[JDBC 라이브러리 구현하기 - 4단계] 주노(최준호) 미션 제출합니다.

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(long id) {
+        return userDao.findById(id);
+    }
+
+    @Override
+    public void insert(User user) {
+        userDao.insert(user);
+    }
+
+    @Override
+    public void changePassword(long id, String newPassword, 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.TransactionExecutor;
+
+public class TxUserService implements UserService {
+
+    private final UserService userService;
+    private final TransactionExecutor transactionExecutor;
+
+    public TxUserService(UserService userService, TransactionExecutor transactionExecutor) {
+        this.userService = userService;
+        this.transactionExecutor = transactionExecutor;
+    }
+
+    @Override
+    public User findById(long id) {
+        return transactionExecutor.executeWithResult(() -> userService.findById(id));
+    }
+
+    @Override
+    public void insert(User user) {
+        transactionExecutor.execute(() -> userService.insert(user));
+    }
+
+    @Override
+    public void changePassword(final long id, final String newPassword, final String createBy) {
+        transactionExecutor.execute(() -> userService.changePassword(id, newPassword, createBy));
+    }
+}

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

@@ -1,38 +1,10 @@
 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 org.springframework.transaction.TransactionExecutor;
-import org.springframework.transaction.TransactionManager;
 
-public class UserService {
+public interface UserService {
 
-    private final UserDao userDao;
-    private final UserHistoryDao userHistoryDao;
-    private final TransactionManager transactionManager;
-
-    public UserService(final TransactionManager transactionManager, final UserDao userDao, final UserHistoryDao userHistoryDao) {
-        this.userDao = userDao;
-        this.userHistoryDao = userHistoryDao;
-        this.transactionManager = transactionManager;
-    }
-
-    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) {
-        TransactionExecutor.execute(transactionManager, () -> {
-            final var user = findById(id);
-            user.changePassword(newPassword);
-            userDao.update(transactionManager.getConnection(), user);
-            userHistoryDao.log(transactionManager.getConnection(), new UserHistory(user, createBy));
-        });
-    }
+    User findById(final long id);
+    void insert(final User user);
+    void changePassword(final long id, final String newPassword, final String createBy);
 }

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

@@ -9,6 +9,7 @@
 import org.junit.jupiter.api.Test;
 import org.springframework.dao.DataAccessException;
 import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.transaction.TransactionExecutor;
 import org.springframework.transaction.TransactionManager;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -34,7 +35,7 @@ void setUp() {
     @Test
     void testChangePassword() {
         final var userHistoryDao = new UserHistoryDao(jdbcTemplate);
-        final var userService = new UserService(transactionManager, userDao, userHistoryDao);
+        final var userService = new AppUserService(userDao, userHistoryDao);
 
         final var newPassword = "qqqqq";
         final var createBy = "gugu";
@@ -47,13 +48,12 @@ void testChangePassword() {
 
     @Test
     void testTransactionRollback() {
-        // 트랜잭션 롤백 테스트를 위해 mock으로 교체
         final var userHistoryDao = new MockUserHistoryDao(jdbcTemplate);
-        final var userService = new UserService(transactionManager, userDao, userHistoryDao);
+        final var appUserService = new AppUserService(userDao, userHistoryDao);
+        final var userService = new TxUserService(appUserService, new TransactionExecutor(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));
 

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

@@ -2,24 +2,35 @@
 
 import org.springframework.dao.DataAccessException;
 
-import java.sql.SQLException;
+import java.util.function.Supplier;
 
 public class TransactionExecutor {
 
-    private TransactionExecutor() {
+    private final TransactionManager transactionManager;
+
+    public TransactionExecutor(TransactionManager transactionManager) {
+        this.transactionManager = transactionManager;
     }
 
-    public static void execute(final TransactionManager transactionManager, final Runnable runnable) {
+    public void execute(final Runnable runnable) {
         try {
             transactionManager.begin();
             runnable.run();
             transactionManager.commit();
         } catch (Exception e) {
-            try {
-                transactionManager.rollback();
-            } catch (SQLException ex) {
-                throw new DataAccessException(ex);
-            }
+            transactionManager.rollback();
+            throw new DataAccessException(e);
+        }
+    }
+
+    public <R> R executeWithResult(final Supplier<R> supplier) {
+        try {
+            transactionManager.begin();
+            R result = supplier.get();
+            transactionManager.commit();
+            return result;
+        } catch (Exception e) {
+            transactionManager.rollback();
             throw new DataAccessException(e);
         }
     }

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

@@ -1,42 +1,55 @@
 package org.springframework.transaction;
 
 import org.springframework.dao.DataAccessException;
+import org.springframework.jdbc.datasource.DataSourceUtils;
+import org.springframework.transaction.support.TransactionSynchronizationManager;
 
 import javax.sql.DataSource;
 import java.sql.Connection;
 import java.sql.SQLException;
 
 public class TransactionManager {
 
+    private final DataSource dataSource;
     private final Connection connection;
 
     public TransactionManager(DataSource dataSource) {
+        this.dataSource = dataSource;
+        this.connection = DataSourceUtils.getConnection(dataSource);
+    }
+
+    public void begin() {
         try {
-            this.connection = dataSource.getConnection();
+            connection.setAutoCommit(false);
         } catch (SQLException e) {
             throw new DataAccessException(e);
         }
     }
 
-    public TransactionManager(Connection connection) {
-        this.connection = connection;
-    }
-
-    public void begin() throws SQLException {
-        connection.setAutoCommit(false);
-    }
-
-    public void commit() throws SQLException {
-        connection.commit();
-        connection.close();
+    public void commit() {
+        try {
+            connection.commit();
+            this.close();
+        } catch (SQLException e) {
+            throw new DataAccessException(e);
+        }
     }
 
-    public void rollback() throws SQLException {
-        connection.rollback();
-        connection.close();
+    public void rollback() {
+        try {
+            connection.rollback();
+            this.close();
+        } catch (SQLException e) {
+            throw new DataAccessException(e);
+        }
     }
 
     public Connection getConnection() {
         return connection;
     }
+
+    public void close() {
+        DataSourceUtils.releaseConnection(connection, dataSource);
+        TransactionSynchronizationManager.unbindResource(dataSource);
+    }
 }

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

@@ -11,13 +11,16 @@ public abstract class TransactionSynchronizationManager {
     private TransactionSynchronizationManager() {}
 
     public static Connection getResource(DataSource key) {
-        return null;
+        return resources.get().getOrDefault(key, null);
     }
 
     public static void bindResource(DataSource key, Connection value) {
+        resources.get().put(key, value);
     }
 
     public static Connection unbindResource(DataSource key) {
-        return null;
+        Connection released = resources.get().remove(key);
+        resources.remove();
+        return released;
     }
 }