In this chapter, you learned that JAX-RS can automatically convert Java objects to a specific data type format and write it out as an HTTP response. It can also automatically read in HTTP request bodies and create specific Java objects that represent the request. JAX-RS has a number of built-in handlers, but you can also write your own custom marshallers and unmarshallers. Chapter 21 walks you through some sample code that you can use to test-drive many of the concepts and APIs introduced in this chapter.