[4단계 - Transaction synchronization 적용하기] 하루(구은선) 미션 제출합니다.

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

@@ -3,7 +3,6 @@
 import com.interface21.jdbc.core.JdbcTemplate;
 import com.interface21.jdbc.core.RowMapper;
 import com.techcourse.domain.User;
-import java.sql.Connection;
 import java.util.List;
 import java.util.Optional;
 import javax.sql.DataSource;
@@ -41,11 +40,6 @@ 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, ROW_MAPPER);
@@ -56,11 +50,6 @@ public Optional<User> findById(final Long id) {
         return jdbcTemplate.queryForObject(sql, ROW_MAPPER, id);
     }
 
-    public Optional<User> findById(Connection connection, final Long id) {
-        final var sql = "select id, account, password, email from users where id = ?";
-        return jdbcTemplate.queryForObject(connection, sql, ROW_MAPPER, id);
-    }
-
     public Optional<User> findByAccount(final String account) {
         final var sql = "select id, account, password, email from users where account = ?";
         return jdbcTemplate.queryForObject(sql, ROW_MAPPER, account);

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

@@ -2,7 +2,6 @@
 
 import com.interface21.jdbc.core.JdbcTemplate;
 import com.techcourse.domain.UserHistory;
-import java.sql.Connection;
 import javax.sql.DataSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -21,10 +20,9 @@ public UserHistoryDao(final JdbcTemplate jdbcTemplate) {
         this.jdbcTemplate = jdbcTemplate;
     }
 
-    public void log(Connection connection, final UserHistory userHistory) {
+    public void log(final UserHistory userHistory) {
         final var sql = "insert into user_history (user_id, account, password, email, created_at, created_by) values (?, ?, ?, ?, ?, ?)";
         jdbcTemplate.update(
-                connection,
                 sql,
                 userHistory.getUserId(),
                 userHistory.getAccount(),

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

@@ -0,0 +1,37 @@
+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 UserServiceInterface {
+
+    private final UserDao userDao;
+    private final UserHistoryDao userHistoryDao;
+
+    public AppUserService(UserDao userDao, UserHistoryDao userHistoryDao) {
+        this.userDao = userDao;
+        this.userHistoryDao = userHistoryDao;
+    }
+
+    @Override
+    public User findById(long id) {
+        return userDao.findById(id)
+                .orElseThrow(() -> new IllegalArgumentException("사용자 정보가 존재하지 않습니다."));
+    }
+
+    @Override
+    public void save(User user) {
+        userDao.insert(user);
+    }
+
+    @Override
+    public void changePassword(long id, String newPassword, String createdBy) {
+        final var user = userDao.findById(id)
+                .orElseThrow(() -> new IllegalArgumentException("사용자 정보가 존재하지 않습니다."));
+        user.changePassword(newPassword);
+        userDao.update(user);
+        userHistoryDao.log(new UserHistory(user, createdBy));
+    }
+}

