[JDBC 라이브러리 구현하기 - 4단계] 말랑(신동훈) 미션 제출합니다.

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

@@ -38,11 +38,6 @@ public void update(final User user) {
         jdbcTemplate.execute(sql, user.getAccount(), user.getPassword(), user.getEmail(), user.getId());
     }
 
-    public void update(Connection conn, final User user) {
-        final var sql = "update users set account = ?, password = ?, email = ? where id = ?";
-        jdbcTemplate.execute(conn, 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.queryForList(sql, userRowMapper);

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

@@ -1,7 +1,6 @@
 package com.techcourse.dao;
 
 import com.techcourse.domain.UserHistory;
-import java.sql.Connection;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.jdbc.core.JdbcTemplate;
@@ -16,9 +15,9 @@ public UserHistoryDao(final JdbcTemplate jdbcTemplate) {
         this.jdbcTemplate = jdbcTemplate;
     }
 
-    public void log(Connection conn, 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(conn, sql,
+        jdbcTemplate.execute(sql,
                 userHistory.getUserId(),
                 userHistory.getAccount(),
                 userHistory.getPassword(),

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/TxTemplateUserService.java

@@ -0,0 +1,29 @@
+package com.techcourse.service;
+
+import com.techcourse.domain.User;
+import org.springframework.transaction.support.TxTemplate;
+
+public class TxTemplateUserService implements UserService {
+
+    private final UserService delegate;
+    private final TxTemplate txTemplate;
+
+    public TxTemplateUserService(UserService delegate, TxTemplate txTemplate) {
+        this.delegate = delegate;
+        this.txTemplate = txTemplate;
+    }
+
+    public User findById(final long id) {
+        return delegate.findById(id);
+    }
+
+    public void insert(final User user) {
+        delegate.insert(user);
+    }
+
+    public void changePassword(final long id, final String newPassword, final String createBy) {
+        txTemplate.execute(() -> {
+            delegate.changePassword(id, newPassword, createBy);
+        });
+    }
+}

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

@@ -0,0 +1,44 @@
+package com.techcourse.service;
+
+import com.techcourse.config.DataSourceConfig;
+import com.techcourse.domain.User;
+import java.sql.Connection;
+import java.sql.SQLException;
+import javax.sql.DataSource;
+import org.springframework.dao.DataAccessException;
+import org.springframework.jdbc.datasource.DataSourceUtils;
+
+public class TxUserService implements UserService {
+
+    private final UserService delegate;
+
+    public TxUserService(UserService delegate) {
+        this.delegate = delegate;
+    }
+
+    public User findById(final long id) {
+        return delegate.findById(id);
+    }
+
+    public void insert(final User user) {
+        delegate.insert(user);
+    }
+
+    public void changePassword(final long id, final String newPassword, final String createBy) {
+        DataSource dataSource = DataSourceConfig.getInstance();
+        try (Connection conn = DataSourceUtils.getConnection(dataSource)) {
+            try {
+                conn.setAutoCommit(false);
+                delegate.changePassword(id, newPassword, createBy);
+                conn.commit();
+            } catch (SQLException e) {
+                conn.rollback();
+                throw new DataAccessException(e);
+            } finally {
+                DataSourceUtils.releaseConnection(conn, dataSource);
+            }
+        } catch (SQLException e) {
+            throw new DataAccessException(e);
+        }
+    }
+}

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

@@ -1,49 +1,12 @@
 package com.techcourse.service;
 
-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.springframework.dao.DataAccessException;
 
-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) {
-        DataSource dataSource = DataSourceConfig.getInstance();
-        try (Connection conn = dataSource.getConnection()) {
-            try {
-                conn.setAutoCommit(false);
-                final var user = findById(id);
-                user.changePassword(newPassword);
-                userDao.update(conn, user);
-                userHistoryDao.log(conn, new UserHistory(user, createBy));
-                conn.commit();
-            } catch (Exception e) {
-                conn.rollback();
-                throw new DataAccessException(e);
-            }
-        } catch (SQLException e) {
-            throw new DataAccessException(e);
-        }
-    }
+    void changePassword(final long id, final String newPassword, final String createBy);
 }

