比较java中两个文本文件的时间消耗？

Question

我有两个不同的大文本文件z和xz，每个大小为MB。将z文本文件内容与xz文本文件内容进行比较（如果有任何内容匹配）将其写入新的文本文件输出。

验证需要花费大量时间，而且不会写入输出文件。

如何写入输出文件？

public class CompareTwo {
    static int count1 = 0;
    static int count2 = 0;

    static String arrayLines1[] = new String[countLines("C:/Users/THAKUR SANTHOSHI/Desktop/z.txt")];
    static String arrayLines2[] = new String[countLines("C:/Users/THAKUR SANTHOSHI/Desktop/xz.txt")];

    public static void main(String args[]) {
        findDifference("C:/Users/THAKUR SANTHOSHI/Desktop/z.txt", "C:/Users/THAKUR SANTHOSHI/Desktop/xz.txt");
        try {
            displayRecords();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }

    public static int countLines(String File) {

        int lineCount = 0;
        BufferedReader br = null;
        try {
            br = new BufferedReader(new FileReader(File));
            while ((br.readLine()) != null) {
                lineCount++;
            }

        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            if (br != null) {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return lineCount;
    }

    public static void findDifference(String File1, String File2) {
        String contents1 = null;
        String contents2 = null;
        BufferedReader buf1 = null;
        BufferedReader buf2 = null;
        try {
            FileReader file1 = new FileReader(File1);
            FileReader file2 = new FileReader(File2);
            buf1 = new BufferedReader(file1);
            buf2 = new BufferedReader(file2);

            while ((contents1 = buf1.readLine()) != null) {
                arrayLines1[count1] = contents1;
                count1++;
            }

            while ((contents2 = buf2.readLine()) != null) {
                arrayLines2[count2] = contents2;
                count2++;
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (buf1 != null) {
                try {
                    buf1.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            if (buf2 != null) {
                try {
                    buf2.close();
                } catch (IOException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
        }
    }

    public static void displayRecords() throws IOException {
        // true = append file
        File file = new File("D:/out.txt");
        FileWriter fileWritter = new FileWriter(file.getName(), true);
        BufferedWriter bufferWritter = new BufferedWriter(fileWritter);
        for (int i = 0; i < arrayLines1.length; i++) {
            String a = arrayLines1[i];
            for (int j = 0; j < arrayLines2.length; j++) {
                String b = arrayLines2[j];
                boolean result = a.equals(b);
                if (result == true) {
                    if (a != null && !a.trim().isEmpty()) {
                        bufferWritter.write(a);
                        bufferWritter.flush();
                        System.out.println(a + " Copied.");
                    }
                }
            }
        }
        bufferWritter.close();
    }
}