public void varify() {
        try {
            HashMap<String, Integer> maps = new HashMap<String, Integer>();
            int datanum = 0;
            for (int i = 1; i <= numbersOfThreads; i++) {
                File f = new File(outputPath + "/id" + i);
                if (f.exists()) {

                    BufferedReader br = new BufferedReader(new FileReader(f));
                    String line = null;

                    while ((line = br.readLine()) != null) {
                        int counter = 1;
                        datanum++;
                        if (maps.containsKey(line)) {
                            counter = maps.get(line) + 1;
                        }
                        maps.put(line, counter);
                    }

                    br.close();
                }

            }

            System.out.println("=== Result ===");
            System.out.println("total numbers of output: \t\t"+datanum);

            int counter = 0;
            for (String key : maps.keySet()) {
                if (maps.get(key) >= 2) {
                    counter++;
                    if (isOutputCollision()) {
                        System.out.println(key + ": " + maps.get(key));
                    }
                }
            }

            System.out.println("numbers of duplication: \t" + counter);
            System.out.println("duplication ratio: \t"+((counter/(float)datanum)*100f)+"%");

        } catch (Exception err) {
            err.printStackTrace();
        }
    }