How to preserve Appium session between multiple testng class

Question

I am automating Android application using Appium, I have One Base Class with Setup and Tear down (In setup initialization appium session and in teardown destroying session )

Answer 1

I have implemented this approach using Singlton design pattern here is approach:

public class SingltonFactory{

    private static SingltonFactory instance = new SingltonFactory();
    private static AppiumDriver driver;

    private SingltonFactory() {
    }

    // Get the only object available
    public static SingltonFactory getInstance() {
        return instance;
    }

    // Get the only object available
    public void setDriver(AppiumDriver driver1) {
        driver = driver1;
    }

    public AppiumDriver getAppiumDriver() {
        return driver;
    }   

}

Add initialize SingltonFactory in your before test cases and assign driver object like below:

AppiumFactory appiumFactory = AppiumFactory.getInstance();
if(appiumFactory.getAppiumDriver() == null) {
    driver = new AndroidDriver(new URL("http://127.0.0.1:4723/wd/hub"), cap);                
}
else{
   driver = appiumFactory.getAppiumDriver();
}