javaIO文件複製對比

測試字節流和字符流的讀寫速度

/**
 * copy file
 *
 * @author dxy
 * @date 2020/1/9 13:05
 */
public class DemoCopyIo {
//    private static final String SRC = "C:\\Users\\Administrator\\Desktop\\RAF.txt";
    private static final String SRC = "C:\\Users\\Administrator\\Desktop\\layui-master.zip";
//    private static final String SRC_TO_FILE1 = "C:\\Users\\Administrator\\Desktop\\RAFCOPY1.txt";
//    private static final String SRC_TO_FILE2 = "C:\\Users\\Administrator\\Desktop\\RAFCOPY2.txt";
//    private static final String SRC_TO_FILE3 = "C:\\Users\\Administrator\\Desktop\\RAFCOPY3.txt";
    private static final String SRC_TO_FILE1 = "C:\\Users\\Administrator\\Desktop\\RAFCOPY1.zip";
    private static final String SRC_TO_FILE2 = "C:\\Users\\Administrator\\Desktop\\RAFCOPY2.zip";
    private static final String SRC_TO_FILE3 = "C:\\Users\\Administrator\\Desktop\\RAFCOPY3.zip";

    public static void main(String[] args) throws IOException {

        System.out.println("開始測試！");
        // BufferedReader字符流複製文件
        bufferedReader();

        // 字節流複製文件
        inputStream();

        // 字節流複製文件（加入緩衝）
        BufferedInputStream();
    }

    /**
     * 爲字符流專門打造的(適合字符的操作) 讀、寫
     *
     * @throws IOException IO
     */
    private static void bufferedReader() throws IOException {
        long start = System.currentTimeMillis();
        BufferedReader bufferedReader = new BufferedReader(
                new InputStreamReader(new FileInputStream(SRC), StandardCharsets.UTF_8));
        PrintWriter printWriter = new PrintWriter(
                new OutputStreamWriter(new FileOutputStream(SRC_TO_FILE1), StandardCharsets.UTF_8));
        try {
            while (true) {
                String s = bufferedReader.readLine();
                if (s != null) {
                    printWriter.println(s);
//                    System.out.println(s);
                } else {
                    break;
                }
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        bufferedReader.close();
        printWriter.close();
        long end = System.currentTimeMillis();
        System.out.println("bufferedReader耗時" + (end - start));
    }

    /**
     * 字節流讀、寫文件（通用型的）
     *
     * @throws IOException IO
     */
    private static void inputStream() throws IOException {
        long start = System.currentTimeMillis();
        InputStream inputStream = new FileInputStream(SRC);
        OutputStream outputStream = new FileOutputStream(SRC_TO_FILE2);
        byte[] bytes = new byte[1024];
        while (true) {
            int read = inputStream.read(bytes);
            if (read != -1) {
                outputStream.write(bytes);
//                System.out.println(new String(bytes, 0, read));
            } else {
                break;
            }
        }
        inputStream.close();
        outputStream.close();
        long end = System.currentTimeMillis();
        System.out.println("inputStream耗時" + (end - start));

    }

    /**
     * 字節流讀、寫文件（通用型的）+加上緩衝
     *
     * @throws IOException IO
     */
    private static void BufferedInputStream() throws IOException {
        long start = System.currentTimeMillis();
        InputStream inputStream = new FileInputStream(SRC);
        OutputStream outputStream = new FileOutputStream(SRC_TO_FILE3);
        BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
        BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);
        byte[] bytes = new byte[1024];
        while (true) {
            int read = bufferedInputStream.read(bytes);
            if (read != -1) {
                bufferedOutputStream.write(bytes);
//                System.out.println(new String(bytes, 0, read));
            } else {
                break;
            }
        }
        inputStream.close();
        outputStream.close();
        long end = System.currentTimeMillis();
        System.out.println("BufferedInputStream耗時" + (end - start));
    }


}