optimized for mysql

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

@@ -0,0 +1,20 @@
+package com.alibaba.druid.util;
+
+import java.sql.Connection;
+import java.sql.SQLException;
+
+
+public class MySqlUtils {
+    public static com.mysql.jdbc.Connection unwrap(Connection conn) throws SQLException {
+        if (conn instanceof com.mysql.jdbc.Connection) {
+            return (com.mysql.jdbc.Connection) conn;
+        }
+
+        return conn.unwrap(com.mysql.jdbc.Connection.class);
+    }
+    
+    public static void ping(Connection conn) throws SQLException {
+        com.mysql.jdbc.Connection mysqlConn = unwrap(conn);
+        mysqlConn.ping();
+    }
+}