public static HashMap<String,String> getChildrenFolderUsage(File file){
            if(!file.isDirectory()){
                return null;
            }
            File[] children = file.listFiles();
            float sum = getDirSize(file)/1024;
            float sum20Percent = sum*0.08f;
            if(children!=null && children.length>0){
                HashMap<String ,String> map = new HashMap<>();
                for(int i=0;i<children.length;i++){
                    if(children[i].isDirectory()){
                        float dirSize = getDirSize(children[i])/1024.00f;
                        System.out.println("getChildrenFolderUsage folder name "+children[i].getName()+"="+dirSize+",sum20Percent="+sum20Percent+",sum="+sum);
                        if(dirSize>sum20Percent){
                             map.put(children[i].getName(), String.valueOf(dirSize));
                        }
                    }else{
                        if(map.get("other")!=null){
                            float otherFileSize =Float.parseFloat(map.get("other"));
                            map.put("other",String.valueOf((otherFileSize+children[i].length())/1024.00));
                        }else{
                            map.put("other",String.valueOf(children[i].length()/1024.00));
                        }
                    }
                }
                return map;
            }
            return null;
        }