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

@@ -2,7 +2,6 @@
 
 import com.techcourse.dao.UserHistoryDao;
 import com.techcourse.domain.UserHistory;
-import java.sql.Connection;
 import org.springframework.dao.DataAccessException;
 import org.springframework.jdbc.core.JdbcTemplate;
 
@@ -13,7 +12,7 @@ public MockUserHistoryDao(final JdbcTemplate jdbcTemplate) {
     }
 
     @Override
-    public void log(Connection conn, final UserHistory userHistory) {
+    public void log(final UserHistory userHistory) {
         throw new DataAccessException();
     }
 }

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

@@ -8,10 +8,12 @@
 import com.techcourse.dao.UserHistoryDao;
 import com.techcourse.domain.User;
 import com.techcourse.support.jdbc.init.DatabasePopulatorUtils;
+import javax.sql.DataSource;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 import org.springframework.dao.DataAccessException;
 import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.transaction.support.TxTemplate;
 
 class UserServiceTest {
 
@@ -31,7 +33,7 @@ void setUp() {
     @Test
     void testChangePassword() {
         final var userHistoryDao = new UserHistoryDao(jdbcTemplate);
-        final var userService = new UserService(userDao, userHistoryDao);
+        final var userService = new TxUserService(new AppUserService(userDao, userHistoryDao));
 
         final var newPassword = "qqqqq";
         final var createBy = "gugu";
@@ -46,7 +48,30 @@ 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";
+        // 트랜잭션이 정상 동작하는지 확인하기 위해 의도적으로 MockUserHistoryDao에서 예외를 발생시킨다.
+        assertThrows(DataAccessException.class,
+                () -> userService.changePassword(1L, newPassword, createBy));
+
+        final var actual = userService.findById(1L);
+
+        assertThat(actual.getPassword()).isNotEqualTo(newPassword);
+    }
+
+    @Test
+    void testTransactionWithTemplateRollback() {
+        // 트랜잭션 롤백 테스트를 위해 mock으로 교체
+        final var userHistoryDao = new MockUserHistoryDao(jdbcTemplate);
+        // 애플리케이션 서비스
+        final var appUserService = new AppUserService(userDao, userHistoryDao);
+        // 트랜잭션 서비스 추상화
+        final var userService = new TxTemplateUserService(appUserService, new TxTemplate(DataSourceConfig.getInstance()));
 
         final var newPassword = "newPassword";
         final var createBy = "gugu";

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

@@ -9,6 +9,8 @@
 import javax.sql.DataSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.dao.DataAccessException;
+import org.springframework.jdbc.datasource.DataSourceUtils;
 
 public class JdbcTemplate {
 
@@ -24,12 +26,9 @@ public void execute(String sql, Object... params) {
         execute(sql, PreparedStatement::executeUpdate, params);
     }
 
-    public void execute(Connection conn, String sql, Object... params) {
-        execute(conn, sql, PreparedStatement::executeUpdate, params);
-    }
-
     public <T> T queryForObject(String sql, RowMapper<T> rowMapper, Object... params) {
-        return execute(sql, pstmt -> {
+        Connection connection = DataSourceUtils.getConnection(dataSource);
+        return execute(connection, sql, pstmt -> {
             ResultSet resultSet = pstmt.executeQuery();
             if (resultSet.next()) {
                 return rowMapper.mapRow(resultSet);
@@ -39,7 +38,8 @@ public <T> T queryForObject(String sql, RowMapper<T> rowMapper, Object... params
     }
 
