Refine null-safety in spring-test

See spring-projectsgh-32475

spring-test/src/main/java/org/springframework/mock/web/MockFilterConfig.java

@@ -97,6 +97,7 @@ public void addInitParameter(String name, String value) {
 	}
 
 	@Override
+	@Nullable
 	public String getInitParameter(String name) {
 		Assert.notNull(name, "Parameter name must not be null");
 		return this.initParameters.get(name);

spring-test/src/main/java/org/springframework/mock/web/MockHttpServletRequest.java

@@ -383,6 +383,7 @@ protected void checkActive() throws IllegalStateException {
 	// ---------------------------------------------------------------------
 
 	@Override
+	@Nullable
 	public Object getAttribute(String name) {
 		checkActive();
 		return this.attributes.get(name);
@@ -637,6 +638,7 @@ public Enumeration<String> getParameterNames() {
 	}
 
 	@Override
+	@Nullable
 	public String[] getParameterValues(String name) {
 		Assert.notNull(name, "Parameter name must not be null");
 		return this.parameters.get(name);

spring-test/src/main/java/org/springframework/mock/web/MockHttpSession.java

@@ -148,6 +148,7 @@ public int getMaxInactiveInterval() {
 	}
 
 	@Override
+	@Nullable
 	public Object getAttribute(String name) {
 		assertIsValid();
 		Assert.notNull(name, "Attribute name must not be null");

spring-test/src/main/java/org/springframework/mock/web/MockMultipartHttpServletRequest.java

@@ -96,6 +96,7 @@ public Iterator<String> getFileNames() {
 	}
 
 	@Override
+	@Nullable
 	public MultipartFile getFile(String name) {
 		return this.multipartFiles.getFirst(name);
 	}
@@ -117,6 +118,7 @@ public MultiValueMap<String, MultipartFile> getMultiFileMap() {
 	}
 
 	@Override
+	@Nullable
 	public String getMultipartContentType(String paramOrFileName) {
 		MultipartFile file = getFile(paramOrFileName);
 		if (file != null) {
@@ -154,6 +156,7 @@ public HttpHeaders getRequestHeaders() {
 	}
 
 	@Override
+	@Nullable
 	public HttpHeaders getMultipartHeaders(String paramOrFileName) {
 		MultipartFile file = getFile(paramOrFileName);
 		if (file != null) {

spring-test/src/main/java/org/springframework/mock/web/MockServletConfig.java

@@ -93,6 +93,7 @@ public void addInitParameter(String name, String value) {
 	}
 
 	@Override
+	@Nullable
 	public String getInitParameter(String name) {
 		Assert.notNull(name, "Parameter name must not be null");
 		return this.initParameters.get(name);

spring-test/src/main/java/org/springframework/mock/web/MockServletContext.java

@@ -223,6 +223,7 @@ public void registerContext(String contextPath, ServletContext context) {
 	}
 
 	@Override
+	@Nullable
 	public ServletContext getContext(String contextPath) {
 		if (this.contextPath.equals(contextPath)) {
 			return this;
@@ -375,6 +376,7 @@ public RequestDispatcher getRequestDispatcher(String path) {
 	}
 
 	@Override
+	@Nullable
 	public RequestDispatcher getNamedDispatcher(String path) {
 		return this.namedRequestDispatchers.get(path);
 	}
@@ -464,6 +466,7 @@ public String getServerInfo() {
 	}
 
 	@Override
+	@Nullable
 	public String getInitParameter(String name) {
 		Assert.notNull(name, "Parameter name must not be null");
 		return this.initParameters.get(name);

spring-test/src/main/java/org/springframework/mock/web/MockSessionCookieConfig.java

@@ -136,6 +136,7 @@ public void setAttribute(String name, String value) {
 	}
 
 	@Override
+	@Nullable
 	public String getAttribute(String name) {
 		return this.attributes.get(name);
 	}

spring-test/src/main/java/org/springframework/mock/web/reactive/function/server/MockServerRequest.java

@@ -569,6 +569,7 @@ public Optional<MediaType> contentType() {
 		}
 
 		@Override
+		@Nullable
 		public InetSocketAddress host() {
 			return delegate().getHost();
 		}

spring-test/src/main/java/org/springframework/test/context/ApplicationContextFailureProcessor.java

@@ -17,6 +17,7 @@
 package org.springframework.test.context;
 
 import org.springframework.context.ApplicationContext;
+import org.springframework.lang.Nullable;
 
 /**
  * Strategy for components that process failures related to application contexts
@@ -41,6 +42,6 @@ public interface ApplicationContextFailureProcessor {
 	 * @param context the application context that did not load successfully
 	 * @param exception the exception thrown while loading the application context
 	 */
-	void processLoadFailure(ApplicationContext context, Throwable exception);
+	void processLoadFailure(ApplicationContext context, @Nullable Throwable exception);
 
 }

spring-test/src/main/java/org/springframework/test/context/SmartContextLoader.java

