api: add / route

API/src/main/java/cc/fascinated/controller/RootController.java

@@ -0,0 +1,25 @@
+package cc.fascinated.controller;
+
+import java.util.Map;
+
+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.ResponseBody;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * @author Fascinated (fascinated7)
+ */
+@RestController
+@RequestMapping(value = "/")
+public class RootController {
+    /**
+     * A GET mapping to show the 
+     */
+    @ResponseBody
+    @GetMapping(value = "/")
+    public ResponseEntity<?> getWelcome() {
+        return ResponseEntity.ok(Map.of("message", "Hello!"));
+    }
+}