Question

我的C：驱动器中有一个名为abcd.log的日志文件，我正在通过java程序读取它，我想测量程序完全读取日志文件花了多少时间请告知如何实现这一点.. !!

public class Readdemo {



    public static void main(String[] args) {

        File file = new File("C://abcd.log");
        FileInputStream fis = null;

        try {
            fis = new FileInputStream(file);

            System.out.println("Total file size to read (in bytes) : "
                    + fis.available());

            int content;
            while ((content = fis.read()) != -1) {
                // convert to char and display it
                System.out.print((char) content);
            }

        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (fis != null)
                    fis.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }
    }
}

我想出了这个......

public class BufferedRedeem {


    public static void main(String[] args) {

        BufferedReader br = null;
        long startTime = System.currentTimeMillis();

        try {

            String sCurrentLine;

            br = new BufferedReader(new FileReader("C://abcd.log"));

            while ((sCurrentLine = br.readLine()) != null) {
                System.out.println(sCurrentLine);
            }
            long elapsedTime = System.currentTimeMillis() - startTime;

            System.out.println("Total execution time taken in millis: "
                    + elapsedTime);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            try {
                if (br != null)br.close();
            } catch (IOException ex) {
                ex.printStackTrace();
            }
        }

    }

}

Answer 1

只需使用System.currentTimeMillis()记录前/后时间（以毫秒为单位）。

System.nanoTime()是另一种选择，但值得阅读this answer以了解差异和用法。

关于计算读取文件所花费的总时间

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