Revert "Polish some joining collectors"

See gh-14221

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/annotation/DiscoveredWebOperation.java

@@ -61,8 +61,8 @@ class DiscoveredWebOperation extends AbstractDiscoveredOperation implements WebO
 	}
 
 	private String getId(String endpointId, Method method) {
-		return Stream.of(method.getParameters()).filter(this::hasSelector)
-				.map(this::dashName).collect(Collectors.joining("", endpointId, ""));
+		return endpointId + Stream.of(method.getParameters()).filter(this::hasSelector)
+				.map(this::dashName).collect(Collectors.joining());
 	}
 
 	private boolean hasSelector(Parameter parameter) {

spring-boot-project/spring-boot-actuator/src/main/java/org/springframework/boot/actuate/endpoint/web/annotation/RequestPredicateFactory.java

@@ -62,8 +62,8 @@ class RequestPredicateFactory {
 	}
 
 	private String getPath(String rootPath, Method method) {
-		return Stream.of(method.getParameters()).filter(this::hasSelector)
-				.map(this::slashName).collect(Collectors.joining("", rootPath, ""));
+		return rootPath + Stream.of(method.getParameters()).filter(this::hasSelector)
+				.map(this::slashName).collect(Collectors.joining());
 	}
 
 	private boolean hasSelector(Parameter parameter) {