org.openqa.selenium.NoSuchSessionException：会话ID为null。调用quit（）后使用WebDriver吗？

Question

我已经进行了一些搜索，但是仍然遇到相同的问题。我相信这可能是因为我的网络驱动程序是静态的吗？我不太确定...

在我的主要课堂上，我加入了@BeforeTest和@AfterTest。 @BeforeTest包括启动取决于我的XML文件中的新的浏览器 @AfterTest包括driver.quit()，应终止会话/驱动程序，以便第二次测试可以从一个干净的司机@BeforeTest，不是吗？

这是我的浏览器声明：

public class Browser {  
public static WebDriver driver;
//Variable initialization
public static String title;
public static String url;
public static String currentBrowser;
public static boolean jseWorkAround;

public Browser(){
    driver.manage().timeouts().implicitlyWait(5, TimeUnit.SECONDS);
}

//Browser launch
public static void launch(String browser){
    if(browser.equalsIgnoreCase("firefox")){
        driver = new FirefoxDriver();
        currentBrowser = "Firefox/";
        jseWorkAround = false;
        System.out.println("Firefox Selected");
    } else if (browser.equalsIgnoreCase("chrome")){
        driver = new ChromeDriver();
        currentBrowser = "Chrome/";
        jseWorkAround = false;
        System.out.println("Chrome Selected");
    } else if (browser.equalsIgnoreCase("edge")){
        driver = new EdgeDriver();
        currentBrowser = "Edge/";
        jseWorkAround = true;
        System.out.println("Edge selected");
    } else if (browser.equalsIgnoreCase("ie")){
        driver = new InternetExplorerDriver();
        currentBrowser = "IE/";
        jseWorkAround = true;
        System.out.println("IE Driver Selected");
    } else if (browser.equalsIgnoreCase("background")){
        driver = new PhantomJSDriver();
        currentBrowser = "Background/";
        jseWorkAround = false;
        System.out.println("Background selected");
    } else {
        throw new IllegalArgumentException("Invalid Browser");
    }
}

public static void quit(){
    driver.quit();
}

public static void goToPage(String pageurl){
    driver.get(pageurl);
}

这是一个随机样本测试：

    @Parameters({"browser"})
    @BeforeTest
    public void browserSelection(String browser){
        Browser.launch(browser);
    }

    @AfterTest
    public void cleanupAfterTest(){
        Print.line("Test complete. Cleaning up...");
        Browser.quit();
    }

    @Test
    public void Test1() {
        Browser.goToPage("http://www.google.com");
        Screenshot.page("Goes to google");

    }
    @Test
    public void Test2() {
        Browser.goToPage("http://www.yahoo.com");
        Screenshot.page("Goes to yahoo");

    }

我注意到当事情开始失败并出现错误“调用quit之后调用webdriver”时，它总是第二次测试的结尾。浏览器之间的测试根据我testng.xml文件中提到的顺序顺序进行。如果我先运行Firefox，然后运行chrome，则chrome测试将在最后运行失败@Test。而如果我先运行chrome，然后运行Firefox，则Firefox最终将失败@Test。

以下是错误消息...

org.openqa.selenium.NoSuchSessionException: Session ID is null. Using WebDriver after calling quit()?
Build info: version: 'unknown', revision: '1969d75', time: '2016-10-18 09:43:45 -0700'
System info: host: 'DESKTOP-5ED0H7O', ip: '10.0.9.239', os.name: 'Windows 10', os.arch: 'amd64', os.version: '10.0', java.version: '1.8.0_121'
Driver info: driver.version: RemoteWebDriver
    at org.openqa.selenium.remote.HttpCommandExecutor.execute(HttpCommandExecutor.java:130)
    at org.openqa.selenium.remote.service.DriverCommandExecutor.execute(DriverCommandExecutor.java:82)
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:601)
    at org.openqa.selenium.remote.RemoteWebDriver.executeScript(RemoteWebDriver.java:537)
    at utility.Scroll.toText(Scroll.java:43)
    at tests.TestCases.TCID20(TestCases.java:390)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:108)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:661)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:869)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1193)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:126)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
    at org.testng.TestRunner.privateRun(TestRunner.java:744)
    at org.testng.TestRunner.run(TestRunner.java:602)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:380)
    at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:375)
    at org.testng.SuiteRunner.privateRun(SuiteRunner.java:340)
    at org.testng.SuiteRunner.run(SuiteRunner.java:289)
    at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
    at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
    at org.testng.TestNG.runSuitesSequentially(TestNG.java:1301)
    at org.testng.TestNG.runSuitesLocally(TestNG.java:1226)
    at org.testng.TestNG.runSuites(TestNG.java:1144)
    at org.testng.TestNG.run(TestNG.java:1115)
    at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:132)
    at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:230)
    at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:76)

这种随机的失败严重损害了我的进步。如果我一次只在我的XML文件上启用一个浏览器，而没有其他浏览器在线，则没有任何故障。

Answer 1

正如我所看到的，你的问题是 @test 在加载浏览器之前运行（你必须增加等待时间）。另一件事是您没有添加任何优先级。首先是您获取浏览器的方式。你必须使用 geckodriver、chromedriver 等。

尝试使用如下浏览器

if (browser.equalsIgnoreCase("chrome")){
       System.setProperty("webdriver.chrome.driver", "/Path/ToChromeDriver/chromedriver.exe");
        driver = new ChromeDriver();
        System.out.println("Chrome Selected");
}

添加如下优先级

Browser browser;

@Parameters({"browser"})
@BeforeTest
public void browserSelection(String browser){
    browser.launch(browser);
    thread.sleep(5000);//Not recommended but timeout also may be an issue if so increase implicitly wait time 
}

@AfterTest
public void cleanupAfterTest(){
    Print.line("Test complete. Cleaning up...");
    browser.quit();
}

@Test( priority = 1, description = "Test 1")
public void setUserName(){
    Browser.goToPage("http://www.google.com");
    Screenshot.page("Goes to google");
}

@Test(priority = 2,description = "Test 2")
public void setPassword(){
    Browser.goToPage("http://www.yahoo.com");
    Screenshot.page("Goes to yahoo");
}