Overview (Google App Engine API for Java 8)

Google App Engine API for Java

Packages 
Package Description
com.google.appengine.api
Provides facilities for server lifecycle management, threading and namespaces/multitenancy.
com.google.appengine.api.appidentity
Provides a service to sign arbitrary byte arrays using an internally-generated, rotated private key.
com.google.appengine.api.backends
Provides access to long-running, addressable servers.
com.google.appengine.api.blobstore
Provides management and persistent storage of large, immutable byte arrays.
com.google.appengine.api.capabilities
Provides status information about the services available via the Google App Engine APIs.
com.google.appengine.api.datastore
Provides persistent storage, also accessible via JDO or JPA interfaces.
com.google.appengine.api.files
Provides a service for file storage and access.
com.google.appengine.api.images
Provides facilities for the creation and manipulation of images.
com.google.appengine.api.log
Provides access to request logs and application logs.
com.google.appengine.api.mail
Provides a service to send email messages on behalf of administrators or authenticated users, also accessible via a JavaMail interface.
com.google.appengine.api.memcache
Provides fast but unreliable data storage, also accessible via a JCache interface.
com.google.appengine.api.modules
Utility functions for working with modules.
com.google.appengine.api.oauth
Provides a method for clients to access server resources on behalf of a resource owner, as well as a process for end-users to authorize third-party access to their server resources without sharing their credentials.
com.google.appengine.api.quota
Provides measurement of API and CPU usage during requests.
com.google.appengine.api.search
Provides a service for indexing documents and retrieving them using search queries.
com.google.appengine.api.search.checkers  
com.google.appengine.api.search.query  
com.google.appengine.api.taskqueue
Provides a mechanism to perform work initiated by a user request, outside of that request.
com.google.appengine.api.urlfetch
Provides a service to make HTTP/S requests of other servers on the internet.
com.google.appengine.api.users
Provides facilities to check if a user has authenticated, retrieve their email address, and check if they are an administrator for this application.
com.google.appengine.api.utils
Provides common utility classes.
com.google.apphosting.api
Provides access to the ApiProxy, which dispatches API calls to backend services.