摘要：引言在監(jiān)控系統(tǒng)網(wǎng)頁爬蟲審核流程等領(lǐng)域，經(jīng)常需要保存系統(tǒng)在某一時刻的狀態(tài)網(wǎng)頁快照。之后使用另一個命令行訪問本地的端口能夠看到調(diào)試信息應(yīng)該就是安裝成功了下載提供了操作的，是控制的橋梁。

在監(jiān)控系統(tǒng)、網(wǎng)頁爬蟲、審核流程等領(lǐng)域，經(jīng)常需要保存系統(tǒng)在某一時刻的狀態(tài)-網(wǎng)頁快照。實(shí)現(xiàn)網(wǎng)頁快照主要有phantomjs、selenium,但是網(wǎng)上資料都是零碎的，本文主要采用Selenium,詳細(xì)闡述從編碼到部署的整個流程.

    org.seleniumhq.selenium
    selenium-java
    3.11.0

(1) 創(chuàng)建WebDriver

a.手機(jī)設(shè)備

public WebDriver createWebDriver(String device) {
    Map mobileEmulation = new HashMap();
    //設(shè)置設(shè)備,例如:Google Nexus 7/Apple iPhone 6
    //mobileEmulation.put("deviceName", "Google Nexus 7");
    if(StringUtils.isBlank(device))
        device = "iPhone 6";
    mobileEmulation.put("deviceName", device);   //這里是要使用的模擬器名稱，就是瀏覽器中模擬器中的頂部型號
    Map chromeOptions = new HashMap();
    chromeOptions.put("mobileEmulation", mobileEmulation);
    DesiredCapabilities capabilities = DesiredCapabilities.chrome();
    capabilities.setCapability(ChromeOptions.CAPABILITY, chromeOptions);
    WebDriver driver = new ChromeDriver(capabilities);
    Dimension dimension = new Dimension(420, 900);
    driver.manage().window().setSize(dimension);
    return driver;
}

b.PC設(shè)備

public WebDriver createWebDriver(String device) {
    //暫時采用特定分辨率
    ChromeOptions options = new ChromeOptions();
    options.addArguments("window-size=1200,800");
    WebDriver driver = new ChromeDriver(options);
    driver.manage().window();
    return driver;
}

(2) 繪制圖像

    public String execute(String uri, String device) {
        PerfCounter.count("miui_ad_schedule_capture.execute.total", 1L);
        long start = System.currentTimeMillis();
        System.setProperty("webdriver.chrome.driver", "/home/rd/chromedriver");
        //windows: System.setProperty("webdriver.chrome.driver", "src/main/resources/driver/chromedriver.exe");
        WebDriver driver = createWebDriver(device);
        String cdnUrl = "";
        try {
            driver.get(uri);
            cdnUrl = savePage(driver, url, "capture_" + System.currentTimeMillis() + ".png");
        } catch (Exception e) {
            logger.error("capture fail: [{},{}],{} !", uri ,device,e);
        } finally {
            driver.close();
            driver.quit();
        }
        PerfCounter.count("miui_ad_schedule_capture.execute.success", 1L, System.currentTimeMillis() - start);
        return cdnUrl;
    }

    private String savePage(WebDriver driver, String filePath, String fileName) throws IOException, InterruptedException, NoSuchAlgorithmException {
        JavascriptExecutor jsExecutor = (JavascriptExecutor) driver;
        TakesScreenshot takesScreenshot = (TakesScreenshot) driver;
        jsExecutor.executeScript("window.scrollTo(0,0)");
        BufferedImage imageOriginal = new BufferedImage(1, 1, BufferedImage.TYPE_INT_RGB);// 創(chuàng)建全屏截圖
        int lastScroll = -1;
        int currentScroll = 0;
        Thread.sleep(1000);
        while (lastScroll != currentScroll) {
            byte[] bytesScroll = takesScreenshot.getScreenshotAs(OutputType.BYTES);
            BufferedImage imageScroll = ImageIO.read(new ByteArrayInputStream(bytesScroll));
            int screenHeight = imageScroll.getHeight();
            int screenWidth = imageScroll.getWidth();
            System.out.println("scree:" + screenHeight + ":" + screenWidth);

