[JDBC 라이브러리 구현하기 - 2단계] 디노(신종화) 미션 제출합니다.

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

@@ -10,6 +10,7 @@
 import javax.sql.DataSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import org.springframework.dao.DataAccessException;
 
 public class JdbcTemplate {
 
@@ -23,54 +24,54 @@ public JdbcTemplate(final DataSource dataSource) {
 
     public void execute(final String sql, final Object... objects) {
         try (final Connection conn = dataSource.getConnection();
-             final PreparedStatement pstmt = conn.prepareStatement(sql)
+             final PreparedStatement pstmt = preparedStatementAndSetValue(conn, sql, objects)
         ) {
-            log.debug("query : {}", sql);
-            setValues(pstmt, objects);
             pstmt.executeUpdate();
         } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new RuntimeException(e);
+            throw new DataAccessException(e.getMessage());
         }
     }
 
     public <T> List<T> query(final String sql, final RowMapper<T> rowMapper, final Object... objects) {
         try (final Connection conn = dataSource.getConnection();
-             final PreparedStatement pstmt = conn.prepareStatement(sql)
+             final ResultSet rs = preparedStatementAndSetValue(conn, sql, objects).executeQuery()
         ) {
-            log.debug("query : {}", sql);
-            setValues(pstmt, objects);
-            final ResultSet rs = pstmt.executeQuery();
             final List<T> list = new ArrayList<>();
             while (rs.next()) {
                 list.add(rowMapper.mapRow(rs));
             }
             return list;
         } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new RuntimeException(e);
+            throw new DataAccessException(e.getMessage());
         }
     }
 
     @Nullable
     public <T> T queryForObject(final String sql, final RowMapper<T> rowMapper, final Object... objects) {
         try (final Connection conn = dataSource.getConnection();
-             final PreparedStatement pstmt = conn.prepareStatement(sql)
+             final ResultSet rs = preparedStatementAndSetValue(conn, sql, objects).executeQuery()
         ) {
-            log.debug("query : {}", sql);
-            setValues(pstmt, objects);
-            final ResultSet rs = pstmt.executeQuery();
             if (rs.next()) {
                 return rowMapper.mapRow(rs);
             }
             return null;
         } catch (SQLException e) {
-            log.error(e.getMessage(), e);
-            throw new RuntimeException(e);
+            throw new DataAccessException(e.getMessage());
         }
     }
 
-    private void setValues(final PreparedStatement pstmt, Object... objects) throws SQLException {
+    private PreparedStatement preparedStatementAndSetValue(
+            final Connection conn,
+            final String sql,
+            final Object... objects
+    ) throws SQLException {
+        final PreparedStatement pstmt = conn.prepareStatement(sql);
+        log.debug("query : {}", sql);
+        setValues(pstmt, objects);
+        return pstmt;
+    }
+
+    private void setValues(final PreparedStatement pstmt, final Object... objects) throws SQLException {
         for (int i = 0; i < objects.length; i++) {
             pstmt.setObject(i + 1, objects[i]);
         }

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

@@ -3,6 +3,7 @@
 import java.sql.ResultSet;
 import java.sql.SQLException;
 
+@FunctionalInterface
 public interface RowMapper<T> {
 
     T mapRow(final ResultSet rs) throws SQLException;