[JDBC 라이브러리 구현하기 - 4단계] 콩하나(최한빈) 미션 제출합니다.

README.md

@@ -17,3 +17,10 @@
 - [x] 트랜잭션 경계 설정을 할 수 있다.
   - [x] 서비스에서 커넥션을 가져온다.
   - [x] dao의 메소드를 호출할 때 커넥션을 전달한다.
+
+## 4.Transaction synchronization 적용하기
+- [x] Transaction synchronization 적용
+  - [x] DataSourceUtils를 사용해 connection 객체를 가져온다.
+  - [x] TransactionSynchronizationManager가 잘 동작하도록 구현한다.
+- [x] 트랜잭션 서비스 추상화
+  - [x] 비즈니스 로직과 데이터 액세스 로직 분리

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

@@ -22,46 +22,43 @@ public UserDao(final JdbcTemplate jdbcTemplate) {
         this.jdbcTemplate = jdbcTemplate;
     }
 
-    public void insert(final Connection connection, final User user) {
+    public void insert(final User user) {
         final var sql = "insert into users (account, password, email) values (?, ?, ?)";
 
-        jdbcTemplate.execute(connection, sql, user.getAccount(), user.getPassword(), user.getEmail());
+        jdbcTemplate.execute(sql, user.getAccount(), user.getPassword(), user.getEmail());
     }
 
-    public void update(final Connection connection, final User user) {
+    public void update(final User user) {
         final var sql = "update users set (account, password, email) = (?, ?, ?) where id = ?";
 
-        jdbcTemplate.execute(connection, sql, user.getAccount(), user.getPassword(), user.getEmail(), user.getId());
+        jdbcTemplate.execute(sql, user.getAccount(), user.getPassword(), user.getEmail(), user.getId());
     }
 
-    public List<User> findAll(final Connection connection) {
+    public List<User> findAll() {
         final var sql = "select id, account, password, email from users";
 
-        return jdbcTemplate.findAll(connection,
-                sql,
+        return jdbcTemplate.findAll(sql,
                 rs -> new User(rs.getLong("id"),
                         rs.getString("account"),
                         rs.getString("password"),
                         rs.getString("email")));
     }
 
-    public User findById(final Connection connection, final Long id) {
+    public User findById(final Long id) {
         final var sql = "select id, account, password, email from users where id = ?";
 
-        return jdbcTemplate.find(connection,
-                sql,
+        return jdbcTemplate.find(sql,
                 rs -> new User(rs.getLong("id"),
                         rs.getString("account"),
                         rs.getString("password"),
                         rs.getString("email")),
                 id);
     }
 
-    public User findByAccount(final Connection connection, final String account) {
+    public User findByAccount(final String account) {
         final var sql = "select id, account, password, email from users where account = ?";
 
-        return jdbcTemplate.find(connection,
-                sql,
+        return jdbcTemplate.find(sql,
                 rs -> new User(rs.getLong("id"),
                         rs.getString("account"),
                         rs.getString("password"),

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

@@ -21,10 +21,10 @@ public UserHistoryDao(final JdbcTemplate jdbcTemplate) {
         this.jdbcTemplate = jdbcTemplate;
     }
 
-    public void log(final 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.execute(connection, sql, userHistory.getUserId(), userHistory.getAccount(),
+        jdbcTemplate.execute(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 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));
+    }
+}

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

@@ -1,9 +1,7 @@
 package com.techcourse.service;
 
-import java.sql.Connection;
-
 @FunctionalInterface
 public interface TransactionalDaoExecutor<T> {
 
-    T execute(final Connection connection);
+    T execute();
 }

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

@@ -0,0 +1,62 @@
+package com.techcourse.service;
+
+import com.techcourse.domain.User;
+import java.sql.Connection;
+import java.sql.SQLException;
+import javax.sql.DataSource;
+import org.springframework.jdbc.core.JdbcTemplateException;
+import org.springframework.jdbc.datasource.DataSourceUtils;
+
+public class TxUserService implements UserService {
+
+    private final UserService userService;
+    private final DataSource dataSource;
+
+    public TxUserService(final UserService userService, final DataSource dataSource) {
+        this.userService = userService;
+        this.dataSource = dataSource;
+    }
+
+    @Override
+    public User findById(final long id) {
+        return doService(() -> userService.findById(id));
+    }
+
+    private <T> T doService(final TransactionalDaoExecutor<T> executor) {
+        try {
+            return doDaoWithTransaction(executor);
+        } catch (SQLException e) {
+            throw new DataBaseAccessException(e.getMessage());
+        }
+    }
+
+    private <T> T doDaoWithTransaction(final TransactionalDaoExecutor<T> executor) throws SQLException {
+        Connection connection = DataSourceUtils.getConnection(dataSource);
+        connection.setAutoCommit(false);
+        try {
+            return executor.execute();
+        } catch (JdbcTemplateException e) {
+            connection.rollback();
+            throw new DataBaseAccessException(e.getMessage());
+        } finally {
+            connection.setAutoCommit(true);
+            DataSourceUtils.releaseConnection(connection, dataSource);
+        }
+    }
+
+    @Override
+    public void insert(final User user) {
+        doService(() -> {
+            userService.insert(user);
+            return null;
+        });
+    }
+
+    @Override
+    public void changePassword(final long id, final String newPassword, final String createBy) {
+        doService(() -> {
+            userService.changePassword(id, newPassword, createBy);
+            return null;
+        });
+    }
+}

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

@@ -1,67 +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;
-import java.sql.Connection;
-import java.sql.SQLException;
-import javax.sql.DataSource;
-import org.springframework.jdbc.core.JdbcTemplateException;
 