@@ -17,7 +17,6 @@
 package org.springframework.test.context;
 
 import org.springframework.context.ApplicationContext;
-import org.springframework.lang.Nullable;
 
 /**
  * Strategy interface for loading an {@link ApplicationContext} for an integration
@@ -157,7 +156,7 @@ public interface SmartContextLoader extends ContextLoader {
 	 */
 	@Override
 	@SuppressWarnings("deprecation")
-	default String[] processLocations(Class<?> clazz, @Nullable String... locations) {
+	default String[] processLocations(Class<?> clazz, String... locations) {
 		throw new UnsupportedOperationException("""
 				SmartContextLoader does not support the ContextLoader SPI. \
 				Call processContextConfiguration(ContextConfigurationAttributes) instead.""");

spring-test/src/main/java/org/springframework/test/context/hint/TestContextRuntimeHints.java

@@ -26,6 +26,7 @@
 import org.springframework.aot.hint.RuntimeHintsRegistrar;
 import org.springframework.aot.hint.TypeHint;
 import org.springframework.aot.hint.TypeReference;
+import org.springframework.lang.Nullable;
 import org.springframework.util.ClassUtils;
 
 /**
@@ -39,7 +40,7 @@
 class TestContextRuntimeHints implements RuntimeHintsRegistrar {
 
 	@Override
-	public void registerHints(RuntimeHints runtimeHints, ClassLoader classLoader) {
+	public void registerHints(RuntimeHints runtimeHints, @Nullable ClassLoader classLoader) {
 		boolean servletPresent = ClassUtils.isPresent("jakarta.servlet.Servlet", classLoader);
 		boolean groovyPresent = ClassUtils.isPresent("groovy.lang.Closure", classLoader);
 

spring-test/src/main/java/org/springframework/test/context/support/DynamicValuesPropertySource.java

@@ -20,6 +20,7 @@
 import java.util.function.Supplier;
 
 import org.springframework.core.env.MapPropertySource;
+import org.springframework.lang.Nullable;
 import org.springframework.util.function.SupplierUtils;
 
 /**
@@ -38,6 +39,7 @@ class DynamicValuesPropertySource extends MapPropertySource {
 	}
 
 	@Override
+	@Nullable
 	public Object getProperty(String name) {
 		return SupplierUtils.resolve(super.getProperty(name));
 	}

spring-test/src/main/java/org/springframework/test/context/support/TestPropertySourceUtils.java

@@ -459,6 +459,7 @@ private static class SequencedProperties extends Properties {
 		private final LinkedHashMap<String, Object> map = new LinkedHashMap<>();
 
 		@Override
+		@Nullable
 		public Object put(Object key, Object value) {
 			if (key instanceof String str) {
 				return this.map.put(str, value);

spring-test/src/main/java/org/springframework/test/context/testng/AbstractTestNGSpringContextTests.java

@@ -198,6 +198,7 @@ protected void springTestContextAfterTestClass() throws Exception {
 	}
 
 
+	@Nullable
 	private Throwable getTestResultException(ITestResult testResult) {
 		Throwable testResultException = testResult.getThrowable();
 		if (testResultException instanceof InvocationTargetException) {

spring-test/src/main/java/org/springframework/test/context/transaction/TransactionalTestExecutionListener.java

@@ -155,6 +155,7 @@ public class TransactionalTestExecutionListener extends AbstractTestExecutionLis
 	protected final TransactionAttributeSource attributeSource = new AnnotationTransactionAttributeSource(false) {
 
 		@Override
+		@Nullable
 		protected TransactionAttribute findTransactionAttribute(Class<?> clazz) {
 			// @Transactional present in inheritance hierarchy?
 			TransactionAttribute result = super.findTransactionAttribute(clazz);

spring-test/src/main/java/org/springframework/test/web/client/response/ExecutingResponseCreator.java

@@ -21,6 +21,7 @@
 import org.springframework.http.client.ClientHttpRequest;
 import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.http.client.ClientHttpResponse;
+import org.springframework.lang.Nullable;
 import org.springframework.mock.http.client.MockClientHttpRequest;
 import org.springframework.test.web.client.ResponseCreator;
 import org.springframework.util.Assert;
@@ -59,7 +60,7 @@ public ExecutingResponseCreator(ClientHttpRequestFactory requestFactory) {
 
 
 	@Override
-	public ClientHttpResponse createResponse(ClientHttpRequest request) throws IOException {
+	public ClientHttpResponse createResponse(@Nullable ClientHttpRequest request) throws IOException {
 		Assert.state(request instanceof MockClientHttpRequest, "Expected a MockClientHttpRequest");
 		MockClientHttpRequest mockRequest = (MockClientHttpRequest) request;
 		ClientHttpRequest newRequest = this.requestFactory.createRequest(mockRequest.getURI(), mockRequest.getMethod());

spring-test/src/main/java/org/springframework/test/web/servlet/DefaultMvcResult.java

@@ -127,7 +127,7 @@ public FlashMap getFlashMap() {
 		return RequestContextUtils.getOutputFlashMap(this.mockRequest);
 	}
 
