Use Spring Framework's NoOpResponseErrorHandler

See spring-projects/spring-framework#32750

Closes gh-41183

Author: snicoll

spring-boot-project/spring-boot-test/src/main/java/org/springframework/boot/test/web/client/TestRestTemplate.java

@@ -16,7 +16,6 @@
 
 package org.springframework.boot.test.web.client;
 
-import java.io.IOException;
 import java.net.URI;
 import java.security.KeyManagementException;
 import java.security.KeyStoreException;
@@ -57,10 +56,9 @@
 import org.springframework.http.RequestEntity.UriTemplateRequestEntity;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.client.ClientHttpRequestFactory;
-import org.springframework.http.client.ClientHttpResponse;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
 import org.springframework.util.Assert;
-import org.springframework.web.client.DefaultResponseErrorHandler;
+import org.springframework.web.client.NoOpResponseErrorHandler;
 import org.springframework.web.client.RequestCallback;
 import org.springframework.web.client.ResponseExtractor;
 import org.springframework.web.client.RestTemplate;
@@ -1077,12 +1075,4 @@ protected RequestConfig createRequestConfig() {
 
 	}
 
-	private static final class NoOpResponseErrorHandler extends DefaultResponseErrorHandler {
-
-		@Override
-		public void handleError(ClientHttpResponse response) throws IOException {
-		}
-
-	}
-
 }

spring-boot-project/spring-boot-test/src/test/java/org/springframework/boot/test/web/client/TestRestTemplateTests.java

@@ -45,6 +45,7 @@
 import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.util.ReflectionUtils;
 import org.springframework.util.ReflectionUtils.MethodCallback;
+import org.springframework.web.client.NoOpResponseErrorHandler;
 import org.springframework.web.client.ResponseErrorHandler;
 import org.springframework.web.client.RestOperations;
 import org.springframework.web.client.RestTemplate;
@@ -223,13 +224,12 @@ private Stream<Class<?>> getConverterClasses(TestRestTemplate testRestTemplate)
 	}
 
 	@Test
-	void withBasicAuthShouldUseNoOpErrorHandler() throws Exception {
+	void withBasicAuthShouldUseNoOpErrorHandler() {
 		TestRestTemplate originalTemplate = new TestRestTemplate("foo", "bar");
 		ResponseErrorHandler errorHandler = mock(ResponseErrorHandler.class);
 		originalTemplate.getRestTemplate().setErrorHandler(errorHandler);
 		TestRestTemplate basicAuthTemplate = originalTemplate.withBasicAuth("user", "password");
-		assertThat(basicAuthTemplate.getRestTemplate().getErrorHandler()).isInstanceOf(
-				Class.forName("org.springframework.boot.test.web.client.TestRestTemplate$NoOpResponseErrorHandler"));
+		assertThat(basicAuthTemplate.getRestTemplate().getErrorHandler()).isInstanceOf(NoOpResponseErrorHandler.class);
 	}
 
 	@Test