Remove redundant handling of a null exchange from WebFluxTags.uri()

Closes gh-14504

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/metrics/web/reactive/server/WebFluxTags.java

@@ -40,8 +40,6 @@ public final class WebFluxTags {
 
 	private static final Tag URI_ROOT = Tag.of("uri", "root");
 
-	private static final Tag URI_UNKNOWN = Tag.of("uri", "UNKNOWN");
-
 	private static final Tag EXCEPTION_NONE = Tag.of("exception", "None");
 
 	private WebFluxTags() {
@@ -80,7 +78,6 @@ public final class WebFluxTags {
 	 * @return the uri tag derived from the exchange
 	 */
 	public static Tag uri(ServerWebExchange exchange) {
-		if (exchange != null) {
 		PathPattern pathPattern = exchange
 				.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE);
 		if (pathPattern != null) {
@@ -99,8 +96,6 @@ public final class WebFluxTags {
 		}
 		return Tag.of("uri", path);
 	}
-		return URI_UNKNOWN;
-	}
 
 	/**
 	 * Creates an {@code exception} tag based on the {@link Class#getSimpleName() simple

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/metrics/web/reactive/server/WebFluxTagsTests.java

@@ -78,12 +78,6 @@ public class WebFluxTagsTests {
 		assertThat(tag.getValue()).isEqualTo("root");
 	}
 
-	@Test
-	public void uriTagIsUnknownWhenRequestIsNull() {
-		Tag tag = WebFluxTags.uri(null);
-		assertThat(tag.getValue()).isEqualTo("UNKNOWN");
-	}
-
 	@Test
 	public void methodTagToleratesNonStandardHttpMethods() {
 		ServerWebExchange exchange = mock(ServerWebExchange.class);