src/main/java/com/example/demo/controller/HelloController.java

@@ -0,0 +1,18 @@
+package com.example.demo.controller;
+
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class HelloController {
+
+    @GetMapping("/hello")
+    public ResponseEntity<String> hello(@RequestParam(required = false) String name) {
+        String message = (name != null && !name.isBlank())
+                ? "Hello, " + name + "!"
+                : "Hello, World!";
+        return ResponseEntity.ok(message);
+    }
+}