The Android SDK includes a virtual mobile device emulator that runs on your computer. The emulator lets you prototype, develop and test Android applications without using a physical device.
The Android emulator mimics all of the hardware and software features of a typical mobile device, except that it cannot place actual phone calls. It provides a variety of navigation and control keys, which you can “press” using your mouse or keyboard to generate events for your application. It also provides a screen in which your application is displayed, together with any other active Android applications.
There are some troubles faces to Android Emulator, which are as under:
Emulator Doesn’t Load:
Sometimes the Android emulator doesn’t start at all. This can happen if you haven’t properly closed a previous emulator. To fix this, close your software development kit and kill any of its running processes in the Windows task manager. The emulator should load properly after restarting your coding program. If you use Eclipse to develop Android apps, the emulator won’t run if your Windows user name has non-English characters. You will have to create a new user on your computer and run your SDK and the emulator while logged into the new account.
Sometimes, it might look like the emulator has problems when the problem is with your app. Make sure that you have loaded an emulator for the Android version for which you coded the app. If you use a different Android version for the emulator than your code, the app might not run well or it may not run at all. If you update your app, make sure that you load the updated file on the emulator. The changes will not take effect on the emulator if you don’t.
Wireless and Google:
The Android emulator uses your computer’s Internet connection to simulate the connection on an Android device. If your app needs to use a carrier’s wireless network to work properly, you will have trouble testing those functions on the emulator. When the other features of your app are ready, you’ll need to load your app on an actual Android device to test everything. If your app requires using one of the Google APIs, such as Gmail or Picasa, make sure that you aren’t loading a generic Android emulator. You need to load an emulator with the Google APIs, the SDKs for which are installed separately.
Make sure that you installed the Android SDKs properly following the instructions for the coding program you use. The emulator can’t work correctly if the SDKs aren’t installed in the right place. If your app does not work in the emulator, look at your Java code to make sure that you haven’t made a mistake. Finally, make sure that you have the correct version of Java running on your computer. Android requires Sun Java and will not work correctly with the open source alternatives.