diff --git a/src/main/java/com/alibaba/druid/pool/vendor/OracleValidConnectionChecker.java b/src/main/java/com/alibaba/druid/pool/vendor/OracleValidConnectionChecker.java
index b52ff4c113..3d3a82711c 100644
--- a/src/main/java/com/alibaba/druid/pool/vendor/OracleValidConnectionChecker.java
+++ b/src/main/java/com/alibaba/druid/pool/vendor/OracleValidConnectionChecker.java
@@ -36,11 +36,9 @@ public class OracleValidConnectionChecker implements ValidConnectionChecker, Ser
 
     private static final Log  LOG              = LogFactory.getLog(OracleValidConnectionChecker.class);
 
-    private Class<?>          clazz;
-    private Method            ping;
-
-    // The timeout (apparently the timeout is ignored?)
-    private static Object[]   params           = new Object[] { new Integer(5000) };
+    private final Class<?>          clazz;
+    private final Method            ping;
+    private final static Object[]   params           = new Object[] { new Integer(5000) };
 
     public OracleValidConnectionChecker(){
         try {