Question

我正在使用硒库进行测试。但是下面的代码给了我类强制转换异常。我已经用谷歌搜索了这个异常，但是没有得到解决方案。我对Https连接和http连接感到困惑。帮助我解决此异常。谢谢

import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import org.openqa.selenium.By;
import org.openqa.selenium.WebDriver;
import org.openqa.selenium.WebElement;
import org.openqa.selenium.chrome.ChromeDriver;
import sun.net.www.protocol.http.HttpURLConnection;


public class TestMakeMySushi {

  private static final String HttpURLConnection = null;

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

    System.setProperty("webdriver.chrome.driver", "C:\\Users\\Dev-24\\Downloads\\chromedriver.exe");
    WebDriver driver = new ChromeDriver();
    driver.manage().window().maximize();
    driver.manage().deleteAllCookies();
    driver.manage().timeouts().pageLoadTimeout(30, TimeUnit.SECONDS);
    driver.manage().timeouts().implicitlyWait(40, TimeUnit.SECONDS);
    driver.get("https://www.makemysushi.com/404?");

    List<WebElement> linklist = driver.findElements(By.tagName("a"));
    linklist.addAll(driver.findElements(By.tagName("img")));
    System.out.println("size of all link and images list" + linklist.size());
    List<WebElement> activelist = new ArrayList<WebElement>();

    for (int i = 0; i < linklist.size(); i++) {
        System.out.println(linklist.get(i).getAttribute("href"));
        if (linklist.get(i).getAttribute("href") != null && (!linklist.get(i).getAttribute("href").contains("javascript"))) {
            activelist.add(linklist.get(i));
        }
    }


    System.out.println("size of activelink list" + activelist.size());


    for (int j = 0; j < activelist.size(); j++) {

        HttpURLConnection connection = (HttpURLConnection) new URL(activelist.get(j).getAttribute("href")).openConnection();
        connection.connect();
        String response = connection.getResponseMessage();
        connection.disconnect();
        System.out.println(activelist.get(j).getAttribute("href") + "----" + response);
    }
}
}

我面临的异常

Exception in thread "main" java.lang.ClassCastException:   sun.net.www.protocol.https.HttpsURLConnectionImpl cannot be cast to sun.net.www.protocol.http.HttpURLConnection
at TestMakeMySushi.main(TestMakeMySushi.java:76)
C:\Users\Dev-24\AppData\Local\NetBeans\Cache\8.1\executor-snippets\run.xml:53: Java returned: 1

Answer 1

将HttpURLConnection类的导入语句从import sun.net.www.protocol.http.HttpURLConnection;更改为import java.net.HttpURLConnection;。

您不应该在应用程序代码中使用sun包和类。它们是JVM内部的。

Answer 2

@KarolDowbecki的分析方向正确。

而不是sun.net.www.protocol.http.HttpURLConnection; HttpURLConnection 应该通过以下方式解决：

import java.net.HttpURLConnection;

我能够执行您的程序，并产生以下输出：

size of all link and images list81
https://makemysushi.com/404#navigation
https://makemysushi.com/
https://makemysushi.com/
https://makemysushi.com/sushi-university
https://makemysushi.com/sushi-recipes
https://makemysushi.com/sushi-essentials
https://makemysushi.com/store
https://www.facebook.com/Makemysushi/
https://www.instagram.com/explore/tags/makemysushi/
https://plus.google.com/+Makemysushi
mailto:info@makemysushi.com   // <-- this href attribute is of MailToURLConnection type raising the java.lang.ClassCastException which can't be casted to HttpURLConnection type
.
.
.
https://makemysushi.com/Sushi-share/contact-us
https://makemysushi.com/Sushi-share/about-us
null
null
null
null
size of activelink list77
https://makemysushi.com/404#navigation----Not Found
https://makemysushi.com/----OK
https://makemysushi.com/----OK
https://makemysushi.com/sushi-university----OK
https://makemysushi.com/sushi-recipes----OK
https://makemysushi.com/sushi-essentials----OK
https://makemysushi.com/store----OK
https://www.facebook.com/Makemysushi/----OK
https://www.instagram.com/explore/tags/makemysushi/----OK
https://plus.google.com/+Makemysushi----OK
Exception in thread "main" java.lang.ClassCastException: sun.net.www.protocol.mailto.MailToURLConnection cannot be cast to java.net.HttpURLConnection
    at demo.TestMakeMySushi.main(TestMakeMySushi.java:48)

原因

列表 活动列表包含一个元素：

<a href="mailto:info@makemysushi.com" target="_blank"><i id="social-em" class="fa fa-envelope-square fa-3x social"></i></a>

当您尝试通过 href 属性 mailto：info@makemysushi.com 建立连接时，如下所示：

HttpURLConnection connection = (HttpURLConnection) new URL(activelist.get(j).getAttribute("href")).openConnection();

无法建立成功的连接，因为 MailToURLConnection 对象无法转换为 HttpURLConnection 对象并引发 java.lang.ClassCastException

Answer 3

我因为导入而面临相同的问题

导入com.sun.net.ssl.HttpsURLConnection;

删除该文件，然后在下面导入

导入javax.net.ssl.HttpsURLConnection;

sun.net.www.protocol.https.HttpsURLConnectionImpl无法转换为sun.net.www.protocol.http.HttpURLConnection

3 个答案:

原因