     public <T> List<T> queryForList(String sql, RowMapper<T> rowMapper, Object... params) {
-        return execute(sql, pstmt -> {
+        Connection connection = DataSourceUtils.getConnection(dataSource);
+        return execute(connection, sql, pstmt -> {
             ResultSet resultSet = pstmt.executeQuery();
             List<T> result = new ArrayList<>();
             while (resultSet.next()) {
@@ -50,21 +50,21 @@ public <T> List<T> queryForList(String sql, RowMapper<T> rowMapper, Object... pa
     }
 
     private <T> T execute(String sql, PreparedStatementFunction<T> function, Object... params) {
-        try (Connection connection = dataSource.getConnection();
-             PreparedStatement pstmt = preparedStatementWithParams(connection, sql, params)) {
+        Connection connection = DataSourceUtils.getConnection(dataSource);
+        try (PreparedStatement pstmt = preparedStatementWithParams(connection, sql, params)) {
             return function.execute(pstmt);
         } catch (Exception e) {
             log.error(e.getMessage(), e);
-            throw new RuntimeException(e);
+            throw new DataAccessException(e);
         }
     }
 
     private <T> T execute(Connection conn, String sql, PreparedStatementFunction<T> function, Object... params) {
         try (PreparedStatement pstmt = preparedStatementWithParams(conn, sql, params)) {
             return function.execute(pstmt);
-        } catch (Exception e) {
+        } catch (SQLException e) {
             log.error(e.getMessage(), e);
-            throw new RuntimeException(e);
+            throw new DataAccessException(e);
         }
     }
 
@@ -79,6 +79,6 @@ private PreparedStatement preparedStatementWithParams(Connection con, String sql
     }
 
     private interface PreparedStatementFunction<T> {
-        T execute(PreparedStatement pstmt) throws Exception;
+        T execute(PreparedStatement pstmt) throws SQLException;
     }
 }

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

@@ -17,7 +17,6 @@ public static Connection getConnection(DataSource dataSource) throws CannotGetJd
         if (connection != null) {
             return connection;
         }
-
         try {
             connection = dataSource.getConnection();
             TransactionSynchronizationManager.bindResource(dataSource, connection);
@@ -30,6 +29,7 @@ public static Connection getConnection(DataSource dataSource) throws CannotGetJd
     public static void releaseConnection(Connection connection, DataSource dataSource) {
         try {
             connection.close();
+            TransactionSynchronizationManager.unbindResource(dataSource);
         } catch (SQLException ex) {
             throw new CannotGetJdbcConnectionException("Failed to close JDBC Connection");
         }

jdbc/src/main/java/org/springframework/transaction/support/TransactionSynchronizationManager.java

@@ -1,23 +1,39 @@
 package org.springframework.transaction.support;
 
-import javax.sql.DataSource;
 import java.sql.Connection;
+import java.util.HashMap;
 import java.util.Map;
+import javax.annotation.Nullable;
+import javax.sql.DataSource;
 
 public abstract class TransactionSynchronizationManager {
 
     private static final ThreadLocal<Map<DataSource, Connection>> resources = new ThreadLocal<>();
 
-    private TransactionSynchronizationManager() {}
+    private TransactionSynchronizationManager() {
+    }
 
+    @Nullable
     public static Connection getResource(DataSource key) {
-        return null;
+        Map<DataSource, Connection> dataSourceConnectionMap = resources.get();
+        if (dataSourceConnectionMap == null) {
+            return null;
+        }
+        return dataSourceConnectionMap.get(key);
     }
 
     public static void bindResource(DataSource key, Connection value) {
+        resources.set(new HashMap<>() {{
+            put(key, value);
+        }});
     }
 
     public static Connection unbindResource(DataSource key) {
-        return null;
+        Map<DataSource, Connection> dataSourceConnectionMap = resources.get();
+        Connection remove = dataSourceConnectionMap.remove(key);
+        if (dataSourceConnectionMap.isEmpty()) {
+            resources.remove();
+        }
+        return remove;
     }
 }