为了提高测试效率，测试需要同时在多个android设备上运行，就需要启动多个appium。
启动appium时，为每个设备设置不同的端口号，并为driver设置该设备的udid。见如下实例，关键是红色部分
DesiredCapabilities capabilities = new DesiredCapabilities();
capabilities.setCapability(CapabilityType.BROWSER_NAME, "");
capabilities.setCapability("deviceName", "minote");
capabilities.setCapability("udid", "AQPRBMWGJN45CMR8");
//设置每次运行不重新启动被测试app
capabilities.setCapability("noReset","true");
capabilities.setCapability("fullReset","false");
//设置安卓系统版本
capabilities.setCapability("platformVersion", "4.4");
capabilities.setCapability("platformName", "Android");
capabilities.setCapability("device", "selendroid");
capabilities.setCapability("app", app.getAbsolutePath());
String abc = app.getAbsolutePath();
//设置app的主包名和主类名 微信程序包名和activity 名
capabilities.setCapability("appPackage", "com.tencent.mm");
capabilities.setCapability("appActivity", "com.tencent.mm.ui.LauncherUI");
//启动
try {
driver = new AndroidDriver(new URL("http://127.0.0.1:4725/wd/hub"),capabilities);
} catch (MalformedURLException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}