Refine null-safety in DestinationPatternsMessageCondition

See gh-28797

Author: sdeleuze

spring-messaging/src/main/java/org/springframework/messaging/handler/DestinationPatternsMessageCondition.java

@@ -71,7 +71,7 @@ public DestinationPatternsMessageCondition(String... patterns) {
 	 * @param patterns the URL patterns to match to, or if 0 then always match
 	 * @param matcher the {@code PathMatcher} to use
 	 */
-	public DestinationPatternsMessageCondition(@Nullable String[] patterns, @Nullable PathMatcher matcher) {
+	public DestinationPatternsMessageCondition(String[] patterns, @Nullable PathMatcher matcher) {
 		this(patterns, new SimpleRouteMatcher(matcher != null ? matcher : new AntPathMatcher()));
 	}
 
@@ -81,14 +81,13 @@ public DestinationPatternsMessageCondition(@Nullable String[] patterns, @Nullabl
 	 * @param routeMatcher the {@code RouteMatcher} to use
 	 * @since 5.2
 	 */
-	public DestinationPatternsMessageCondition(@Nullable String[] patterns, RouteMatcher routeMatcher) {
+	public DestinationPatternsMessageCondition(String[] patterns, RouteMatcher routeMatcher) {
 		this(Collections.unmodifiableSet(prependLeadingSlash(patterns, routeMatcher)), routeMatcher);
 	}
 
-	@SuppressWarnings("NullAway") // https://github.com/uber/NullAway/issues/1125
-	private static Set<@Nullable String> prependLeadingSlash(@Nullable String[] patterns, RouteMatcher routeMatcher) {
+	private static Set<String> prependLeadingSlash(String[] patterns, RouteMatcher routeMatcher) {
 		boolean slashSeparator = routeMatcher.combine("a", "a").equals("a/a");
-		Set<@Nullable String> result = CollectionUtils.newLinkedHashSet(patterns.length);
+		Set<String> result = CollectionUtils.newLinkedHashSet(patterns.length);
 		for (String pattern : patterns) {
 			if (slashSeparator && StringUtils.hasLength(pattern) && !pattern.startsWith("/")) {
 				pattern = "/" + pattern;

spring-messaging/src/main/java/org/springframework/messaging/simp/annotation/support/SimpAnnotationMethodMessageHandler.java

@@ -23,6 +23,7 @@
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 
 import org.apache.commons.logging.Log;
@@ -422,13 +423,13 @@ protected boolean isHandler(Class<?> beanType) {
 	}
 
 	private SimpMessageMappingInfo createMessageMappingCondition(String[] destinations) {
-		@Nullable String[] resolvedDestinations = resolveEmbeddedValuesInDestinations(destinations);
+		String[] resolvedDestinations = resolveEmbeddedValuesInDestinations(destinations);
 		return new SimpMessageMappingInfo(SimpMessageTypeMessageCondition.MESSAGE,
 				new DestinationPatternsMessageCondition(resolvedDestinations, this.pathMatcher));
 	}
 
 	private SimpMessageMappingInfo createSubscribeMappingCondition(String[] destinations) {
-		@Nullable String[] resolvedDestinations = resolveEmbeddedValuesInDestinations(destinations);
+		String[] resolvedDestinations = resolveEmbeddedValuesInDestinations(destinations);
 		return new SimpMessageMappingInfo(SimpMessageTypeMessageCondition.SUBSCRIBE,
 				new DestinationPatternsMessageCondition(resolvedDestinations, this.pathMatcher));
 	}
@@ -438,13 +439,13 @@ private SimpMessageMappingInfo createSubscribeMappingCondition(String[] destinat
 	 * @return a new array with updated destinations
 	 * @since 4.2
 	 */
-	protected @Nullable String[] resolveEmbeddedValuesInDestinations(String[] destinations) {
+	protected String[] resolveEmbeddedValuesInDestinations(String[] destinations) {
 		if (this.valueResolver == null) {
 			return destinations;
 		}
-		@Nullable String[] result = new String[destinations.length];
+		String[] result = new String[destinations.length];
 		for (int i = 0; i < destinations.length; i++) {
-			result[i] = this.valueResolver.resolveStringValue(destinations[i]);
+			result[i] = Objects.requireNonNull(this.valueResolver.resolveStringValue(destinations[i]));
 		}
 		return result;
 	}