Grid clearAndLoad 2byte language problem

1 years ago created a project with the 3.6 version.
in the URL in the dhtmlxgrid.clearAndLoad 2byte character (korean language) enters look garbled on the server.
The Tomcat server.xml to use that URIEncoding = “UTF-8”.
In the 4.0 version, post method fixed it, but
Changing the dhtmlx to 4.0, so we need to change too much code.
In reality, we can not do that.
Related captured images was attached.

What should we do?