String.length爆空指针异常解决方法_.length()爆空指针怎么解决-优快云博客

本文链接：https://blog.youkuaiyun.com/weixin_42664511/article/details/90375143

博客指出若数据库中没有 picture 和 video 图片及视频，if()语句会出现空指针异常。解决办法是添加 picture!=null && 进行判断，避免报错。

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for (int i = 0; i < data.size(); i++) {
           //取出查询的每一条数据 list 中每一条都是hashmap
           HashMap<String, Object> hashMap = (HashMap<String, Object>) data.get(i);
           String picture = (String) hashMap.get("picture");
           System.out.println(picture+"----------------------");
           List<String> pictureC = new ArrayList<>();
           if (picture.length()>0) {
               String[] split = picture.split(",");
               for (int t = 0; t < split.length; t++) {
                   pictureC.add(split[t]);
               }
           }
           String video = (String) hashMap.get("video");
           List<String> videoC = new ArrayList<>();
           if (video.length()>0) {
               String[] split = video.split(",");
               for (int t = 0; t < split.length; t++) {
                   videoC.add(split[t]);
               }
           }

如果数据库没有 picture， video 图片和视频的话，上面if（）会报错，空指针异常
给他俩加上 picture!=null && 就可以,判断一下

 for (int i = 0; i < data.size(); i++) {
            //取出查询的每一条数据 list 中每一条都是hashmap
            HashMap<String, Object> hashMap = (HashMap<String, Object>) data.get(i);
            String picture = (String) hashMap.get("picture");
            System.out.println(picture+"----------------------");
            List<String> pictureC = new ArrayList<>();
            if (picture!=null &&picture.length()>0) {
                String[] split = picture.split(",");
                for (int t = 0; t < split.length; t++) {
                    pictureC.add(split[t]);
                }
            }
            String video = (String) hashMap.get("video");
            List<String> videoC = new ArrayList<>();
            if (picture!=null &&video.length()>0) {
                String[] split = video.split(",");
                for (int t = 0; t < split.length; t++) {
                    videoC.add(split[t]);
                }
            }