Using the Google HTTP Client Library for Java on Google App Engine

Google App Engine is one of the supported Java environments for the Google HTTP Client Library for Java.

Data models

JSON

The JSON data model is optimized for efficient memory usage that minimizes parsing and serialization time. Only the fields you need are actually parsed when processing a JSON response.

For your JSON parser, we recommend JacksonFactory, which is based on the popular Jackson library. It is considered the fastest in terms of parsing/serialization. You can also use `GsonFactory’, which is based on the Google GSON library. It is a lighter-weight option (smaller size) that is fairly fast, but it is not quite as fast as Jackson.

XML (@Beta)

The XML datamodel (@Beta) is optimized for efficient memory usage that minimizes parsing and serialization time. Only the fields you need are actually parsed when processing an XML response.

HTTP transport

If you have configured Google App Engine to use urlfetch as the stream handler, then you will use the UrlFetchTransport provided by google-http-client-appengine.

If you are not using urlfetch, then you can use any of the provided HttpTransport adapters.