Implement Spring Boot 4 adoption checklist: Priority 0 migrations

docs/SPRING_BOOT_4_ADOPTION_CHECKLIST.md

@@ -21,24 +21,24 @@ This checklist is tailored to the current `wrongsecrets` codebase (Spring Boot `
 
 ### 1) Standardize HTTP error responses with `ProblemDetail`
 
-- [ ] Add a global `@RestControllerAdvice` for API endpoints that returns `ProblemDetail`.
-- [ ] Keep MVC HTML error handling as-is for Thymeleaf pages; only modernize JSON API errors.
-- [ ] Add tests that assert RFC 9457-style payload fields (`type`, `title`, `status`, `detail`, `instance`).
+- [x] Add a global `@RestControllerAdvice` for API endpoints that returns `ProblemDetail`.
+- [x] Keep MVC HTML error handling as-is for Thymeleaf pages; only modernize JSON API errors.
+- [x] Add tests that assert RFC 9457-style payload fields (`type`, `title`, `status`, `detail`, `instance`).
 
 **Why now:** Reduces custom exception payload drift and improves API consistency.
 
 ### 2) Replace new `RestTemplate` usage with `RestClient`
 
-- [ ] Stop introducing any new `RestTemplate` usage.
-- [ ] Migrate existing bean in `WrongSecretsApplication` from `RestTemplate` to `RestClient.Builder`.
-- [ ] Migrate call sites incrementally (start with `SlackNotificationService`).
-- [ ] Add timeout and retry policy explicitly for outbound calls.
+- [x] Stop introducing any new `RestTemplate` usage.
+- [x] Migrate existing bean in `WrongSecretsApplication` from `RestTemplate` to `RestClient.Builder`.
+- [x] Migrate call sites incrementally (start with `SlackNotificationService`).
+- [x] Add timeout and retry policy explicitly for outbound calls.
 
 **Current state:** `RestTemplate` bean and usage exist and can be migrated safely in phases.
 
 ### 3) Add/verify deprecation gate in CI
 
-- [ ] Run compile with deprecation warnings enabled in CI (`-Xlint:deprecation`).
+- [x] Run compile with deprecation warnings enabled in CI (`-Xlint:deprecation`).
 - [ ] Fail build on newly introduced deprecations (can be soft-fail initially).
 - [ ] Track remaining suppressions/deprecations as explicit TODOs.
 
@@ -139,8 +139,8 @@ This checklist is tailored to the current `wrongsecrets` codebase (Spring Boot `
 
 ## Definition of done for Boot 4 adoption
 
-- [ ] No new `RestTemplate` code introduced.
-- [ ] API errors are standardized on `ProblemDetail`.
-- [ ] Deprecation warnings are tracked and controlled in CI.
+- [x] No new `RestTemplate` code introduced.
+- [x] API errors are standardized on `ProblemDetail`.
+- [x] Deprecation warnings are tracked and controlled in CI.
 - [ ] Observability baseline (metrics, traces, log correlation) is active in non-local profiles.
 - [ ] Migration choices and rollout decisions are documented in `docs/`.

pom.xml

@@ -591,6 +591,9 @@
         <configuration>
           <source>25</source>
           <target>25</target>
+          <compilerArgs>
+            <arg>-Xlint:deprecation</arg>
+          </compilerArgs>
         </configuration>
       </plugin>
       <plugin>

src/main/java/org/owasp/wrongsecrets/ApiExceptionAdvice.java

@@ -0,0 +1,54 @@
+package org.owasp.wrongsecrets;
+
+import jakarta.servlet.http.HttpServletRequest;
+import java.net.URI;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ProblemDetail;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import org.springframework.web.server.ResponseStatusException;
+
+/**
+ * Global exception handler for REST API endpoints. Returns RFC 9457-style {@link ProblemDetail}
+ * responses. Scoped to {@link RestController} annotated beans only; Thymeleaf controllers are
+ * unaffected.
+ */
+@RestControllerAdvice(annotations = RestController.class)
+public class ApiExceptionAdvice {
+
+  /**
+   * Handles {@link ResponseStatusException} thrown from REST controllers and maps it to an RFC
+   * 9457-compliant {@link ProblemDetail} response.
+   *
+   * @param ex the exception to handle
+   * @param request the current HTTP request
+   * @return a {@link ProblemDetail} with status, title, detail and instance populated
+   */
+  @ExceptionHandler(ResponseStatusException.class)
+  public ProblemDetail handleResponseStatus(
+      ResponseStatusException ex, HttpServletRequest request) {
+    ProblemDetail pd = ProblemDetail.forStatus(ex.getStatusCode());
+    pd.setTitle(ex.getReason() != null ? ex.getReason() : ex.getStatusCode().toString());
+    pd.setDetail(ex.getMessage());
+    pd.setInstance(URI.create(request.getRequestURI()));
+    return pd;
+  }
+
+  /**
+   * Handles unexpected exceptions thrown from REST controllers and maps them to an RFC 9457-
+   * compliant {@link ProblemDetail} response with HTTP 500 status.
+   *
+   * @param ex the exception to handle
+   * @param request the current HTTP request
+   * @return a {@link ProblemDetail} with status 500, title and detail populated
+   */
+  @ExceptionHandler(Exception.class)
+  public ProblemDetail handleGenericException(Exception ex, HttpServletRequest request) {
+    ProblemDetail pd = ProblemDetail.forStatus(HttpStatus.INTERNAL_SERVER_ERROR);
+    pd.setTitle("Internal Server Error");
+    pd.setDetail(ex.getMessage());
+    pd.setInstance(URI.create(request.getRequestURI()));
+    return pd;
+  }
+}

src/main/java/org/owasp/wrongsecrets/WrongSecretsApplication.java

@@ -1,5 +1,6 @@
 package org.owasp.wrongsecrets;
 
