接口问题实现

自定义工具类含有接口

public void setOnBack(String s,onBack onBack)
{
   this.str=s;
   this.onback=onBack;
}
public void helep() throws JSONException {
   FoodDate foodDate=new FoodDate();
   JSONObject jsonObject=new JSONObject(str);
 foodDate.setFoodname( jsonObject.getString("name"));
   foodDate.setInfo(jsonObject.getString("description"));
   foodDate.settPrice("tPrice");
   foodDate.setOriginalprice(jsonObject.getString("originalprice"));
   foodDate.setPath(jsonObject.getString("img"));
   foodDate.setPrice(jsonObject.getString("price"));
   onback.inFodate(foodDate);//接口

}

fragment里的Thread接口实现

dateHelp.setOnBack(s, new onBack() {
   @Override
   public void inFodate(FoodDate food) {
       Message mes=Message.obtain();
       mes.arg1=0;
       mes.obj=food;

       handle.sendMessage(mes);
   }
});
dateHelp.helep();

无法实现这个接口的方法？？？？？？？？？？？？？？？
handle=  new Handler(){
     @Override
     public void handleMessage(Message msg) {
           super.handleMessage(msg);
           FOOD_DATE= (FoodDate) msg.obj;
      textview.setText(FOOD_DATE.getFoodname());