iframe傳參中文亂碼問題

1.jsp頁面

var paramname=encodeURI(encodeURI("中文參數"));
url="${dynamic}/cn/app/controller_add?name="+paramname;
document.getElementById("iframeid").src=url;

2.java後臺

String paramname=request.getParameter("paramname");
try {
    paramname=java.net.URLDecoder.decode(paramname,"utf-8");
}catch (UnsupportedEncodingException e) {
    e.printStackTrace();
}