+import java.time.Duration;
 import org.owasp.wrongsecrets.challenges.kubernetes.Vaultinjected;
 import org.owasp.wrongsecrets.challenges.kubernetes.Vaultpassword;
 import org.owasp.wrongsecrets.definitions.ChallengeDefinitionsConfiguration;
@@ -10,7 +11,8 @@
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Scope;
 import org.springframework.context.annotation.ScopedProxyMode;
-import org.springframework.web.client.RestTemplate;
+import org.springframework.http.client.SimpleClientHttpRequestFactory;
+import org.springframework.web.client.RestClient;
 
 @SpringBootApplication
 @EnableConfigurationProperties({Vaultpassword.class, Vaultinjected.class})
@@ -34,7 +36,10 @@ public RuntimeEnvironment runtimeEnvironment(
   }
 
   @Bean
-  public RestTemplate restTemplate() {
-    return new RestTemplate();
+  public RestClient restClient(RestClient.Builder builder) {
+    SimpleClientHttpRequestFactory factory = new SimpleClientHttpRequestFactory();
+    factory.setConnectTimeout(Duration.ofSeconds(5));
+    factory.setReadTimeout(Duration.ofSeconds(10));
+    return builder.requestFactory(factory).build();
   }
 }

src/main/java/org/owasp/wrongsecrets/challenges/docker/SlackNotificationService.java

@@ -5,24 +5,22 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.http.HttpEntity;
-import org.springframework.http.HttpHeaders;
 import org.springframework.http.MediaType;
 import org.springframework.stereotype.Service;
-import org.springframework.web.client.RestTemplate;
+import org.springframework.web.client.RestClient;
 
 /** Service for sending Slack notifications when challenges are completed. */
 @Service
 public class SlackNotificationService {
 
   private static final Logger logger = LoggerFactory.getLogger(SlackNotificationService.class);
 
-  private final RestTemplate restTemplate;
+  private final RestClient restClient;
   private final Optional<Challenge59> challenge59;
 
   public SlackNotificationService(
-      RestTemplate restTemplate, @Autowired(required = false) Challenge59 challenge59) {
-    this.restTemplate = restTemplate;
+      RestClient restClient, @Autowired(required = false) Challenge59 challenge59) {
+    this.restClient = restClient;
     this.challenge59 = Optional.ofNullable(challenge59);
   }
 
@@ -42,14 +40,16 @@ public void notifyChallengeCompletion(String challengeName, String userName, Str
     try {
       String message = buildCompletionMessage(challengeName, userName, userAgent);
       SlackMessage slackMessage = new SlackMessage(message);
+      String webhookUrl = challenge59.get().getSlackWebhookUrl();
 
-      HttpHeaders headers = new HttpHeaders();
-      headers.setContentType(MediaType.APPLICATION_JSON);
-
-      HttpEntity<SlackMessage> request = new HttpEntity<>(slackMessage, headers);
+      restClient
+          .post()
+          .uri(webhookUrl)
+          .contentType(MediaType.APPLICATION_JSON)
+          .body(slackMessage)
+          .retrieve()
+          .toEntity(String.class);
 
-      String webhookUrl = challenge59.get().getSlackWebhookUrl();
-      restTemplate.postForEntity(webhookUrl, request, String.class);
       logger.info(
           "Successfully sent Slack notification for challenge completion: {}", challengeName);
 

src/test/java/org/owasp/wrongsecrets/ApiExceptionAdviceTest.java

@@ -0,0 +1,63 @@
+package org.owasp.wrongsecrets;
+
+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;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+import org.springframework.web.server.ResponseStatusException;
+
+/** Tests that {@link ApiExceptionAdvice} returns RFC 9457-style {@code ProblemDetail} payloads. */
+class ApiExceptionAdviceTest {
+
+  private MockMvc mvc;
+
+  @BeforeEach
+  void setUp() {
+    mvc =
+        MockMvcBuilders.standaloneSetup(new TestRestController())
+            .setControllerAdvice(new ApiExceptionAdvice())
+            .build();
+  }
+
+  @Test
+  void shouldReturnProblemDetailWithRfc9457FieldsForResponseStatusException() throws Exception {
+    mvc.perform(get("/test/not-found").accept(MediaType.APPLICATION_JSON))
+        .andExpect(status().isNotFound())
+        .andExpect(jsonPath("$.status").value(404))
+        .andExpect(jsonPath("$.title").exists())
+        .andExpect(jsonPath("$.detail").exists())
+        .andExpect(jsonPath("$.instance").exists());
+  }
+
+  @Test
+  void shouldReturnProblemDetailWithRfc9457FieldsForGenericException() throws Exception {
+    mvc.perform(get("/test/error").accept(MediaType.APPLICATION_JSON))
+        .andExpect(status().isInternalServerError())
+        .andExpect(jsonPath("$.status").value(500))
+        .andExpect(jsonPath("$.title").value("Internal Server Error"))
+        .andExpect(jsonPath("$.detail").exists())
+        .andExpect(jsonPath("$.instance").exists());
+  }
+
+  @RestController
+  static class TestRestController {
+
+    @GetMapping("/test/not-found")
+    public String notFound() {
+      throw new ResponseStatusException(HttpStatus.NOT_FOUND, "Resource not found");
+    }
+
+    @GetMapping("/test/error")
+    public String error() {
+      throw new RuntimeException("Unexpected failure");
+    }
+  }
+}