sql.DataSource;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.core.RowMapper;
 
 public class UserDao {
 
-    private static final Logger log = LoggerFactory.getLogger(UserDao.class);
     private static final RowMapper<User> userRowMapper = rs ->
         new User(
             rs.getLong("id"),

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

@@ -1,63 +1,20 @@
 package com.techcourse.dao;
 
 import com.techcourse.domain.UserHistory;
-import java.sql.Connection;
-import java.sql.PreparedStatement;
-import java.sql.SQLException;
-import javax.sql.DataSource;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
 import org.springframework.jdbc.core.JdbcTemplate;
 
 public class UserHistoryDao {
 
-    private static final Logger log = LoggerFactory.getLogger(UserHistoryDao.class);
+    private final JdbcTemplate jdbcTemplate;
 
-    private final DataSource dataSource;
-
-    public UserHistoryDao(final DataSource dataSource) {
-        this.dataSource = dataSource;
-    }
-
-    public UserHistoryDao(final JdbcTemplate jdbcTemplate) {
-        this.dataSource = null;
+    public UserHistoryDao(JdbcTemplate jdbcTemplate) {
+        this.jdbcTemplate = jdbcTemplate;
     }
 
     public void log(final UserHistory userHistory) {
         final var sql = "insert into user_history (user_id, account, password, email, created_at, created_by) values (?, ?, ?, ?, ?, ?)";
 
-        Connection conn = null;
-        PreparedStatement pstmt = null;
-        try {
-            conn = dataSource.getConnection();
-            pstmt = conn.prepareStatement(sql);
-
-            log.debug("query : {}", sql);
-
-            pstmt.setLong(1, userHistory.getUserId());
-            pstmt.setString(2, userHistory.getAccount());
-            pstmt.setString(3, userHistory.getPassword());
-            pstmt.setString(4, userHistory.getEmail());
-            pstmt.setObject(5, userHistory.getCreatedAt());
-            pstmt.setString(6, userHistory.getCreateBy());
-            pstmt.executeUpdate();
-        } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new RuntimeException(e);
-        } finally {
-            try {
-                if (pstmt != null) {
-                    pstmt.close();
-                }
-            } catch (SQLException ignored) {
-            }
-
-            try {
-                if (conn != null) {
-                    conn.close();
-                }
-            } catch (SQLException ignored) {
-            }
-        }
+        jdbcTemplate.update(sql, userHistory.getUserId(), userHistory.getAccount(), userHistory.getPassword(),
+            userHistory.getEmail(), userHistory.getCreatedAt(), userHistory.getCreateBy());
     }
 }

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

@@ -0,0 +1,35 @@
+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(UserDao userDao, UserHistoryDao userHistoryDao) {
+        this.userDao = userDao;
+        this.userHistoryDao = userHistoryDao;
+    }
+
+    @Override
+    public User findById(final long id) {
+        return userDao.findById(id);
+    }
+
+    @Override
+    public void insert(User user) {
+        userDao.insert(user);
+    }
+
+    @Override
+    public void changePassword(final long id, final String newPassword, final String createBy) {
+        final var user = findById(id);
+        user.changePassword(newPassword);
+        userDao.update(user);
+        userHistoryDao.log(new UserHistory(user, createBy));
+    }
+}

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

@@ -0,0 +1,30 @@
+package com.techcourse.service;
+
+import com.techcourse.domain.User;
+import org.springframework.transaction.TransactionManager;
+
+public class TxUserService implements UserService {
+
+    private final UserService userService;
+    private final TransactionManager transactionManager;
+
+    public TxUserService(UserService userService, TransactionManager transactionManager) {
+        this.userService = userService;
+        this.transactionManager = transactionManager;
+    }
+
+    @Override
+    public User findById(long id) {
+        return transactionManager.doTransaction(() -> userService.findById(id));
+    }
+
+    @Override
+    public void insert(User user) {
+        transactionManager.doTransaction(() -> userService.insert(user));
+    }
+
+    @Override
+    public void changePassword(final long id, final String newPassword, final String createBy) {
+        transactionManager.doTransaction(() -> userService.changePassword(id, newPassword, createBy));
+    }
+}

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

@@ -1,32 +1,12 @@
 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 UserService {
+public interface UserService {
 
-    private final UserDao userDao;
-    private final UserHistoryDao userHistoryDao;
+    User findById(final long id);
 
-    public UserService(final UserDao userDao, final UserHistoryDao userHistoryDao) {
-        this.userDao = userDao;
-        this.userHistoryDao = userHistoryDao;
-    }
+    void insert(final User user);
 
-    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);
-        userDao.update(user);
-        userHistoryDao.log(new UserHistory(user, createBy));
-    }
+    void changePassword(final long id, final String newPassword, final String createBy);
 }

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

@@ -12,7 +12,7 @@ public MockUserHistoryDao(final JdbcTemplate jdbcTemplate) {
     }
 
     @Override
-    public void log(final UserHistory userHistory) {
+    public void log(UserHistory userHistory) {
         throw new DataAccessException();
     }
 }

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

@@ -1,28 +1,30 @@
 package com.techcourse.service;
 
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
 import com.techcourse.config.DataSourceConfig;
 import com.techcourse.dao.UserDao;
 import com.techcourse.dao.UserHistoryDao;
 import com.techcourse.domain.User;
 import com.techcourse.support.jdbc.init.DatabasePopulatorUtils;
-import org.springframework.dao.DataAccessException;
-import org.springframework.jdbc.core.JdbcTemplate;
+import java.sql.SQLException;
 import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
+import org.springframework.dao.DataAccessException;
+import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.transaction.TransactionManager;
 
