今天把默认浏览器改成chrome，结果一运行脚本就报错，具体错误信息如下。
FAILED CONFIGURATION: @BeforeClass beforeClass
org.openqa.selenium.WebDriverException: unknown error: cannot get automation extension
from unknown error: page could not be found: chrome-extension://aapnijgdinlhnhlmodcfapnahmbfebeb/_generated_background_page.html
(Session info: chrome=59.0.3071.115)
(Driver info: chromedriver=2.27.440174 (e97a722caafc2d3a8b807ee115bfb307f7d2cfd9),platform=Windows NT 6.1.7601 SP1 x86_64) (WARNING: The server did not provide any stacktrace information)
Command duration or timeout: 10.12 seconds
Build info: version: '2.41.0', revision: '3192d8a6c4449dc285928ba024779344f5423c58', time: '2014-03-27 11:29:39'
System info: host: 'admin2-PC', ip: '10.2.16.2', os.name: 'Windows 7', os.arch: 'amd64', os.version: '6.1', java.version: '1.7.0_17'
Session ID: a2cffef46bdbde6af4e7ec75998d2bd9
Driver info: org.openqa.selenium.chrome.ChromeDriver
Capabilities [{platform=XP, acceptSslCerts=true, javascriptEnabled=true, browserName=chrome, chrome={userDataDir=C:MyTempscoped_dir6928_24278, chromedriverVersion=2.27.440174 (e97a722caafc2d3a8b807ee115bfb307f7d2cfd9)}, networkConnectionEnabled=false, unexpectedAlertBehaviour=, rotatable=false, locationContextEnabled=true, mobileEmulationEnabled=false, version=59.0.3071.115, pageLoadStrategy=normal, takesHeapSnapshot=true, databaseEnabled=false, cssSelectorsEnabled=true, handlesAlerts=true, browserConnectionEnabled=false, nativeEvents=true, webStorageEnabled=true, hasTouchScreen=false, applicationCacheEnabled=false, takesScreenshot=true}]
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at org.openqa.selenium.remote.ErrorHandler.createThrowable(ErrorHandler.java:193)
at org.openqa.selenium.remote.ErrorHandler.throwIfResponseFailed(ErrorHandler.java:145)
at org.openqa.selenium.remote.RemoteWebDriver.execute(RemoteWebDriver.java:595)
at org.openqa.selenium.remote.RemoteWebDriver$RemoteWebDriverOptions$RemoteWindow.maximize(RemoteWebDriver.java:825)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:108)
at org.testng.internal.Invoker.invokeConfigurationMethod(Invoker.java:523)
at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:224)
at org.testng.internal.Invoker.invokeConfigurations(Invoker.java:146)
at org.testng.internal.TestMethodWorker.invokeBeforeClassMethods(TestMethodWorker.java:166)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:105)
at org.testng.TestRunner.privateRun(TestRunner.java:744)
at org.testng.TestRunner.run(TestRunner.java:602)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:380)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:375)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:340)
at org.testng.SuiteRunner.run(SuiteRunner.java:289)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1301)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1226)
at org.testng.TestNG.runSuites(TestNG.java:1144)
at org.testng.TestNG.run(TestNG.java:1115)
at org.testng.remote.AbstractRemoteTestNG.run(AbstractRemoteTestNG.java:132)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:230)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:76)
找了很久才发现原来是我的chromedriver.exe版本太旧了，升级到最新版后就好了。在这里有一个小问题， Selenium的版本规则是大版本号+小版本号，所以：
2.1远远早于2.10
2.9比2.10早
各个版本的时间顺序从新到旧是：
2.19>2.10>2.9>2.1
http://selenium-release.storage.googleapis.com/index.html
Chrome Driver:
http://chromedriver.storage.googleapis.com/index.html
PhantomJS Driver:
http://phantomjs.org/download.html