[JDBC 4단계] 민트(유재민) 미션 제출합니다.

README.md

@@ -46,4 +46,30 @@
 - [x] 공유자원 Singleton vs static
 - [x] JdbcTemplate 테스트 작성
 - [x] JdbcTemplate의 executeQuery 중복 제거
-- [x] TransactionTemplate catch 절 final
+- [x] TransactionTemplate catch 절 final
+
+### 3차
+- [x] EOF 해결(TransactionTemplateTest, PreparedStatementCreatorTest)
+
+## 4단계 리뷰
+- [x] AppUserService 생성자 빈칸 제거 
+- [x] TxUserService TransactionTemplate 생성자로 받도록 수정
+- [x] TransactionTemplate 반환값 없는 메서드 만들기
+- [x] Nullable TypeQualifierNickname 어떤 효과?
+- [x] TransactionSyncrhonizationManager 중복되는 get() 제거
+- [x] ConnectionManager 제거 리팩토링
+  - 현재 흐름
+    - Transaction
+      1. TransactionTemplate에게 요청
+      2. DataSourceUtils -> Connection 생성 및 ThreadLocal 등록
+      3. TransactionTemplate 트랜잭션 시작하며 로직 수행 -> JdbcTemplate 호출
+      4. JdbcTemplate은 ConnectionManager에게 Connection 요청
+      5. ConnectionManager는 ThreadLocal의 Connection 반환
+      6. JdbcTemplate DB 접근 끝
+      7. TransactionTemplate 로직 끝 -> 커밋
+      8. DataSourceUtils 통해 Connection 자원 반환, ThreadLocal에서도 제거
+    - Transaction X
+      1. JdbcTemplate은 ConnectionManager에게 Connection 요청
+      2. ConnectionManager는 Connection 새로 생성해서 반환
+      3. JdbcTemplate DB 접근 끝 
+      4. ConnectionManager가 Connection 자원 반환

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

@@ -1,6 +1,8 @@
 package com.techcourse.dao;
 
 import com.techcourse.domain.User;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.core.RowMapper;
 
@@ -18,6 +20,8 @@ public class UserDao {
         return new User(id, account, password, email);
     };
 
+    private static final Logger log = LoggerFactory.getLogger(UserDao.class);
+
     private final JdbcTemplate jdbcTemplate;
 
     public UserDao(final DataSource dataSource) {

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

@@ -0,0 +1,33 @@
+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)
+                .orElseThrow(() -> new IllegalArgumentException("유저가 존재하지 않습니다."));
+    }
+
+    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/TxUserService.java

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

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

@@ -1,42 +1,10 @@
 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 org.springframework.transaction.support.TransactionTemplate;
 
-import javax.sql.DataSource;
+public interface UserService {
 
-public class UserService {
-
-    private final UserDao userDao;
-    private final UserHistoryDao userHistoryDao;
-    private final TransactionTemplate transactionTemplate;
-
-    public UserService(final UserDao userDao, final UserHistoryDao userHistoryDao) {
-        this.userDao = userDao;
-        this.userHistoryDao = userHistoryDao;
-        final DataSource dataSource = DataSourceConfig.getInstance();
-        this.transactionTemplate = new TransactionTemplate(dataSource);
-    }
-
-    public User findById(final long id) {
-        return userDao.findById(id)
-                .orElseThrow(() -> new IllegalArgumentException("유저가 존재하지 않습니다."));
-    }
-
-    public void insert(final User user) {
-        userDao.insert(user);
-    }
-
-    public void changePassword(final long id, final String newPassword, final String createBy) {
-        transactionTemplate.executeWithTransaction(() -> {
-            final var user = findById(id);
-            user.changePassword(newPassword);
-            userDao.update(user);
-            userHistoryDao.log(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 +9,9 @@
 import org.junit.jupiter.api.Test;
 import org.springframework.dao.DataAccessException;
 import org.springframework.jdbc.core.JdbcTemplate;
+import org.springframework.transaction.support.TransactionTemplate;
+
+import javax.sql.DataSource;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertAll;
@@ -18,11 +21,14 @@ class UserServiceTest {
 
     private JdbcTemplate jdbcTemplate;
     private UserDao userDao;
+    private TransactionTemplate transactionTemplate;
 
     @BeforeEach
     void setUp() {
-        this.jdbcTemplate = new JdbcTemplate(DataSourceConfig.getInstance());
+        DataSource dataSource = DataSourceConfig.getInstance();
+        this.jdbcTemplate = new JdbcTemplate(dataSource);
         this.userDao = new UserDao(jdbcTemplate);
+        this.transactionTemplate = new TransactionTemplate(dataSource);
 
