Google APIs Client Library for Java can be found on 
http://blog.doityourselfandroid.com/2011/04/12/oauth-android-google-apis-client-library-java/

The code has a dependency towards the google-api-java-client library.
The library can be downloaded here : http://code.google.com/p/google-api-java-client/ 

Following is a list of JARs (dependencies) that are required for the project :

google-api-client-1.3.1-alpha.jar
google-api-client-extensions-1.3.1-alpha.jar
google-api-client-googleapis-1.3.1-alpha.jar

commons-codec-1.3.jar
commons-logging-1.1.1.jar
gson-1.6.jar
guava-r08.jar
httpclient-4.0.3.jar
httpcore-4.0.1.jar
jackson-core-asl-1.6.5.jar
jsr305-1.3.9.jar