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);
+    }
+}

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

@@ -5,14 +5,13 @@ import cc.fascinated.player.impl.Player;
 import cc.fascinated.player.impl.Skin;
 import cc.fascinated.player.impl.SkinPart;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.CacheControl;
+import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
 import java.util.Map;
-import java.util.Objects;
 import java.util.concurrent.TimeUnit;
 
 @RestController
@@ -27,10 +26,10 @@ public class PlayerController {
     }
 
     @GetMapping(value = "/{id}", produces = MediaType.APPLICATION_JSON_VALUE) @ResponseBody
-    public ResponseEntity<Player> getPlayer(@PathVariable String id) {
+    public ResponseEntity<?> getPlayer(@PathVariable String id) {
         Player player = playerManagerService.getPlayer(id);
         if (player == null) {
-            return ResponseEntity.notFound().build();
+            return new ResponseEntity<>(Map.of("error", "Player not found"), HttpStatus.NOT_FOUND);
         }
         return ResponseEntity.ok(player);
     }

src/main/java/cc/fascinated/api/model/ErrorResponse.java

@@ -0,0 +1,40 @@
+package cc.fascinated.api.model;
+
+import com.fasterxml.jackson.annotation.JsonFormat;
+import io.micrometer.common.lang.NonNull;
+import lombok.Getter;
+import lombok.NoArgsConstructor;
+import lombok.Setter;
+import lombok.ToString;
+import org.springframework.http.HttpStatus;
+
+import java.util.Date;
+
+@NoArgsConstructor
+@Setter
+@Getter
+@ToString
+public final class ErrorResponse {
+    /**
+     * The status code of this error.
+     */
+    @NonNull
+    private HttpStatus status;
+
+    /**
+     * The message of this error.
+     */
+    @NonNull private String message;
+
+    /**
+     * The timestamp this error occurred.
+     */
+    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = "dd-MM-yyyy hh:mm:ss")
+    private Date timestamp;
+
+    public ErrorResponse(@NonNull HttpStatus status, @NonNull String message) {
+        this.status = status;
+        this.message = message;
+        timestamp = new Date();
+    }
+}