Perform NullAway build-time checks in spring-webmvc

See gh-32475

gradle/spring-module.gradle

@@ -118,7 +118,7 @@ tasks.withType(JavaCompile).configureEach {
     	disableAllChecks = true
         option("NullAway:CustomContractAnnotations", "org.springframework.lang.Contract")
         option("NullAway:AnnotatedPackages", "org.springframework.core,org.springframework.expression," +
-        		"org.springframework.web.reactive")
+        		"org.springframework.web.reactive,org.springframework.web.servlet")
         option("NullAway:UnannotatedSubPackages", "org.springframework.instrument,org.springframework.context.index," +
 				"org.springframework.asm,org.springframework.cglib,org.springframework.objenesis," +
 				"org.springframework.javapoet,org.springframework.aot.nativex.substitution")

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/ResourceChainRegistration.java

@@ -64,6 +64,7 @@ public class ResourceChainRegistration {
 		this(cacheResources, (cacheResources ? new ConcurrentMapCache(DEFAULT_CACHE_NAME) : null));
 	}
 
+	@SuppressWarnings("NullAway")
 	public ResourceChainRegistration(boolean cacheResources, @Nullable Cache cache) {
 		Assert.isTrue(!cacheResources || cache != null, "'cache' is required when cacheResources=true");
 		if (cacheResources) {

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/AbstractHandlerMethodMapping.java

@@ -442,6 +442,7 @@ public abstract class AbstractHandlerMethodMapping<T> extends AbstractHandlerMap
 		}
 	}
 
+	@SuppressWarnings("NullAway")
 	private void addMatchingMappings(Collection<T> mappings, List<Match> matches, HttpServletRequest request) {
 		for (T mapping : mappings) {
 			T match = getMatchingMapping(mapping, request);

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/AbstractUrlHandlerMapping.java

@@ -186,6 +186,7 @@ public abstract class AbstractUrlHandlerMapping extends AbstractHandlerMapping i
 	 * @since 5.3
 	 */
 	@Nullable
+	@SuppressWarnings("NullAway")
 	protected Object lookupHandler(
 			RequestPath path, String lookupPath, HttpServletRequest request) throws Exception {
 

spring-webmvc/src/main/java/org/springframework/web/servlet/handler/RequestMatchResult.java

@@ -94,7 +94,7 @@ public class RequestMatchResult {
 	 * {@link PathMatcher#extractUriTemplateVariables}.
 	 * @return a map with URI template variables
 	 */
-	@SuppressWarnings("ConstantConditions")
+	@SuppressWarnings({"ConstantConditions", "NullAway"})
 	public Map<String, String> extractUriTemplateVariables() {
 		return (this.pathPattern != null ?
 				this.pathPattern.matchAndExtract(this.lookupPathContainer).getUriVariables() :

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/RequestMappingInfo.java

@@ -490,7 +490,7 @@ public final class RequestMappingInfo implements RequestCondition<RequestMapping
 		return this.hashCode;
 	}
 
-	@SuppressWarnings("ConstantConditions")
+	@SuppressWarnings({"ConstantConditions", "NullAway"})
 	private static int calculateHashCode(
 			@Nullable PathPatternsRequestCondition pathPatterns, @Nullable PatternsRequestCondition patterns,
 			RequestMethodsRequestCondition methods, ParamsRequestCondition params, HeadersRequestCondition headers,

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/method/annotation/ServletInvocableHandlerMethod.java

@@ -215,6 +215,7 @@ public class ServletInvocableHandlerMethod extends InvocableHandlerMethod {
 
 		private final MethodParameter returnType;
 
+		@SuppressWarnings("NullAway")
 		public ConcurrentResultHandlerMethod(@Nullable Object result, ConcurrentResultMethodParameter returnType) {
 			super((Callable<Object>) () -> {
 				if (result instanceof Exception exception) {

spring-webmvc/src/main/java/org/springframework/web/servlet/resource/ResourceUrlProvider.java

@@ -219,6 +219,7 @@ public class ResourceUrlProvider implements ApplicationListener<ContextRefreshed
 	 * @return the resolved public URL path, or {@code null} if unresolved
 	 */
 	@Nullable
+	@SuppressWarnings("NullAway")
 	public final String getForLookupPath(String lookupPath) {
 		// Clean duplicate slashes or pathWithinPattern won't match lookupPath
 		String previous;

spring-webmvc/src/main/java/org/springframework/web/servlet/view/RedirectView.java

@@ -328,11 +328,11 @@ public class RedirectView extends AbstractUrlBasedView implements SmartView {
 		String url = getUrl();
 		Assert.state(url != null, "'url' not set");
 
-		if (this.contextRelative && getUrl().startsWith("/")) {
+		if (this.contextRelative && url.startsWith("/")) {
 			// Do not apply context path to relative URLs.
 			targetUrl.append(getContextPath(request));
 		}
-		targetUrl.append(getUrl());
+		targetUrl.append(url);
 
 		String enc = this.encodingScheme;
 		if (enc == null) {