【JAVA】文件各行打乱

给定一个文件，把文件 里的各行打乱，并验证其正确性，时间紧迫，随手写写

        String path = "/Users/guangyi.zgy/Desktop/scene_2khas_8kno_query_1W.csv";
        List<String>  newList=new ArrayList<String>();
        //打开文件
        File file = new File(path);
            try {
                InputStream instream = new FileInputStream(file);
                if (instream != null)
                {
                    InputStreamReader inputreader = new InputStreamReader(instream);
                    BufferedReader buffreader = new BufferedReader(inputreader);
                    String line;
                    //分行读取
                    int j = 0;
                    while (( line = buffreader.readLine()) != null) {
                        newList.add(line);
                    }
                    instream.close();

                    String[] newA = new String[newList.size()];
                    for (String str : newList) {
                        Random random = new Random();
                        int a = random.nextInt(newList.size());
                        if (newA[a] == null) {
                            newA[a] =  str;
                        } else {
                            for (int i = 0; i < newA.length; i++) {
                                if (newA[i] == null) {
                                    newA[i] = str;
                                    break;
                                }
                            }
                        }
                    }
                    String pathNew = "/Users/guangyi.zgy/Desktop/NEW_scene_2khas_8kno_query_1W.csv";
                    File fileNew = new File(pathNew);
                    fileNew.createNewFile();

                    OutputStream outputStream = new FileOutputStream(fileNew);
                    BufferedWriter bf = new BufferedWriter(new OutputStreamWriter(outputStream));

                    boolean firstLine = true;
                    for (String str : newA) {
                        if (firstLine) {
                            bf.write(str);
                            firstLine = false;
                            continue;
                        }
                        if (str != null) {
                            bf.write("
" + str);
                        } else {
                            System.out.println("有空行出现");
                        }
                    }
                    bf.close();

                    for (String str : newA) {
                        int count = 0;
                        for (String str1 : newA) {
                            if (StringUtils.equals(str1.trim(), str.trim())) {
                                count ++;
                            }
                        }
                        if (count > 1) {
                            System.out.println("有多个相同字符");
                        }
                    }
                }
            }
            catch (java.io.FileNotFoundException e)
            {
            }
            catch (IOException e)
            {
            }