add spotify feature

src/main/java/cc/fascinated/bat/controller/SpotifyController.java

@@ -0,0 +1,33 @@
+package cc.fascinated.bat.controller;
+
+import cc.fascinated.bat.service.SpotifyService;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * @author Fascinated (fascinated7)
+ */
+@RestController
+@RequestMapping(value = "/spotify")
+public class SpotifyController {
+    private final SpotifyService spotifyService;
+
+    @Autowired
+    public SpotifyController(SpotifyService spotifyService) {
+        this.spotifyService = spotifyService;
+    }
+
+    /**
+     * A GET request to authorize the user with Spotify.
+     *
+     * @return the response entity
+     */
+    @GetMapping(value = "/callback")
+    public ResponseEntity<String> authorizationCallback(@RequestParam String code) {
+        return ResponseEntity.ok(spotifyService.authorize(code));
+    }
+}