RESTful Java Web Services - Third Edition

Understanding the difference between PUT and POST

A common question that you will encounter while designing a RESTful web API is when to use the PUT and POST methods? Here is the simplified answer:

You can use PUT for creating or updating a resource, when the client has the full resource content available. In this case, all values are with the client and the server does not generate a value for any of the fields.

You will use POST for creating or updating a resource if the client has only partial resource content available. Note that you are losing the idempotency support with POST. An idempotent method means that you can call the same API multiple times without changing the state. This is not true for the POST method; each POST method call ...