-public class UserService {
+public interface UserService {
 
-    private final DataSource dataSource;
-    private final UserDao userDao;
-    private final UserHistoryDao userHistoryDao;
+    User findById(final long id);
 
-    public UserService(final DataSource dataSource, final UserDao userDao, final UserHistoryDao userHistoryDao) {
-        this.dataSource = dataSource;
-        this.userDao = userDao;
-        this.userHistoryDao = userHistoryDao;
-    }
+    void insert(final User user);
 
-    public User findById(final long id) {
-        return doService(connection -> userDao.findById(connection, id));
-    }
-
-    private <T> T doService(final TransactionalDaoExecutor<T> executor) {
-        try {
-            Connection connection = dataSource.getConnection();
-            return doDaoWithTransaction(executor, connection);
-        } catch (SQLException e) {
-            throw new DataBaseAccessException(e.getMessage());
-        }
-    }
-
-    private <T> T doDaoWithTransaction(final TransactionalDaoExecutor<T> executor,
-                                       final Connection connection) throws SQLException {
-        connection.setAutoCommit(false);
-        try {
-            return executor.execute(connection);
-        } catch (JdbcTemplateException e) {
-            connection.rollback();
-            throw new DataBaseAccessException(e.getMessage());
-        } finally {
-            connection.setAutoCommit(true);
-        }
-    }
-
-    public void insert(final User user) {
-        doService(connection -> {
-            userDao.insert(connection, user);
-            return null;
-        });
-    }
-
-    public void changePassword(final long id, final String newPassword, final String createBy) {
-        final var user = findById(id);
-        user.changePassword(newPassword);
-
-        doService(connection -> {
-            userDao.update(connection, user);
-            userHistoryDao.log(connection, new UserHistory(user, createBy));
-            return null;
-        });
-    }
+    void changePassword(final long id, final String newPassword, final String createBy);
 }

app/src/test/java/com/techcourse/dao/UserDaoTest.java

@@ -27,7 +27,7 @@ void setup() throws SQLException {
         connection = dataSource.getConnection();
         userDao = new UserDao(dataSource);
         final var user = new User("gugu", "password", "[email protected]");
-        userDao.insert(connection, user);
+        userDao.insert(user);
     }
 
     @AfterEach
@@ -39,22 +39,22 @@ void initTable() throws SQLException {
 
     @Test
     void findAll() throws SQLException {
-        final var users = userDao.findAll(connection);
+        final var users = userDao.findAll();
 
         assertThat(users).isNotEmpty();
     }
 
     @Test
     void findById() {
-        final var user = userDao.findById(connection, 1L);
+        final var user = userDao.findById(1L);
 
         assertThat(user.getAccount()).isEqualTo("gugu");
     }
 
     @Test
     void findByAccount() {
         final var account = "gugu";
-        final var user = userDao.findByAccount(connection, account);
+        final var user = userDao.findByAccount(account);
 
         assertThat(user.getAccount()).isEqualTo(account);
     }
@@ -63,22 +63,21 @@ void findByAccount() {
     void insert() {
         final var account = "insert-gugu";
         final var user = new User(account, "password", "[email protected]");
-        userDao.insert(connection, user);
+        userDao.insert(user);
 
-        final var actual = userDao.findById(connection, 2L);
-
-        assertThat(actual.getAccount()).isEqualTo(account);
+        final var actual = userDao.findByAccount("insert-gugu");
+        assertThat(actual).isNotNull();
     }
 
     @Test
     void update() {
         final var newPassword = "password99";
-        final var user = userDao.findById(connection, 1L);
+        final var user = userDao.findById(1L);
         user.changePassword(newPassword);
 
-        userDao.update(connection, user);
+        userDao.update(user);
 
-        final var actual = userDao.findById(connection, 1L);
+        final var actual = userDao.findById(1L);
 
         assertThat(actual.getPassword()).isEqualTo(newPassword);
     }

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

@@ -13,7 +13,7 @@ public MockUserHistoryDao(final JdbcTemplate jdbcTemplate) {
     }
 
     @Override
-    public void log(final Connection connection, final UserHistory userHistory) {
+    public void log(final UserHistory userHistory) {
         throw new JdbcTemplateException("공습 경보!!!") {
             @Override
             public String getMessage() {

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

@@ -21,20 +21,20 @@ class UserServiceTest {
     private DataSource dataSource;
 
     @BeforeEach
-    void setUp() throws SQLException {
+    void setUp() {
         this.dataSource = DataSourceConfig.getInstance();
         this.jdbcTemplate = new JdbcTemplate(dataSource);
         this.userDao = new UserDao(jdbcTemplate);
 
         DatabasePopulatorUtils.execute(dataSource);
         final var user = new User("gugu", "password", "[email protected]");
-        userDao.insert(dataSource.getConnection(), user);
+        userDao.insert(user);
     }
 
     @Test
     void testChangePassword() {
         final var userHistoryDao = new UserHistoryDao(jdbcTemplate);
-        final var userService = new UserService(dataSource, userDao, userHistoryDao);
+        final var userService = new AppUserService(userDao, userHistoryDao);
 
         final var newPassword = "qqqqq";
         final var createBy = "gugu";
@@ -49,7 +49,10 @@ void testChangePassword() {
     void testTransactionRollback() {
         // 트랜잭션 롤백 테스트를 위해 mock으로 교체
         final var userHistoryDao = new MockUserHistoryDao(jdbcTemplate);
-        final var userService = new UserService(dataSource, userDao, userHistoryDao);
+        // 애플리케이션 서비스
+        final var appUserService = new AppUserService(userDao, userHistoryDao);
+        // 트랜잭션 서비스 추상화
+        final var userService = new TxUserService(appUserService, dataSource);
 
         final var newPassword = "newPassword";
         final var createBy = "gugu";