-	public void setAsyncResult(Object asyncResult) {
+	public void setAsyncResult(@Nullable Object asyncResult) {
 		this.asyncResult.set(asyncResult);
 	}
 

spring-test/src/main/java/org/springframework/test/web/servlet/TestDispatcherServlet.java

@@ -98,7 +98,7 @@ private void registerAsyncResultInterceptors(HttpServletRequest request) {
 		WebAsyncUtils.getAsyncManager(request).registerCallableInterceptor(KEY,
 				new CallableProcessingInterceptor() {
 					@Override
-					public <T> void postProcess(NativeWebRequest r, Callable<T> task, Object value) {
+					public <T> void postProcess(NativeWebRequest r, Callable<T> task, @Nullable Object value) {
 						// We got the result, must also wait for the dispatch
 						getMvcResult(request).setAsyncResult(value);
 					}
@@ -107,7 +107,7 @@ public <T> void postProcess(NativeWebRequest r, Callable<T> task, Object value)
 		WebAsyncUtils.getAsyncManager(request).registerDeferredResultInterceptor(KEY,
 				new DeferredResultProcessingInterceptor() {
 					@Override
-					public <T> void postProcess(NativeWebRequest r, DeferredResult<T> result, Object value) {
+					public <T> void postProcess(NativeWebRequest r, DeferredResult<T> result, @Nullable Object value) {
 						getMvcResult(request).setAsyncResult(value);
 					}
 				});
@@ -118,6 +118,7 @@ protected DefaultMvcResult getMvcResult(ServletRequest request) {
 	}
 
 	@Override
+	@Nullable
 	protected HandlerExecutionChain getHandler(HttpServletRequest request) throws Exception {
 		HandlerExecutionChain chain = super.getHandler(request);
 		if (chain != null) {
@@ -138,6 +139,7 @@ protected void render(ModelAndView mv, HttpServletRequest request, HttpServletRe
 	}
 
 	@Override
+	@Nullable
 	protected ModelAndView processHandlerException(HttpServletRequest request, HttpServletResponse response,
 			@Nullable Object handler, Exception ex) throws Exception {
 

spring-test/src/main/java/org/springframework/test/web/servlet/htmlunit/HtmlUnitRequestBuilder.java

@@ -451,6 +451,7 @@ public HtmlUnitMockHttpServletRequest(ServletContext servletContext, String meth
 		}
 
 		@Override
+		@Nullable
 		public HttpSession getSession(boolean create) {
 			HttpSession session = super.getSession(false);
 			if (session == null && create) {

spring-test/src/main/java/org/springframework/test/web/servlet/setup/StubWebApplicationContext.java

@@ -130,6 +130,7 @@ public long getStartupDate() {
 	}
 
 	@Override
+	@Nullable
 	public ApplicationContext getParent() {
 		return null;
 	}
@@ -218,11 +219,13 @@ public boolean isTypeMatch(String name, Class<?> typeToMatch) throws NoSuchBeanD
 	}
 
 	@Override
+	@Nullable
 	public Class<?> getType(String name) throws NoSuchBeanDefinitionException {
 		return this.beanFactory.getType(name);
 	}
 
 	@Override
+	@Nullable
 	public Class<?> getType(String name, boolean allowFactoryBeanInit) throws NoSuchBeanDefinitionException {
 		return this.beanFactory.getType(name, allowFactoryBeanInit);
 	}
@@ -337,6 +340,7 @@ public <A extends Annotation> Set<A> findAllAnnotationsOnBean(
 	//---------------------------------------------------------------------
 
 	@Override
+	@Nullable
 	public BeanFactory getParentBeanFactory() {
 		return null;
 	}
@@ -352,6 +356,7 @@ public boolean containsLocalBean(String name) {
 	//---------------------------------------------------------------------
 
 	@Override
+	@Nullable
 	public String getMessage(String code, @Nullable Object[] args, @Nullable String defaultMessage, Locale locale) {
 		return this.messageSource.getMessage(code, args, defaultMessage, locale);
 	}

spring-test/src/test/java/org/springframework/test/context/failures/TrackingApplicationContextFailureProcessor.java

@@ -21,6 +21,7 @@
 import java.util.List;
 
 import org.springframework.context.ApplicationContext;
+import org.springframework.lang.Nullable;
 import org.springframework.test.context.ApplicationContextFailureProcessor;
 
 /**
@@ -37,10 +38,10 @@ public class TrackingApplicationContextFailureProcessor implements ApplicationCo
 
 
 	@Override
-	public void processLoadFailure(ApplicationContext context, Throwable exception) {
+	public void processLoadFailure(ApplicationContext context, @Nullable Throwable exception) {
 		loadFailures.add(new LoadFailure(context, exception));
 	}
 
-	public record LoadFailure(ApplicationContext context, Throwable exception) {}
+	public record LoadFailure(ApplicationContext context, @Nullable Throwable exception) {}
 
 }