         DatabasePopulatorUtils.execute(DataSourceConfig.getInstance());
         final var user = new User("gugu", "password", "[email protected]");
@@ -32,7 +38,7 @@ void setUp() {
     @Test
     void testChangePassword() {
         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";
@@ -47,7 +53,10 @@ 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, transactionTemplate);
 
         final User user = userDao.findById(1L).get();
         final var oldPassword = user.getPassword();

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

@@ -2,6 +2,7 @@
 
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.jdbc.datasource.DataSourceUtils;
 
 import javax.sql.DataSource;
 import java.sql.Connection;
@@ -17,25 +18,25 @@ public class JdbcTemplate {
     private static final Logger log = LoggerFactory.getLogger(JdbcTemplate.class);
 
     private final PreparedStatementCreator preparedStatementCreator = new PreparedStatementCreator();
-    private final ConnectionManager connectionManager;
+    private final DataSource dataSource;
 
     public JdbcTemplate(final DataSource dataSource) {
-        this.connectionManager = new ConnectionManager(dataSource);
+        this.dataSource = dataSource;
     }
 
     public <T> Optional<T> queryForObject(final String sql, final RowMapper<T> rowMapper, final Object... args) {
         return executeQuery(sql, preparedStatement -> SingleResult.convert(getQueryResult(rowMapper, preparedStatement)), args);
     }
 
     private <T> T executeQuery(final String sql, final SqlExecutor<T> executor, final Object... args) {
-        final Connection connection = connectionManager.getConnection();
+        final Connection connection = DataSourceUtils.getConnection(dataSource);
         try (final PreparedStatement preparedStatement = preparedStatementCreator.createPreparedStatement(connection, sql, args)) {
             return executor.execute(preparedStatement);
         } catch (final SQLException e) {
             log.error(e.getMessage(), e);
             throw new RuntimeException(e);
         } finally {
-            connectionManager.closeNotTransactional(connection);
+            DataSourceUtils.closeNotTransactional(dataSource, connection);
         }
     }
 

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

@@ -13,25 +13,39 @@ public abstract class DataSourceUtils {
     private DataSourceUtils() {}
 
     public static Connection getConnection(DataSource dataSource) throws CannotGetJdbcConnectionException {
-        Connection connection = TransactionSynchronizationManager.getResource(dataSource);
-        if (connection != null) {
-            return connection;
+        if (TransactionSynchronizationManager.hasResource(dataSource)) {
+            return TransactionSynchronizationManager.getResource(dataSource);
         }
 
         try {
-            connection = dataSource.getConnection();
+            Connection connection = dataSource.getConnection();
             TransactionSynchronizationManager.bindResource(dataSource, connection);
             return connection;
         } catch (SQLException ex) {
             throw new CannotGetJdbcConnectionException("Failed to obtain JDBC Connection", ex);
         }
     }
 
-    public static void releaseConnection(Connection connection, DataSource dataSource) {
+    public static void releaseConnection(Connection connection) {
         try {
             connection.close();
         } catch (SQLException ex) {
             throw new CannotGetJdbcConnectionException("Failed to close JDBC Connection");
         }
     }
+
+    public static void closeNotTransactional(final DataSource dataSource, final Connection connection) {
+        if (isTransactional(dataSource, connection)) {
+            return;
+        }
+        TransactionSynchronizationManager.unbindResource(dataSource);
+        releaseConnection(connection);
+    }
+
+    private static boolean isTransactional(final DataSource dataSource, final Connection connection) {
+        if (TransactionSynchronizationManager.hasResource(dataSource)) {
+            return TransactionSynchronizationManager.getResource(dataSource) == connection;
+        }
+        return false;
+    }
 }

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

@@ -0,0 +1,14 @@
+package org.springframework.transaction.support;
+
+import javax.annotation.Nonnull;
+import javax.annotation.meta.When;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.METHOD)
+@Retention(RetentionPolicy.RUNTIME)
+@Nonnull(when = When.MAYBE)
+public @interface Nullable {
+}

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

@@ -1,7 +1,8 @@
 package org.springframework.transaction.support;
 
 @FunctionalInterface
-public interface TransactionCallback {
+public interface TransactionCallback<T> {
 
-    void execute();
+    @Nullable
+    T execute();
 }