refactor: JdbcTemplate의 반복을 줄이고,dao에서 커넥션을 보내지 않도록 수정함

woowacourse · Oct 11, 2023 · 7ff7f19 · 7ff7f19
1 parent 2347c91
commit 7ff7f19
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Showing 4 changed files with 29 additions and 43 deletions.
diff --git a/app/src/main/java/com/techcourse/dao/UserDao.java b/app/src/main/java/com/techcourse/dao/UserDao.java
@@ -1,10 +1,8 @@
 package com.techcourse.dao;
 
-import com.techcourse.config.DataSourceConfig;
 import com.techcourse.domain.User;
 import org.springframework.jdbc.core.JdbcTemplate;
 import org.springframework.jdbc.core.RowMapper;
-import org.springframework.jdbc.datasource.DataSourceUtils;
 
 import java.util.List;
 
@@ -35,7 +33,7 @@ public void update(final User user) {
         final var sql = "update users set account = ? , password = ? , email = ? where id = ?";
         final Object[] parameters = {user.getAccount(), user.getPassword(), user.getEmail(), user.getId()};
 
-        jdbcTemplate.update(DataSourceUtils.getConnection(DataSourceConfig.getInstance()), sql, parameters);
+        jdbcTemplate.update(sql, parameters);
     }
 
     public List<User> findAll() {

diff --git a/app/src/main/java/com/techcourse/dao/UserHistoryDao.java b/app/src/main/java/com/techcourse/dao/UserHistoryDao.java
@@ -1,9 +1,7 @@
 package com.techcourse.dao;
 
-import com.techcourse.config.DataSourceConfig;
 import com.techcourse.domain.UserHistory;
 import org.springframework.jdbc.core.JdbcTemplate;
-import org.springframework.jdbc.datasource.DataSourceUtils;
 
 public class UserHistoryDao {
 
@@ -17,6 +15,6 @@ public void log(final UserHistory userHistory) {
         final var sql = "insert into user_history (user_id, account, password, email, created_at, created_by) values (?, ?, ?, ?, ?, ?)";
         final Object[] parameters = {userHistory.getUserId(), userHistory.getAccount(), userHistory.getPassword(), userHistory.getEmail(), userHistory.getCreatedAt(), userHistory.getCreateBy()};
 
-        jdbcTemplate.update(DataSourceUtils.getConnection(DataSourceConfig.getInstance()), sql, parameters);
+        jdbcTemplate.update(sql, parameters);
     }
 }
diff --git a/jdbc/src/main/java/org/springframework/jdbc/core/JdbcTemplate.java b/jdbc/src/main/java/org/springframework/jdbc/core/JdbcTemplate.java
@@ -3,6 +3,7 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.dao.DataAccessException;
+import org.springframework.jdbc.datasource.DataSourceUtils;
 
 import javax.sql.DataSource;
 import java.sql.Connection;
@@ -23,57 +24,37 @@ public JdbcTemplate(final DataSource dataSource) {
     }
 
     public int update(final String sql, final Object... parameters) {
-        try (Connection conn = dataSource.getConnection();
-             PreparedStatement pstmt = PreparedStateUtil.makeStatement(conn, sql, parameters)
-        ) {
-            log.debug("Execute Update - query : {}", sql);
-            return pstmt.executeUpdate();
-        } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new DataAccessException(e);
-        }
+        return executeQuery(sql, PreparedStatement::executeUpdate, parameters);
     }
 
-    public int update(final Connection conn, final String sql, final Object[] parameters) {
-        try (PreparedStatement pstmt = PreparedStateUtil.makeStatement(conn, sql, parameters)){
-            log.debug("Execute Update - query : {}", sql);
-            return pstmt.executeUpdate();
+    private <T> T executeQuery(final String sql, final PreparedStateExecutor<T> executor, final Object... parameters) {
+        final Connection conn = DataSourceUtils.getConnection(dataSource);
+        try (PreparedStatement pstmt = PreparedStateUtil.makeStatement(conn, sql, parameters)) {
+            log.debug("Execute - query : {}", sql);
+            return executor.execute(pstmt);
         } catch (SQLException e) {
+            log.error(e.getMessage(), e);
             throw new DataAccessException(e);
+        } finally {
+            DataSourceUtils.releaseConnection(conn, dataSource);
         }
     }
 
     public <T> T queryForObject(final String sql, final RowMapper<T> rowMapper, final Object... parameters) {
-        try (Connection conn = dataSource.getConnection();
-             PreparedStatement pstmt = PreparedStateUtil.makeStatement(conn, sql, parameters);
-             ResultSet rs = pstmt.executeQuery()
-        ) {
-            log.debug("Execute Query -query : {}", sql);
-            return SingleResult.makeSingleResultFrom(makeResults(rowMapper, rs));
-        } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new DataAccessException(e);
-        }
+        return executeQuery(sql, preparedStatement -> SingleResult.makeSingleResultFrom(makeResults(rowMapper, preparedStatement)), parameters);
     }
 
-    private <T> List<T> makeResults(final RowMapper<T> rowMapper, final ResultSet rs) throws SQLException {
+    private <T> List<T> makeResults(final RowMapper<T> rowMapper, final PreparedStatement preparedStatement) throws SQLException {
         List<T> list = new ArrayList<>();
-        while (rs.next()) {
-            list.add(rowMapper.mapping(rs));
+        try (final ResultSet resultSet = preparedStatement.executeQuery()) {
+            while (resultSet.next()) {
+                list.add(rowMapper.mapping(resultSet));
+            }
         }
         return list;
     }
 
-    public <T> List<T> queryForList(final String sql, final RowMapper<T> rowMapper) {
-        try (Connection conn = dataSource.getConnection();
-             PreparedStatement pstmt = conn.prepareStatement(sql);
-             ResultSet rs = pstmt.executeQuery()
-        ) {
-            log.debug("Execute Query - query : {}", sql);
-            return makeResults(rowMapper, rs);
-        } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new DataAccessException(e);
-        }
+    public <T> List<T> queryForList(final String sql, final RowMapper<T> rowMapper, final Object... parameters) {
+        return executeQuery(sql, preparedStatement -> makeResults(rowMapper, preparedStatement), parameters);
     }
 }
diff --git a/jdbc/src/main/java/org/springframework/jdbc/core/PreparedStateExecutor.java b/jdbc/src/main/java/org/springframework/jdbc/core/PreparedStateExecutor.java
@@ -0,0 +1,9 @@
+package org.springframework.jdbc.core;
+
+import java.sql.PreparedStatement;
+import java.sql.SQLException;
+
+public interface PreparedStateExecutor<T> {
+
+    T execute(final PreparedStatement preparedStatement) throws SQLException;
+}