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

@@ -0,0 +1,86 @@
+package com.techcourse.service;
+
+import com.interface21.dao.DataAccessException;
+import com.interface21.jdbc.core.TransactionCallback;
+import com.interface21.jdbc.datasource.DataSourceUtils;
+import com.techcourse.config.DataSourceConfig;
+import com.techcourse.domain.User;
+import java.sql.Connection;
+import java.sql.SQLException;
+import javax.sql.DataSource;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class TxUserService implements UserServiceInterface {
+
+    private static final Logger log = LoggerFactory.getLogger(TxUserService.class);
+    private final UserServiceInterface userServiceInterface;
+
+    public TxUserService(UserServiceInterface userServiceInterface) {
+        this.userServiceInterface = userServiceInterface;
+    }
+
+    // override 대상인 메서드는 userService의 메서드를 그대로 위임(delegate)한다.
+    @Override
+    public void changePassword(final long id, final String newPassword, final String createdBy) {
+        executeTransaction(() -> userServiceInterface.changePassword(id, newPassword, createdBy));
+    }
+
+    @Override
+    public void save(User user) {
+        executeTransaction(() -> userServiceInterface.save(user));
+    }
+
+    @Override
+    public User findById(long id) {
+        return executeTransaction(() -> userServiceInterface.findById(id));
+    }
+
+    private void executeTransaction(Runnable runnable) {
+        executeTransaction(() -> {
+            runnable.run();
+            return null;
+        });
+    }
+
+    private <T> T executeTransaction(TransactionCallback<T> transactionCallback) {
+        DataSource dataSource = DataSourceConfig.getInstance();
+        Connection connection = null;
+        try {
+            connection = DataSourceUtils.getConnection(dataSource);
+            connection.setAutoCommit(false);
+            T result = transactionCallback.doInTransaction();
+            connection.commit();
+            return result;
+        } catch (SQLException e) {
+            if (connection != null) {
+                try {
+                    connection.rollback();
+                } catch (SQLException ex) {
+                    log.error("Rollback failed", ex);
+                    throw new DataAccessException("Rollback failed");
+                }
+            }
+            throw new DataAccessException(e);
+        } catch (RuntimeException e) {
+            if (connection != null) {
+                try {
+                    connection.rollback();
+                } catch (SQLException ex) {
+                    log.error("Rollback failed", ex);
+                    throw new DataAccessException("Rollback failed");
+                }
+            }
+            throw e;
+        } finally {
+            if (connection != null) {
+                try {
+                    DataSourceUtils.releaseConnection(connection, dataSource);
+                } catch (Exception ex) {
+                    log.error("Failed to release connection or unbind resource", ex);
+                }
+            }
+        }
+    }
+}
+

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

@@ -1,13 +1,14 @@
 package com.techcourse.service;
 
 import com.interface21.dao.DataAccessException;
-import com.techcourse.config.DataSourceConfig;
+import com.interface21.jdbc.datasource.DataSourceUtils;
 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;
 
@@ -16,10 +17,12 @@ public class UserService {
     private static final Logger log = LoggerFactory.getLogger(UserService.class);
     private final UserDao userDao;
     private final UserHistoryDao userHistoryDao;
+    private final DataSource dataSource;
 
-    public UserService(final UserDao userDao, final UserHistoryDao userHistoryDao) {
+    public UserService(UserDao userDao, UserHistoryDao userHistoryDao, DataSource dataSource) {
         this.userDao = userDao;
         this.userHistoryDao = userHistoryDao;
+        this.dataSource = dataSource;
     }
 
     public User findById(final long id) {
@@ -32,26 +35,35 @@ public void insert(final User user) {
     }
 
     public void changePassword(final long id, final String newPassword, final String createBy) {
-        try (Connection connection = DataSourceConfig.getInstance().getConnection()) {
+        Connection connection = null;
+        try {
+            connection = DataSourceUtils.getConnection(dataSource);
             connection.setAutoCommit(false);
-            try {
-                final var user = userDao.findById(connection, id)
-                        .orElseThrow(() -> new IllegalArgumentException("사용자 정보가 존재하지 않습니다."));
-                user.changePassword(newPassword);
-                userDao.update(connection, user);
-                userHistoryDao.log(connection, new UserHistory(user, createBy));
-                connection.commit();
-            } catch (Exception e) {
+
+            final var user = userDao.findById(id)
+                    .orElseThrow(() -> new IllegalArgumentException("사용자 정보가 존재하지 않습니다."));
+            user.changePassword(newPassword);
+            userDao.update(user);
+            userHistoryDao.log(new UserHistory(user, createBy));
+
+            connection.commit();
+        } catch (Exception e) {
+            if (connection != null) {
                 try {
                     connection.rollback();
                 } catch (SQLException ex) {
                     log.error("Rollback failed", ex);
                 }
-                throw e;
             }
-        } catch (SQLException e) {
-            log.error(e.getMessage(), e);
             throw new DataAccessException(e);
+        } finally {
+            if (connection != null) {
+                try {
+                    DataSourceUtils.releaseConnection(connection, dataSource);
+                } catch (Exception ex) {
+                    log.error("Failed to release connection or unbind resource", ex);
+                }
+            }
         }
     }
 }

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

@@ -0,0 +1,11 @@
+package com.techcourse.service;
+
+import com.techcourse.domain.User;
+
+public interface UserServiceInterface {
+    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

