WebMagic抓取 table分页数据， table分页时，URL不变

动态页面爬虫前的准备：https://www.cnblogs.com/maohuidong/p/18517953

一：java添加maven依赖：

<dependency>
    <groupId>us.codecraft</groupId>
    <artifactId>webmagic-core</artifactId>
    <version>0.7.4</version>
</dependency>
<dependency>
    <groupId>us.codecraft</groupId>
    <artifactId>webmagic-extension</artifactId>
    <version>0.7.4</version>
</dependency>
<!--selenium依赖-->
<dependency>
    <groupId>org.seleniumhq.selenium</groupId>
    <artifactId>selenium-java</artifactId>
    <version>3.141.59</version>
</dependency>

二：重写PageProcessor：

import java.util.List;
import java.util.Set;

import org.openqa.selenium.By;
import org.openqa.selenium.Cookie;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;

import org.openqa.selenium.chrome.ChromeOptions;
import org.openqa.selenium.remote.RemoteWebDriver;
import us.codecraft.webmagic.Page;
import us.codecraft.webmagic.Site;
import us.codecraft.webmagic.Spider;
import us.codecraft.webmagic.pipeline.JsonFilePipeline;
import us.codecraft.webmagic.processor.PageProcessor;

/**
 * 准备抓取这个页面：http://yapi.rongyi.so/project/317/interface/api
 * 但是这个页面需要登录后才能访问，登录页面为：http://yapi.rongyi.so/login
 * 登录后抓取的页面有 分页， 分页的特点是地址不变，所以从第二页开始，无法通过webMagic抓取第二页的内容
 * 只能通过Selenium来点击下一页的操作，然后再解析页面。
 */
public class YapiPageProcessor implements  PageProcessor {

    private Site site = Site.me().setRetryTimes(3).setSleepTime(0).setTimeOut(3000);

    //用来存储cookie信息
    private Set<Cookie> cookies;

    private RemoteWebDriver driver;

    public YapiPageProcessor(){
        System.setProperty("webdriver.chrome.driver","E:\\chromedriver-win64\\chromedriver-win64\\chromedriver.exe");

        //创建浏览器参数对象
        ChromeOptions chromeOptions = new ChromeOptions();
        // 设置为 无界面浏览器 模式,若是不想看到浏览器打开，就可以配置此项

        //解决 403 出错问题
        chromeOptions.addArguments("--remote-allow-origins=*");
        // chromeOptions.addArguments("--headless");
        chromeOptions.addArguments("--window-size=1440,1080");// 设置浏览器窗口打开大小

        RemoteWebDriver driver = new ChromeDriver(chromeOptions);
        this.driver = driver;
    }


    @Override
    public void process(Page page) {
        // 取所有的key 和对应的所有的value
        List<String> keys = page.getHtml().xpath("//tbody[@class='ant-table-tbody']/tr/td/a/span/text()").all();
        List<String> values = page.getHtml().xpath("//tbody[@class='ant-table-tbody']/tr/td/div/span[3]/text()").all();
        //获取用户的id
        for (int i = 0;i < keys.size();i++) {
            page.putField(keys.get(i),values.get(i));
        }

        while (driver.findElements(By.xpath("//li[@title='下一页' and @aria-disabled='false']")).size() > 0){
            // 点击下一页
            driver.findElement(By.xpath("//li[@title='下一页' and @aria-disabled='false']")).click();

            // 等待2S
            try {
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }

            List<WebElement> elements = driver.findElements(By.xpath("//tbody[@class='ant-table-tbody']/tr"));
            for (int ii = 1;ii <= elements.size();ii++) {
                WebElement key = driver.findElement(By.xpath("//tbody[@class='ant-table-tbody']/tr[" + ii + "]/td/a/span"));
                WebElement value = driver.findElement(By.xpath("//tbody[@class='ant-table-tbody']/tr[" + ii + "]/td/div/span[3]"));
                page.putField(key.getText(),value.getText());
            }
        }
    }

