1. 问题描述和起因

在使用Appium1.7.0及其以下版本的时候，我们可以直接使用如下代码来创建一个AppiumDriver实例进行对安卓设备的操作。

driver = new AndroidDriver(new URL("http://127.0.0.1:4723/wd/hub"), capabilities);

但在把Appium包升级到当前最新的2.0.0版本的时候，这段代码会引发如下的一问题

当前的pom.xml相关设置如下:记得把1.7.0改成2.0.0或者是将来更高级版本

<dependency>
  <groupId>io.appium</groupId>
  <artifactId>java-client</artifactId>
  <version>2.0.0</version>
  <del><version>1.7.0</version></del>
</dependency>

2.问题分析

究其原因，发现Appium2.0.0把AppiumDriver这个类改成了抽象函数，所以到导致了这个问题

public <span style="color:#ff0000;">abstract </span>class AppiumDriver extends RemoteWebDriver implements MobileDriver,
		ContextAware, Rotatable, FindsByAccessibilityId, LocationContext,
		DeviceActionShortcuts, TouchShortcuts, InteractsWithFiles,
		InteractsWithApps, ScrollsTo {

	private final static ErrorHandler errorHandler = new ErrorHandler(
			new ErrorCodesMobile(), true);
	private URL remoteAddress;
	private RemoteLocationContext locationContext;
	private ExecuteMethod executeMethod;

	// frequently used command parameters
	protected final String KEY_CODE = "keycode";
	protected final String PATH = "path";
	private final String SETTINGS = "settings";

根据2.0.0的Changelog的第一点：

Changelog

2.0.0

<ul><li><span style="font-family: Arial, Helvetica, sans-serif;">AppiumDriver is now an abstract class, use IOSDriver and AndroidDriver which both extend it. You no longer need to include the PLATFORM_NAME desired capability since it's automatic for each class. Thanks to @TikhomirovSergey for all their work</span></li></ul><span style="font-family:Arial, Helvetica, sans-serif;"><span style="white-space:pre">		</span><span style="color:#3366ff;">AppiumDriver现在变成了一个抽象类，请使用从它继承下来的IOSDriver和AndroidDriver。你不再需要加上PLATFORM_NAME这个capability，因为代码会根据你使用的是IOSDriver或者AndroidDriver来确定究竟是哪个平台。</span>
</span><ul><li><span style="font-family: Arial, Helvetica, sans-serif;">ScrollTo() and ScrollToExact() methods reimplemented</span></li><li><span style="font-family: Arial, Helvetica, sans-serif;">Zoom() and Pinch() are now a little smarter and less likely to fail if you element is near the edge of the screen. Congratulate @BJap on their first PR!</span></li></ul>

3.问题解决

根据问题分析，把代码修改如下，使用AndroidDriver而非原来的AppiumDriver。

public class NoetPadTest {
    /**
     * Create the test case
     *
     * @param testName name of the test case
     */
	private <span style="color:#ff0000;">AndroidDriver </span>driver;

    @Before
    public void setUp() throws Exception {
        // set up appium
        File classpathRoot = new File(System.getProperty("user.dir"));
        File appDir = new File(classpathRoot, "apps");
        File app = new File(appDir, "NotePad.apk");
        DesiredCapabilities capabilities = new DesiredCapabilities();
        capabilities.setCapability("deviceName","Android");
        //capabilities.setCapability("platformVersion", "4.2");
        capabilities.setCapability("platformName", "Android");
        //capabilities.setCapability("app", app.getAbsolutePath());
        capabilities.setCapability("appPackage", "com.example.android.notepad");
        capabilities.setCapability("appActivity", "com.example.android.notepad.NotesList");
        //capabilities.setCapability("appActivity", ".NotesList");
        driver = new <span style="color:#ff0000;">AndroidDriver</span>(new URL("http://127.0.0.1:4723/wd/hub"), capabilities);
    } 

    @After
    public void tearDown() throws Exception {
        driver.quit();
    }