PropertyEditorSupport方法未执行

Question

我想使用spring mvc convert json到一个像

这样的对象

 @RequestMapping(value = "searchPolygonArea/", method = RequestMethod.GET,params = {"region != null"})
    public @ResponseBody ResultBean <List <Spot>> searchPolygonArea(@ModelAttribute (value="regionModel") Region regions,@RequestParam(value="region") Region region){
        return new ResultBean <List<Spot>> ();
    }

    @InitBinder(value="regionModel")
    public void initBinder(WebDataBinder dataBinder,@RequestParam(value="region") final String regionParams){//,
        dataBinder.registerCustomEditor (Region.class, new PropertyEditorSupport (){
            Region value ;
            @Override
            public Object getValue () {
                return new Region ();
            }
            @Override
            public void setAsText (String text) throws IllegalArgumentException {
                System.out.println (text);
                try {
                    value = JSONUtils.json2Obj (text, Region.class);
                }
                catch (Exception e) {
                    e.printStackTrace();
                }
            }


});
    }

但是setAsText和getValue没有执行，我不知道为什么。