    //使用 selenium 来模拟用户的登录获取cookie信息
    public void login(String loginUrl,String userName,String password)
    {
        driver.get(loginUrl);

        driver.findElement(By.id("email")).clear();

        //在******中填你的用户名
        driver.findElement(By.id("email")).sendKeys(userName);

        driver.findElement(By.id("password")).clear();
        //在*******填你密码
        driver.findElement(By.id("password")).sendKeys(password);

        //模拟点击登录按钮
        driver.findElement(By.xpath("//button[@type='submit']")).click();

        //获取cookie信息
        cookies = driver.manage().getCookies();
       // driver.close();
    }


    @Override
    public Site getSite() {

        //将获取到的cookie信息添加到webmagic中
        for (Cookie cookie : cookies) {
            site.addCookie(cookie.getName().toString(),cookie.getValue().toString());
        }

        return site.addHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.1 (KHTML, like Gecko) Chrome/22.0.1207.1 Safari/537.1");
    }

    public static void main(String[] args){

        YapiPageProcessor pageProcessor = new YapiPageProcessor();

        //调用selenium，进行模拟登录
        pageProcessor.login("http://yapi.rongyi.so/login","xxx","xxx");
        Spider.create(pageProcessor)
                .addUrl("http://yapi.rongyi.so/project/317/interface/api")
                .setDownloader(new MyDownloader(pageProcessor.driver))//可选择使用自定义的
                // 输出到D盘webmagic文件夹
                .addPipeline(new JsonFilePipeline("D:\\webmagic1\\"))
                //开启1个线程抓取
                .thread(1)
                //启动爬虫
                .run();
        System.out.println("爬取结束");
    }
}

三：重写Downloader：

import org.openqa.selenium.WebDriver;
import org.openqa.selenium.chrome.ChromeDriver;
import org.openqa.selenium.chrome.ChromeOptions;
import org.openqa.selenium.remote.RemoteWebDriver;
import us.codecraft.webmagic.downloader.Downloader;
import us.codecraft.webmagic.*;
import us.codecraft.webmagic.selector.PlainText;
import org.openqa.selenium.Cookie;
import java.util.Map;
public class MyDownloader implements Downloader {
    //声明驱动
    private RemoteWebDriver driver;

    public MyDownloader(RemoteWebDriver driver) {
        this.driver = driver;
    }

    /**
     * 由于selenium的默认域名为data;因此第一次必须跳转到登录页，才能加入对应域名
     * @param request Request
     */
    @Override
    public Page download(Request request, Task task) {
        try {
            driver.get(request.getUrl());//第一次打开url，跳转到登录页
            Thread.sleep(3000);//等待打开浏览器
            //获取从process返回的site携带的cookies，填充后第二次打开url
            Site site = task.getSite();
            if (site.getCookies() != null) {
                for (Map.Entry<String, String> cookieEntry : site.getCookies()
                        .entrySet()) {
                    Cookie cookie = new Cookie(cookieEntry.getKey(),
                            cookieEntry.getValue());
                    driver.manage().addCookie(cookie);
                }
                //添加对应domain的cookie后，第二次打开url
                driver.get(request.getUrl());
            }
            Thread.sleep(2000);
            driver.executeScript("window.scrollTo(0, document.body.scrollHeight - 1000)");//需要滚动到页面的底部,获取完整的数据
            Thread.sleep(2000);//等待滚动完成
            //获取页面，打包成Page对象，传给PageProcessor 实现类
            Page page = createPage(request.getUrl(), driver.getPageSource());
            //driver.close();//看需要是否关闭浏览器
            return page;
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    public void setThread(int threadNum) {

    }

    //构建page返回对象
    private Page createPage(String url, String content) {
        Page page = new Page();
        page.setRawText(content);
        page.setUrl(new PlainText(url));
        page.setRequest(new Request(url));
        page.setDownloadSuccess(true);
        return page;
    }