support spring Jdbc4NativeJdbcExtractor

src/main/java/com/alibaba/druid/util/OracleUtils.java

@@ -88,6 +88,7 @@ public class OracleUtils {
         oracleConn.setStatementCacheSize(size);
     }
 
+    @SuppressWarnings("deprecation")
     public static int pingDatabase(Connection conn) throws SQLException {
         OracleConnection oracleConn = unwrap(conn);
         return oracleConn.pingDatabase(1000);