map 重复添加会被覆盖

首先最开始我的代码 ：

@RequestMapping("/index")@ResponseBodypublic Object index() throws Exception{    PageData pd=this.getPageData();    Map<String,Object> map=new HashMap<String,Object>();    Map<String,Object> data=new HashMap<String,Object>();    //List<PageData> goodsList=new ArrayList<PageData>();    List<PageData> banner=indexService.findBanner(pd);    List<PageData> channel= indexService.findchannel(pd);    List<PageData> newGoodsList= goodsService.findnewgoods(pd);    List<PageData> hotGoodsList= goodsService.findhotgoods(pd);    List<PageData> brandList= goodsService.findbrand(pd);    List<PageData> topicList= topicService.findtopic(pd);    List<PageData> categoryList=  categoryService.findCategory(pd);    for(int i=0;i<categoryList.size();i++){       long id= (Long) categoryList.get(i).get("id");       pd.put("id", id);        List<PageData> goodsList=  goodsService.findgoodsbyCategory(pd);        //goodsList.addAll(goods);       data.put("goodsList",goodsList);    }    //data.put("goodsList",goodsList);    data.put("categoryList",categoryList);    data.put("topicList",topicList);    data.put("brandList",brandList);    data.put("banner",banner);    data.put("channel", channel);    data.put("newGoodsList",newGoodsList);    data.put("hotGoodsList",hotGoodsList);map.put("data", data);map.put("errno", 0);return map;}

修改之后：

@RequestMapping("/index")@ResponseBodypublic Object index() throws Exception{    PageData pd=this.getPageData();    Map<String,Object> map=new HashMap<String,Object>();    Map<String,Object> data=new HashMap<String,Object>();    List<PageData> goodsList=new ArrayList<PageData>();    List<PageData> banner=indexService.findBanner(pd);    List<PageData> channel= indexService.findchannel(pd);    List<PageData> newGoodsList= goodsService.findnewgoods(pd);    List<PageData> hotGoodsList= goodsService.findhotgoods(pd);    List<PageData> brandList= goodsService.findbrand(pd);    List<PageData> topicList= topicService.findtopic(pd);    List<PageData> categoryList=  categoryService.findCategory(pd);    for(int i=0;i<categoryList.size();i++){       long id= (Long) categoryList.get(i).get("id");       pd.put("id", id);        List<PageData> goods=  goodsService.findgoodsbyCategory(pd);       goodsList.addAll(goods);    }    data.put("goodsList",goodsList);    data.put("categoryList",categoryList);    data.put("topicList",topicList);    data.put("brandList",brandList);    data.put("banner",banner);    data.put("channel", channel);    data.put("newGoodsList",newGoodsList);    data.put("hotGoodsList",hotGoodsList);map.put("data", data);map.put("errno", 0);return map;}

这样添加的数据就不会被覆盖了