The PUT method is used to update resources. To update a resource, we first need its representation in the client. Then, at the client level, we update the resource with the new value(s) that we want. Finally, we update the resource by using a PUT request together with the representation as its payload.

In this example, let's add a manager to the Sales department, which we created in the previous example.

Our original representation of the Sales department is as follows:

{"departmentId":40,"departmentName":"Sales","manager":"Tony 
   Greig" }

Let's update the manager for the Sales department; our representation is as follows:

{"departmentId":40,"departmentName":"Sales","manager":"Ki Gee"} 

We are now ready to connect to our web service to update the Sales department by sending the PUT request to http://www.packtpub.com/resources/departments/Sales. The sequence diagram of our PUT request is as follows:

The series of steps for the PUT request is as follows:

1. A Java client makes a PUT request to http://www.packtpub.com/resources/departments/Sales with the JSON payload representing the modified department details.
2. The server receives the request and lets the REST framework handle it. At this point, we let our code execute the proper commands to update the representation of the Sales department. Once completed, a response is sent back. The 204 No Content response code indicates that the server has fulfilled the request but does not return the entity body.