@@ -4,7 +4,6 @@
 import com.interface21.jdbc.core.JdbcTemplate;
 import com.techcourse.dao.UserHistoryDao;
 import com.techcourse.domain.UserHistory;
-import java.sql.Connection;
 
 public class MockUserHistoryDao extends UserHistoryDao {
 
@@ -13,7 +12,7 @@ public MockUserHistoryDao(final JdbcTemplate jdbcTemplate) {
     }
 
     @Override
-    public void log(Connection connection, final UserHistory userHistory) {
+    public void log(final UserHistory userHistory) {
         throw new DataAccessException();
     }
 }

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

@@ -31,7 +31,8 @@ void setUp() {
     @Test
     void testChangePassword() {
         final var userHistoryDao = new UserHistoryDao(jdbcTemplate);
-        final var userService = new UserService(userDao, userHistoryDao);
+        final var appUserService = new AppUserService(userDao, userHistoryDao);
+        final var userService = new TxUserService(appUserService);
 
         final var newPassword = "qqqqq";
         final var createBy = "gugu";
@@ -46,13 +47,16 @@ 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

@@ -2,6 +2,7 @@
 
 import com.interface21.dao.DataAccessException;
 import com.interface21.dao.IncorrectResultSizeException;
+import com.interface21.jdbc.datasource.DataSourceUtils;
 import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
@@ -27,20 +28,10 @@ public void update(String sql, Object... parameters) {
         execute(PreparedStatement::executeUpdate, sql, parameters);
     }
 
-    public void update(Connection connection, String sql, Object... parameters) {
-        execute(connection, PreparedStatement::executeUpdate, sql, parameters);
-    }
-
     public <T> List<T> query(String sql, RowMapper<T> rowMapper, Object... parameters) {
         return execute((preparedStatement) -> executeQuery(preparedStatement, rowMapper), sql, parameters);
     }
 
-    public <T> List<T> query(Connection connection, String sql, RowMapper<T> rowMapper, Object... parameters) {
-        return execute(connection,
-                (preparedStatement) -> executeQuery(preparedStatement, rowMapper), sql, parameters
-        );
-    }
-
     private <T> List<T> executeQuery(PreparedStatement preparedStatement, RowMapper<T> rowMapper) throws SQLException {
         List<T> results = new ArrayList<>();
         try (ResultSet resultSet = preparedStatement.executeQuery()) {
@@ -56,30 +47,22 @@ public <T> Optional<T> queryForObject(String sql, RowMapper<T> rowMapper, Object
         return extractSingleResult(results);
     }
 
-    public <T> Optional<T> queryForObject(Connection connection, String sql, RowMapper<T> rowMapper,
-                                          Object... parameters) {
-        List<T> results = query(connection, sql, rowMapper, parameters);
-        return extractSingleResult(results);
-    }
-
     private <T> T execute(PreparedStatementCallback<T> preparedStatementCallback, String sql, Object... parameters) {
-        try (Connection connection = dataSource.getConnection()) {
-            return execute(connection, preparedStatementCallback, sql, parameters);
-        } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new DataAccessException(e);
-        }
-    }
-
-    private <T> T execute(Connection connection, PreparedStatementCallback<T> preparedStatementCallback, String sql,
-                          Object... parameters) {
-        try (PreparedStatement preparedStatement = connection.prepareStatement(sql)) {
-            log.debug("query : {}", sql);
-            setParameters(preparedStatement, parameters);
-            return preparedStatementCallback.doInPreparedStatement(preparedStatement);
+        Connection connection = null;
+        try {
+            connection = DataSourceUtils.getConnection(dataSource);
+            try (PreparedStatement preparedStatement = connection.prepareStatement(sql)) {
+                log.debug("query : {}", sql);
+                setParameters(preparedStatement, parameters);
+                return preparedStatementCallback.doInPreparedStatement(preparedStatement);
+            }
         } catch (SQLException e) {
             log.error(e.getMessage(), e);
             throw new DataAccessException(e);
+        } finally {
+            if (connection != null) {
+                DataSourceUtils.releaseConnection(connection, dataSource);
+            }
         }
     }
 

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

@@ -0,0 +1,7 @@
+package com.interface21.jdbc.core;
+
+@FunctionalInterface
+public interface TransactionCallback<T> {
+
+    T doInTransaction();
+}