Polish Collection.toArray

Consistently use `StringUtils.toStringArray`, `ClassUtils.toClassArray`
or zero length when converting collections to arrays.

Fixes gh-12160

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/context/properties/ConfigurationPropertiesReportEndpointTests.java

@@ -35,6 +35,7 @@ import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.util.CollectionUtils;
+import org.springframework.util.StringUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -177,8 +178,7 @@ public class ConfigurationPropertiesReportEndpointTests {
 			ConfigurationPropertiesReportEndpoint endpoint = context
 					.getBean(ConfigurationPropertiesReportEndpoint.class);
 			if (!CollectionUtils.isEmpty(keysToSanitize)) {
-				endpoint.setKeysToSanitize(
-						keysToSanitize.toArray(new String[keysToSanitize.size()]));
+				endpoint.setKeysToSanitize(StringUtils.toStringArray(keysToSanitize));
 			}
 			properties.accept(context, endpoint.configurationProperties().getContexts()
 					.get(context.getId()));

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/annotation/EndpointDiscovererTests.java

@@ -264,7 +264,7 @@ public class EndpointDiscovererTests {
 		methods.add(findTestEndpointMethod("getOne", String.class));
 		methods.add(findTestEndpointMethod("update", String.class, String.class));
 		methods.add(findTestEndpointMethod("deleteOne", String.class));
-		return methods.toArray(new Method[] {});
+		return methods.toArray(new Method[0]);
 	}
 
 	private Method findTestEndpointMethod(String name, Class<?>... paramTypes) {

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/test/JerseyEndpointsRunner.java

@@ -47,6 +47,7 @@ import org.springframework.context.ApplicationContext;
 import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.util.ClassUtils;
 
 /**
  * {@link BlockJUnit4ClassRunner} for Jersey.
@@ -63,7 +64,7 @@ class JerseyEndpointsRunner extends AbstractWebEndpointRunner {
 	private static ConfigurableApplicationContext createContext(List<Class<?>> classes) {
 		AnnotationConfigServletWebServerApplicationContext context = new AnnotationConfigServletWebServerApplicationContext();
 		classes.add(JerseyEndpointConfiguration.class);
-		context.register(classes.toArray(new Class<?>[classes.size()]));
+		context.register(ClassUtils.toClassArray(classes));
 		context.refresh();
 		return context;
 	}

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/test/WebFluxEndpointsRunner.java

@@ -44,6 +44,7 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.http.MediaType;
 import org.springframework.http.server.reactive.HttpHandler;
+import org.springframework.util.ClassUtils;
 import org.springframework.web.cors.CorsConfiguration;
 import org.springframework.web.server.adapter.WebHttpHandlerBuilder;
 
@@ -62,7 +63,7 @@ class WebFluxEndpointsRunner extends AbstractWebEndpointRunner {
 	private static ConfigurableApplicationContext createContext(List<Class<?>> classes) {
 		AnnotationConfigReactiveWebServerApplicationContext context = new AnnotationConfigReactiveWebServerApplicationContext();
 		classes.add(WebFluxEndpointConfiguration.class);
-		context.register(classes.toArray(new Class<?>[classes.size()]));
+		context.register(ClassUtils.toClassArray(classes));
 		context.refresh();
 		return context;
 	}

spring-boot-project/spring-boot-actuator/src/test/java/org/springframework/boot/actuate/endpoint/web/test/WebMvcEndpointRunner.java

@@ -43,6 +43,7 @@ import org.springframework.context.ConfigurableApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.http.MediaType;
+import org.springframework.util.ClassUtils;
 import org.springframework.web.cors.CorsConfiguration;
 
 /**
@@ -60,7 +61,7 @@ class WebMvcEndpointRunner extends AbstractWebEndpointRunner {
 	private static ConfigurableApplicationContext createContext(List<Class<?>> classes) {
 		AnnotationConfigServletWebServerApplicationContext context = new AnnotationConfigServletWebServerApplicationContext();
 		classes.add(WebMvcEndpointConfiguration.class);
-		context.register(classes.toArray(new Class<?>[classes.size()]));
+		context.register(ClassUtils.toClassArray(classes));
 		context.refresh();
 		return context;
 	}