Feat : add HealthController with tests and update documentation for Java 21

readme.md

@@ -19,6 +19,12 @@ The [spring-petclinic-angular project](https://github.com/spring-petclinic/sprin
 ## Running Petclinic locally
 
 ### With Maven command line
+### 🧩 Running PetClinic on Java 21
+
+This project also runs smoothly on **Java 21** (tested on JDK 21.0.5).  
+If you're using Java 21, follow these steps to ensure a clean setup:
+
+1. **Clone the repository**
 ```sh
 git clone https://github.com/spring-petclinic/spring-petclinic-rest.git
 cd spring-petclinic-rest

src/main/java/org/springframework/samples/petclinic/rest/controller/HealthController.java

@@ -0,0 +1,14 @@
+package org.springframework.samples.petclinic.rest.controller;
+
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+import java.util.Map;
+
+@RestController
+public class HealthController {
+
+    @GetMapping("/api/health")
+    public Map<String, String> healthCheck() {
+        return Map.of("status", "ok");
+    }
+}

src/test/java/org/springframework/samples/petclinic/rest/controller/HealthControllerTests.java

@@ -0,0 +1,28 @@
+package org.springframework.samples.petclinic.rest.controller;
+
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
+import org.springframework.security.test.context.support.WithMockUser;
+import org.springframework.test.web.servlet.MockMvc;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@WebMvcTest(HealthController.class)
+@AutoConfigureMockMvc(addFilters = false)
+class HealthControllerTests {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Test
+    @WithMockUser
+    void healthShouldReturnOk() throws Exception {
+        mockMvc.perform(get("/api/health"))
+            .andExpect(status().isOk())
+            .andExpect(jsonPath("$.status").value("ok"));
+    }
+}