Java 如何在GoogleWebToolkit（GWT）中从JSNI调用接口（实例化）

我有一个实现接口的类，我需要从GWT中的JSNI调用该方法

接口：

类别：

---

您可以这样做：

public static native void grouping(HeaderFormatter hf) /*-{
   var value = // some String 
   var result = hf.@path.to.interface.HeaderFormatter::format(Ljava/lang/String)(value);
}-*/;

 public GWTGrouping implements HeaderFormatter {

    public String format(String value){
      return "<span><i class='fa fa-stop'></i></span>";
    }
    public void performGrouping(){
        if(isgroup){
          grouping();
        }  
    }

    public static native void grouping() /*-{
    //dont want to pass whole class to this method (this)
    //Need to access format(String value) Method which will return some logic
    //How to access that method here by passing interface not whole class
    }-*/;

}

public static native void grouping(HeaderFormatter hf) /*-{
   var value = // some String 
   var result = hf.@path.to.interface.HeaderFormatter::format(Ljava/lang/String)(value);
}-*/;