public void screenShot() throws IOException, InterruptedException
{
    File scr = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
    File dest = new File("filPath/1.png");
    FileUtils.copyFile(scr, dest);
}

public void screenShot() throws IOException, InterruptedException
{
    File scr=((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);

    File dest= new File("filPath/screenshot_"+timestamp()+".png");
    FileUtils.copyFile(scr, dest);
}

public string timestamp() {
    return new SimpleDateFormat("yyyy-MM-dd HH-mm-ss").format(new Date());
}

public void screenShot() throws IOException, InterruptedException {
    File scr = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
    String filename =  new SimpleDateFormat("yyyyMMddhhmmss'.txt'").format(new Date());
    File dest = new File("filePath/" + filename);
    FileUtils.copyFile(scr, dest);
}

public void screenShot(string filename) throws IOException, InterruptedException {
    File scr = ((TakesScreenshot)driver).getScreenshotAs(OutputType.FILE);
    File dest = new File("filePath/" + filename);
    FileUtils.copyFile(scr, dest);
}