            BufferedImage combined = new BufferedImage(screenWidth, currentScroll + screenHeight, BufferedImage.TYPE_INT_RGB);
            Graphics g = combined.getGraphics();
            g.drawImage(imageOriginal, 0, 0, null);
            g.drawImage(imageScroll, 0, currentScroll, null);
            imageOriginal = combined;

            logger.info("lastScroll:" + lastScroll + "    currentScroll:" + currentScroll + "    screenHeight:" + screenHeight);
            int scrollTo = currentScroll + screenHeight;
            lastScroll = currentScroll;
            jsExecutor.executeScript("window.scrollTo(0," + scrollTo + ")");
            currentScroll = Double.valueOf(jsExecutor.executeScript("return document.documentElement.scrollTop").toString()).intValue();
            System.out.println(screenHeight + ":" + scrollTo);
            if (lastScroll > 5000) {
                break;
            }
            Thread.sleep(1000);
        }

        File path = new File(filePath);
        if (!path.exists() || !path.isDirectory()) {
            path.mkdirs();
        }
        File file = new File(path.getAbsolutePath() + File.separatorChar + fileName);
        ImageIO.write(imageOriginal, "png", file);
        String uploadPath = FileStorageUtils.upload(file.getAbsolutePath(), CHANNEL_ID);
        System.out.println("uploadPath:" + uploadPath);
        if(file.exists()){
            file.delete();
        }
        return uploadPath;
    }

(1) 安裝chrome

sudo apt-get install libxss1 libappindicator1 libindicator7 #install dependency
wget https://dl.google.com/linux/direct/google-chrome-stable_current_amd64.deb
sudo dpkg -i google-chrome*.deb  
sudo apt-get install -f

安裝完成后測試：

google-chrome --headless --remote-debugging-port=9222 https://chromium.org --disable-gpu

這里是使用headless模式進(jìn)行遠(yuǎn)程調(diào)試，ubuntu上大多沒有g(shù)pu，所以--disable-gpu以免報錯。之后使用另一個命令行訪問本地的9222端口：

curl http://localhost:9222

能夠看到調(diào)試信息應(yīng)該就是安裝成功了

(2) 下載chromedriver

chromedriver提供了操作chrome的api，是selenium控制chrome的橋梁。
可以到：https://sites.google.com/a/ch...。
下載并解壓：

wget https://chromedriver.storage.googleapis.com/2.37/chromedriver_linux64.zip
unzip chromedriver_linux64.zip

Chrome與WebDriver的版本對應(yīng)關(guān)系：

(3) 安裝Xfvb

如果不安裝Xfvb,java -jar xxx.jar 將報一下錯誤：

Starting ChromeDriver 2.30.477691 (6ee44a7247c639c0703f291d320bdf05c1531b57) on port 14103
Only local connections are allowed.
Exception in thread "main" org.openqa.selenium.WebDriverException: unknown error: Chrome failed to start: exited abnormally
  (Driver info: chromedriver=2.30.477691 (6ee44a7247c639c0703f291d320bdf05c1531b57),platform=Linux 4.9.15-x86_64-linode81 x86_64) (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 60.13 seconds
Build info: version: "unknown", revision: "unknown", time: "unknown"
System info: host: "localhost", ip: "127.0.0.1", os.name: "Linux", os.arch: "amd64", os.version: "4.9.15-x86_64-linode81", java.version: "1.8.0_131"
Driver info: driver.version: ChromeDriver
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    ...

安裝方式：
a.安裝Xvfb

sudo apt install Xvfb

b.啟動Xvfb服務(wù)

Xvfb -ac :7 -screen 0 1280x1024x8 &

c.連接服務(wù)7

export DISPLAY=:7

關(guān)于Xvfb的具體應(yīng)用請參考:https://www.x.org/archive/X11R7.6/doc/man/man1/Xvfb.1.xhtml

參考鏈接:
https://blog.csdn.net/codebat...
https://jiayi.space/post/zai-...

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