What is the role and purpose of different types of routers in Java?

In Java, the term "router" is not a standard concept of the language, but in the context of web applications and frameworks (such as Spring MVC, JAX-RS), routers are responsible for matching incoming HTTP requests with the corresponding handlers (controllers).

Different types of routers may include:

• Static routers — match fixed URL paths with handlers.
• Dynamic routers — support parameters in the path, for example /user/{id}.
• Filters and interceptors — intermediate handlers that can modify the request or response.

Overall, the role of a router is to direct requests to the appropriate components of the application, ensuring correct processing and logic.

Example using Spring MVC:

@RestController
@RequestMapping("/users")
public class UserController {

    @GetMapping("/{id}")
    public User getUser(@PathVariable String id) {
        // request processing
    }
}

Here, Spring acts as a router, directing requests /users/{id} to the getUser method.