How to Dynamically Register and Unregister Spring Boot Controllers at Runtime

1. Introduction

While Spring Boot normally registers controllers using @Controller or @RestController together with @RequestMapping (or its shortcuts such as @GetMapping , @PostMapping ), it also provides a programmatic way to register handler methods dynamically for advanced scenarios.

2. Practical Examples

2.1 Simple Example

First define a handler class that processes a request.

<code>@Component
public class UserHandler {
  @ResponseBody
  public User getUser(@PathVariable Long id) {
    return new User(id, "姓名 - " + id);
  }
}
</code>

Then register the handler method programmatically.

<code>@Configuration
public class MappingConfig {
  @Autowired
  public void setHandlerMapping(RequestMappingHandlerMapping mapping, UserHandler handler) throws NoSuchMethodException {
    RequestMappingInfo info = RequestMappingInfo.paths("/reg/{id}")
        .methods(RequestMethod.GET)
        .build();
    Method method = UserHandler.class.getMethod("getUser", Long.class);
    mapping.registerMapping(info, handler, method);
  }
}
</code>

Result of the test request:

2.2 Adding Constraints

You can add additional request constraints such as required parameters or headers.

<code>RequestMappingInfo info = RequestMappingInfo.paths("/reg/{id}")
    .params("type=1")
    .build();
</code>

This mapping only matches URLs like http://localhost:8888/reg/666?type=1 .

<code>RequestMappingInfo info = RequestMappingInfo.paths("/reg/{id}")
    .headers("x-token")
    .build();
</code>

The request must contain the header x-token (value can be any).

2.3 Custom Matching Conditions

If built‑in metadata is insufficient, you can implement a custom RequestCondition to define your own matching logic.

<code>public class PackRequestCondition implements RequestCondition<PackRequestCondition> {
  public PackRequestCondition combine(PackRequestCondition other) { return this; }
  public PackRequestCondition getMatchingCondition(HttpServletRequest request) {
    if (SecuritytHolder.hasRole(request)) {
      return this;
    }
    return null;
  }
  public int compareTo(PackRequestCondition other, HttpServletRequest request) { return 0; }
}
</code>

<code>RequestMappingInfo info = RequestMappingInfo.paths("/reg/{id}")
    .customCondition(new PackRequestCondition())
    .build();
</code>

2.4 Unregistering Endpoints

Maintain a map of all dynamically registered mappings and provide an endpoint to unregister them.

<code>public static final Map<String, RequestMappingInfo> MAPPINGS = new ConcurrentHashMap<>();
// registration example
MAPPINGS.putIfAbsent("1", info);
mapping.registerMapping(info, handler, method);
</code>

<code>@RestController
@RequestMapping("/mappings")
public class MappingController {
  private final RequestMappingHandlerMapping mapping;
  @GetMapping("/unregister/{key}")
  public ResponseEntity<String> unregister(@PathVariable String key) {
    this.mapping.unregisterMapping(MAPPINGS.get(key));
    return ResponseEntity.ok("success");
  }
}
</code>

The above code completes the management of dynamic registration and removal of Spring Boot controller endpoints.