we tried to write rules in chinese like follows

rule "Reorder alert when item expires"
salience 10
when
    $item : ImsItemRecords ()
then
    if ( ! (new Date()).before ($item.getExpireDate()))
    {
      SysAlert alert = new SysAlert("过期 - " + $item.getItemName(), "补充库存", "很高", "新到", new Date(), null);
      SysRecommendation recommendation1 = new SysRecommendation (alert, "补充库存", "购买" + $item.getAmount() + $item.getUnit() + $item.getItemName(), "仓库管理人员", "立即");
      ...

HashSet recommendations = new HashSet();
recommendations.add(recommendation1);

      ...
      alert.setSysRecommendations(recommendations);
      insert (alert);
    }
end

The rule was executed, but the result is unexpected. some of above chinese characters (for example, "新到") are good; some of above chinese characters become ??? after rule evaluation.

any tips how to fix this.