fix unknown player and add player not found response

src/main/java/cc/fascinated/api/controller/ExceptionControllerAdvice.java

@@ -0,0 +1,32 @@
+package cc.fascinated.api.controller;
+
+import cc.fascinated.api.model.ErrorResponse;
+import io.micrometer.common.lang.NonNull;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ControllerAdvice
+public final class ExceptionControllerAdvice {
+    /**
+     * Handle a raised exception.
+     *
+     * @param ex the raised exception
+     * @return the error response
+     */
+    @ExceptionHandler(Exception.class)
+    public ResponseEntity<?> handleException(@NonNull Exception ex) {
+        HttpStatus status = HttpStatus.INTERNAL_SERVER_ERROR; // Get the HTTP status
+        if (ex.getClass().isAnnotationPresent(ResponseStatus.class)) { // Get from the @ResponseStatus annotation
+            status = ex.getClass().getAnnotation(ResponseStatus.class).value();
+        }
+        String message = ex.getLocalizedMessage(); // Get the error message
+        if (message == null) { // Fallback
+            message = "An internal error has occurred.";
+        }
+        ex.printStackTrace(); // Print the stack trace
+        return new ResponseEntity<>(new ErrorResponse(status, message), status);
+    }
+}