AppiumDriver空指针异常通过环境变量确定平台

Question

Appium驱动程序在通过环境变量确定平台时抛出空指针异常。

*这是我的代码*

public class AppiumBaseClass {     公共AppiumDriver驱动程序;

@BeforeClass
public void setup() throws Exception {

    Properties prop = new Properties();
    InputStream input = null;
    String platform = System.getenv("PLATFORM");

    try {
        input = 
        new FileInputStream("/Users/piyushkumar/Desktop/Automation_Framework/HP_Signup/src/main/java/Utility/appiumSession.properties");
        prop.load(input);

        DesiredCapabilities capabilities = new DesiredCapabilities();
        capabilities.setCapability("automation name", prop.getProperty("automation name"));
        capabilities.setCapability("platform",prop.getProperty("platform"));
        capabilities.setCapability("platformName", prop.getProperty("platformName"));
        capabilities.setCapability("platformversion", prop.getProperty("platformversion"));
        capabilities.setCapability("deviceName", prop.getProperty("deviceName"));
        capabilities.setCapability("app", prop.getProperty("app"));
        capabilities.setCapability("newCommandTimeout", "60");


        //Checking the platform
        if (platform.equals("Android")) {
            driver = new AndroidDriver(
                new URL("http://localhost:4723/wd/hub"), capabilities);
        } else if (platform.equals("ios")) {
            driver = new IOSDriver(new URL("http://localhost:4723/wd/hub"), capabilities);

        } else {
            throw new Exception("Unable to read platform");
        }

    } catch (IOException io) {
        io.printStackTrace();
        Reporter.log("platform selected is "+driver);
    }
}

}

appiumSession.properties

这是属性文件的内容。

automation name = Appium
platformName= Android
platformversion=5.1
deviceName=Nexus_S_API_22
app= /Users/piyushkumar/Desktop/SignUpApp-qa-release-2.6-unaligned.apk
platform =Android

任何帮助将不胜感激。