-import static org.assertj.core.api.Assertions.assertThat;
-import static org.junit.jupiter.api.Assertions.assertThrows;
-
-@Disabled
 class UserServiceTest {
 
     private JdbcTemplate jdbcTemplate;
+    private TransactionManager transactionManager;
     private UserDao userDao;
 
     @BeforeEach
     void setUp() {
         this.jdbcTemplate = new JdbcTemplate(DataSourceConfig.getInstance());
+        this.transactionManager = new TransactionManager(DataSourceConfig.getInstance());
         this.userDao = new UserDao(jdbcTemplate);
 
         DatabasePopulatorUtils.execute(DataSourceConfig.getInstance());
@@ -31,9 +33,9 @@ void setUp() {
     }
 
     @Test
-    void testChangePassword() {
+    void testChangePassword() throws SQLException {
         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";
@@ -48,13 +50,16 @@ 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, transactionManager);
 
         final var newPassword = "newPassword";
         final var createBy = "gugu";
         // 트랜잭션이 정상 동작하는지 확인하기 위해 의도적으로 MockUserHistoryDao에서 예외를 발생시킨다.
         assertThrows(DataAccessException.class,
-                () -> userService.changePassword(1L, newPassword, createBy));
+            () -> userService.changePassword(1L, newPassword, createBy));
 
         final var actual = userService.findById(1L);
 

jdbc/src/main/java/org/springframework/jdbc/core/QueryTemplate.java

@@ -6,6 +6,7 @@
 import javax.sql.DataSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.jdbc.datasource.DataSourceUtils;
 
 public class QueryTemplate {
 
@@ -18,14 +19,22 @@ public QueryTemplate(DataSource dataSource) {
     }
 
     public <T> T service(final String sql, final QueryCallback<T> callback, final Object... args) {
-        try (
-            final Connection conn = dataSource.getConnection();
-            final PreparedStatement prepareStatement = setUpPreparedStatement(conn, sql, args);
-        ) {
-            return callback.execute(prepareStatement);
+        PreparedStatement preparedStatement = null;
+        try {
+            final Connection conn = DataSourceUtils.getConnection(dataSource);
+            preparedStatement = setUpPreparedStatement(conn, sql, args);
+            return callback.execute(preparedStatement);
         } catch (SQLException e) {
             log.error(e.getMessage(), e);
             throw new RuntimeException(e);
+        } finally {
+            if (preparedStatement != null) {
+                try {
+                    preparedStatement.close();
+                } catch (SQLException e) {
+                    throw new RuntimeException(e);
+                }
+            }
         }
     }
 

jdbc/src/main/java/org/springframework/jdbc/datasource/DataSourceUtils.java

@@ -1,16 +1,15 @@
 package org.springframework.jdbc.datasource;
 
-import org.springframework.jdbc.CannotGetJdbcConnectionException;
-import org.springframework.transaction.support.TransactionSynchronizationManager;
-
-import javax.sql.DataSource;
 import java.sql.Connection;
 import java.sql.SQLException;
+import javax.sql.DataSource;
+import org.springframework.jdbc.CannotGetJdbcConnectionException;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
 
-// 4단계 미션에서 사용할 것
 public abstract class DataSourceUtils {
 
-    private DataSourceUtils() {}
+    private DataSourceUtils() {
+    }
 
     public static Connection getConnection(DataSource dataSource) throws CannotGetJdbcConnectionException {
         Connection connection = TransactionSynchronizationManager.getResource(dataSource);

jdbc/src/main/java/org/springframework/transaction/TransactionManager.java

@@ -0,0 +1,55 @@
+package org.springframework.transaction;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+import java.util.function.Supplier;
+import javax.sql.DataSource;
+import org.springframework.dao.DataAccessException;
+import org.springframework.jdbc.datasource.DataSourceUtils;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
+
+public class TransactionManager {
+
+    private final DataSource dataSource;
+
+    public TransactionManager(DataSource dataSource) {
+        this.dataSource = dataSource;
+    }
+
+    public <T> T doTransaction(Supplier<T> transactionExecutor) {
+        return executeTransaction(transactionExecutor);
+    }
+
+    public void doTransaction(Runnable transactionExecutor) {
+        executeTransaction(() -> {
+            transactionExecutor.run();
+            return null;
+        });
+    }
+
+    private <T> T executeTransaction(Supplier<T> transactionExecutor) {
+        T result = null;
+        try (final var conn = DataSourceUtils.getConnection(dataSource)) {
+            TransactionSynchronizationManager.bindResource(dataSource, conn);
+            conn.setAutoCommit(false);
+            result = transactionExecutor.get();
+            conn.commit();
+            conn.setAutoCommit(true);
+        } catch (final SQLException e) {
+            rollBack(e, TransactionSynchronizationManager.getResource(dataSource));
+        } finally {
+            TransactionSynchronizationManager.unbindResource(dataSource);
+        }
+        return result;
+    }
+
+    private void rollBack(final SQLException e, final Connection conn) {
+        try {
+            conn.rollback();
+            conn.setAutoCommit(true);
+            throw new DataAccessException(e);
+        } catch (final SQLException exception) {
+            throw new DataAccessException(exception);
+        }
+    }
+}