The Google Plugin for Eclipse adds several buttons to the Eclipse toolbar. The App Engine deploy button uploads your application to App Engine:
Before you upload your app for the first time, you must register an application ID with App Engine using the Admin Console. Register an application ID, then edit the appengine-web.xml file and change the <application>Student details(application name)</application> element to contain the new ID.
When you click the App Engine deploy button, Eclipse prompts you for your administrator account username (your email address) and password. Enter your account information and click the Upload button to complete the upload. Eclipse gets the application ID and version information from the appengine-web.xml file, and uploads the contents of the war/ directory.
Test your application on App Engine by visiting its URL: