解决Appium报错UiAutomator quit before it successfully launched

报错信息如下：

org.openqa.selenium.SessionNotCreatedException: A new session could not be created. (Original error: UiAutomator quit before it successfully launched) (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 12.11 seconds
Build info: version: '2.44.0', revision: '76d78cf323ce037c5f92db6c1bba601c2ac43ad8', time: '2014-10-23 13:11:40'
System info: host: 'admin-PC', ip: '172.31.59.210', os.name: 'Windows 7', os.arch: 'amd64', os.version: '6.1', java.version: '1.8.0_101'
Driver info: io.appium.java_client.AppiumDriver
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
    at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:204)
    at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:156)
    at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:599)
    at io.appium.java_client.AppiumDriver.execute(AppiumDriver.java:81)
    at org.openqa.selenium.remote.RemoteWebDriver.startSession(RemoteWebDriver.java:240)
    at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:126)
    at org.openqa.selenium.remote.RemoteWebDriver.<init>(RemoteWebDriver.java:153)
    at io.appium.java_client.AppiumDriver.<init>(AppiumDriver.java:43)
    at com.company.history.geturl_viewhistory.getUrlByXiaoMi4CTest.f(getUrlByXiaoMi4CTest.java:100)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:85)
    at org.testng.internal.Invoker.invokeMethod(Invoker.java:659)
    at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:845)
    at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1153)
    at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
    at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:108)
    at org.testng.TestRunner.privateRun(TestRunner.java:771)
    at org.testng.TestRunner.run(TestRunner.java:621)
    at org.testng.SuiteRunner.runTest(SuiteRunner.java:357)
    at org.testng.SuiteRunner.access$000(SuiteRunner.java:38)
    at org.testng.SuiteRunner$SuiteWorker.run(SuiteRunner.java:391)
    at org.testng.internal.thread.ThreadUtil$2.call(ThreadUtil.java:64)
    at java.util.concurrent.FutureTask.run(FutureTask.java:266)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
    at java.lang.Thread.run(Thread.java:745)

问题原因：为了让adb.exe释放端口供chromedriver使用，每轮测试完成后需要结束adb.exe进程，这样就会产生一个UiAutomator quit的问题。

解决办法：使用taskkill adb.exe后，为了让手机与电脑稳定连接，使用adb start-server来保持连接。

Runtime.getRuntime().exec("taskkill /f /im adb.exe");
Thread.sleep(3000);
Runtime.getRuntime().exec("adb start-server");