RESTful Java Web Services - Third Edition

Conditional data update in RESTful web services

In the previous two sections, we learned how to leverage HTTP caching features to optimize read operations (the HTTP GET type) in RESTful web APIs. In this section, we will discuss how to leverage these features during the entity updates in these APIs (the HTTP POST or PUT request types). Conditional updates help you to avoid performing modifications on the stale representation of resources, thereby avoiding the overwriting of changes performed by other users of the system on the same resource. You can perform conditional updates by using either of the following approaches:

• Comparing the last modified date of the resource: When a client sends a modified resource to the server via the PUT or ...