Jersy and Jax-rs

Jersey just a interface to use JAX-rs in more easier way. JAX-RS don't provided servlet but Jersey does. Jersey provides a library to implement Restful webservices in a Java servlet container, Jersey provides a servlet implementation which scans predefined classes to identify RESTful resources. In your web.xml configuration file your register this servlet for your web application

GET request to /api/user/ returns a list of users
GET request to /api/user/1 returns the user with ID 1
POST request to /api/user/ with a user object as JSON creates a new user
PUT request to /api/user/3 with a user object as JSON updates the user with ID 3 //upload
DELETE request to /api/user/4 deletes the user with ID 4
DELETE request to /api/user/ deletes all the users