java WebDriverException：无法创建新会话，因为找不到使用HttpClient、InputStream和long的“createSession”

Question

我正在尝试我的第一个appium示例（API演示）

下面是我正在运行的示例代码

File f = new File("src");
File fs = new File(f,"ApiDemos-debug.apk");

//Set the Desired Capabilities
DesiredCapabilities caps = new DesiredCapabilities();

caps.setCapability(MobileCapabilityType.APP, fs.getAbsolutePath());

caps.setCapability("udid", "712KPYR0867800");
caps.setCapability(MobileCapabilityType.DEVICE_NAME, "Pixel 2 XL"); 
caps.setCapability("platformName", "Android");
caps.setCapability("platformVersion", "8.1.0");

//Instantiate Appium Driver
try {
    AppiumDriver<MobileElement> driver = new AndroidDriver<MobileElement>(new URL("http://127.0.0.1:4723/wd/hub"), caps);

} catch (MalformedURLException e) {
    System.out.println(e.getMessage());

}

当我试图在真实设备上运行上述代码时，我遇到了以下异常

Exception in thread "main" org.openqa.selenium.WebDriverException: It is impossible to create a new session because 'createSession' which takes HttpClient, InputStream and long was not found or it is not accessible'

Driver info: driver.version: AndroidDriver
at io.appium.java_client.remote.AppiumCommandExecutor$1.createSession(AppiumCommandExecutor.java:195)
at io.appium.java_client.remote.AppiumCommandExecutor.createSession(AppiumCommandExecutor.java:209)
at io.appium.java_client.remote.AppiumCommandExecutor.execute(AppiumCommandExecutor.java:231)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:548)
at io.appium.java_client.DefaultGenericMobileDriver.execute(DefaultGenericMobileDriver.java:42)
at io.appium.java_client.AppiumDriver.execute(AppiumDriver.java:1)
at io.appium.java_client.安卓.AndroidDriver.execute(AndroidDriver.java:1)
at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:212)
at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:130)
at io.appium.java_client.DefaultGenericMobileDriver.<init>(DefaultGenericMobileDriver.java:38)
at io.appium.java_client.AppiumDriver.<init>(AppiumDriver.java:84)
at io.appium.java_client.AppiumDriver.<init>(AppiumDriver.java:94)
at io.appium.java_client.安卓.AndroidDriver.<init>(AndroidDriver.java:93)
at com.appium.example.FirstTestAppiumClass.main(FirstTestAppiumClass.java:37)

Caused by: org.openqa.selenium.WebDriverException: An unknown server-side error occurred while processing the command. Original error: Could not find a connected Android device.

谢谢你的帮助