Injecting HTTP Headers using Spring Framework's @RequestHeader annotation.

In this video, I will discuss how to inject the request headers in Spring Framework. We will use @RequestHeader annotation provided in Spring.

We will create an interface and use its implementation for checking the headers injection. The interface name is IHello, and the implementation is HelloImpl. We will look at all the methods one by one. At the end, I will provide the entire codebase for interface and implementation. I will use POSTMAN to run GET requests.

3 different ways you can read all the headers.
1. Using java.util.Map
2. Using org.springframework.util.MultiValueMap
3. Using org.springframework.http.HttpHeaders

You can also read one header at a time using name parameter of @RequestHeader annotation.

Introduction: 0:00
Reading all headers using Map: 3:03
Reading all headers using MultivaluedMap: 3:37
Reading all headers using HttpHeaders: 4:14
Reading specific header using @RequestHeader(name="request-id"): 5:02
Reading non-mandatory specific header using @RequestHeader(name = "request-id", required = false): 5:59
Reading specific header and providing default value using @RequestHeader(name = "request-id", defaultValue = "default-value"): 6:41

Links:
Blog article: https://justamonad.com/injecting-headers-in-spring-rest-controller-requestheader/
IHello Interface: https://github.com/savanibharat/justamonad-tutorials/blob/master/justamonad-tutorials-spring/src/main/java/com/justamonad/tutorials/spring/rest/IHello.java
HelloImpl implementation: https://github.com/savanibharat/justamonad-tutorials/blob/master/justamonad-tutorials-spring/src/main/java/com/justamonad/tutorials/spring/rest/HelloImpl.java