Merge branch '2.2.x'

Closes gh-19104

Author: snicoll

spring-boot-project/spring-boot-actuator-autoconfigure/src/main/java/org/springframework/boot/actuate/autoconfigure/web/servlet/ServletManagementChildContextConfiguration.java

@@ -190,7 +190,7 @@ public void customize(JettyServletWebServerFactory factory) {
 
 		private void customizeServer(Server server) {
 			RequestLog requestLog = server.getRequestLog();
-			if (requestLog != null && requestLog instanceof CustomRequestLog) {
+			if (requestLog instanceof CustomRequestLog) {
 				customizeRequestLog((CustomRequestLog) requestLog);
 			}
 		}

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

@@ -51,7 +51,7 @@ public class EndpointMediaTypes {
 	 * @since 2.2.0
 	 */
 	public EndpointMediaTypes(String... producedAndConsumed) {
-		this((producedAndConsumed != null) ? Arrays.asList(producedAndConsumed) : (List<String>) null);
+		this((producedAndConsumed != null) ? Arrays.asList(producedAndConsumed) : null);
 	}
 
 	/**

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/AutoConfigurationImportSelector.java

@@ -279,7 +279,7 @@ protected final <T> List<T> removeDuplicates(List<T> list) {
 
 	protected final List<String> asList(AnnotationAttributes attributes, String name) {
 		String[] value = attributes.getStringArray(name);
-		return Arrays.asList((value != null) ? value : new String[0]);
+		return Arrays.asList(value);
 	}
 
 	private void fireAutoConfigurationImportEvents(List<String> configurations, Set<String> exclusions) {

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/condition/OnResourceCondition.java

@@ -24,7 +24,6 @@
 import org.springframework.context.annotation.ConditionContext;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
-import org.springframework.core.io.DefaultResourceLoader;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.core.type.AnnotatedTypeMetadata;
 import org.springframework.util.Assert;
@@ -39,14 +38,11 @@
 @Order(Ordered.HIGHEST_PRECEDENCE + 20)
 class OnResourceCondition extends SpringBootCondition {
 
-	private final ResourceLoader defaultResourceLoader = new DefaultResourceLoader();
-
 	@Override
 	public ConditionOutcome getMatchOutcome(ConditionContext context, AnnotatedTypeMetadata metadata) {
 		MultiValueMap<String, Object> attributes = metadata
 				.getAllAnnotationAttributes(ConditionalOnResource.class.getName(), true);
-		ResourceLoader loader = (context.getResourceLoader() != null) ? context.getResourceLoader()
-				: this.defaultResourceLoader;
+		ResourceLoader loader = context.getResourceLoader();
 		List<String> locations = new ArrayList<>();
 		collectValues(locations, attributes.get("resources"));
 		Assert.isTrue(!locations.isEmpty(),