Key Differences Between @RequestParam and @PathVariable
1. Purpose:
@RequestParam: Used to extract query parameters from the URL.@PathVariable: Used to extract values from the URI path.
2. Usage Context:
@RequestParam: Typically used when parameters are passed as query strings in the URL.@PathVariable: Typically used when values are embedded directly in the URI path.
Example Scenarios
Example 1: Using @RequestParam
- Scenario:
You have an endpoint that filters users based on a query parameter.
* URL: http://example.com/users?name=John
* Controller Method:
@RestController public class UserController {
@GetMapping("/users")
public List<User> getUsersByName(@RequestParam String name) {
// Logic to retrieve users by name
return userService.findUsersByName(name);
}
}
Explanation:
- @RequestParam is used to extract the query parameter name from the URL.
- The value of name is passed to the getUsersByName method.
Example 2: Using @PathVariable
- Scenario:
You have an endpoint that retrieves a user by their ID embedded in the URL path.
* URL: http://example.com/users/123
* Controller Method:
@RestController public class UserController {
@GetMapping("/users/{id}")
public User getUserById(@PathVariable Long id) {
// Logic to retrieve user by ID
return userService.findUserById(id);
}
}
Explanation:
- @PathVariable is used to extract the id variable from the URI path.
- The value of id is passed to the getUserById method.
Conclusion
Understanding the differences between @RequestParam and @PathVariable allows you to design your Spring Boot application's endpoints more effectively, ensuring that parameters are mapped to method arguments correctly based on their context in the URL. Use @RequestParam for query parameters and @PathVariable for path variables to achieve clear and efficient URL mapping in your RESTful APIs.