@RequestParam vs @PathVariable

In Spring MVC, the @RequestParam annotation is used to bind a request parameter to a method parameter. It is typically used to extract query parameters or form data from an HTTP request.

On the other hand, the @PathVariable annotation is used to bind a URI template variable to a method parameter. It is typically used to extract values from the path portion of a URI, such as the value of an ID in a RESTful API.

Here's an example of how you can use the @RequestParam and @PathVariable annotations in a Spring MVC controller:

import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/users")
public class UserController {
  @RequestMapping("/search")
  public String search(@RequestParam("q") String query) {
    // search for users based on the query parameter
    return "Search results for: " + query;
  }

  @RequestMapping("/{id}")
  public String getById(@PathVariable("id") String id) {
    // get user by id
    return "User with ID " + id;
  }
}

This code defines a UserController with two request mapping methods: search and getById. The search method is mapped to the /search path and uses the @RequestParam annotation to bind the q request parameter to the query method parameter. The getById method is mapped to the /{id} path and uses the @PathVariable annotation to bind the id URI template variable to the id method parameter.

I hope this helps! Let me know if you have any questions.