Resty is a small, convenient API to talk to RESTful services from Java. Its focus is on simplicity and ease-of-use, often requiring only two lines of code to access RESTful Web services. It lets you use much less code than URLConnection, it's simpler than Apache HTTP client, and it's more reliable than Jersey client.
RestyGWT is a GWT generator for REST services and JSON encoded data transfer objects. RestyGWT Rest Services allow you to define an asynchronous service API which is then implemented via GWT deferred binding by RestyGWT. It features generation of asynchronous RESTful JSON based service proxies, encoding and decoding of Java objects to JSON, and an easy-to-use REST API.
RoboZombie allows easy integration with remote services by allowing you to replicate an endpoint contract and generate a proxy to access it. Contracts can be very flexible in terms of the resources they access. These could be vary from static HTML content or an RRS feed, to a RESTful web service endpoint. Each endpoint contract is specified on a single interface using annotations to provide the communication metadata. It is then wired into your code via an annotation, where it is created, cached, and injected at runtime.
SOAP/REST Mock Service is a simple configurable framework to mock out SOAP or RESTful (or "REST-like") Web services. Its main goal is to support automated integration testing of applications that integrate with 3rd party Web services. Functionality and usage scenarios of the mock service are in a way analogous to unit testing mocking tools (like Mockito or EasyMock). Once properly configured, SOAP/REST Mock Service exposes Web service mocks that can be called from application code and controlled via a REST interface from integration test code (setup, verify, etc.).