import java.io.File;

import java.io.IOException;

import org.apache.commons.io.FileUtils;

import org.openqa.selenium.OutputType;

import org.openqa.selenium.TakesScreenshot;

import org.openqa.selenium.WebDriver;

import org.openqa.selenium.firefox.FirefoxDriver;

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

        //定义一个前缀文件夹

        String prefix="D:/test";

        WebDriver dr = new FirefoxDriver();

        String url = "http://www.cnblogs.com/";

        dr.get(url);

        Thread.sleep(3000);
        //截图

        File screenShotFile =((TakesScreenshot)dr).getScreenshotAs(OutputType.FILE);
        //文件命名

        File file = new File(prefix+File.separator+System.currentTimeMillis()+".png");

        File tempDir = new File(prefix);
        //判断根目录文件夹是否存在

        if  (!tempDir .exists()  || !tempDir .isDirectory()){

            tempDir .mkdir();

        }

        else{

            int i=1;

            while(file.exists()){
                //命名重复就后缀加_1

                file = new File(prefix+File.separator+System.currentTimeMillis()+"_"+i+".png");

            }

        }
        //输出

        FileUtils.copyFile(screenShotFile, file);

    }