Merge pull request #15982 from nosan

* pr/15982:
  Polish "Fix request factory used with withBasicAuth"
  Fix request factory used with TestRestTemplate withBasicAuth

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

 /*
- * Copyright 2012-2018 the original author or authors.
+ * Copyright 2012-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,6 +26,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.function.Supplier;
 
 import org.apache.http.client.HttpClient;
 import org.apache.http.client.config.CookieSpecs;
@@ -38,6 +39,9 @@ import org.apache.http.impl.client.HttpClients;
 import org.apache.http.protocol.HttpContext;
 import org.apache.http.ssl.SSLContextBuilder;
 
+import org.springframework.beans.BeanInstantiationException;
+import org.springframework.beans.BeanUtils;
+import org.springframework.boot.web.client.ClientHttpRequestFactorySupplier;
 import org.springframework.boot.web.client.RestTemplateBuilder;
 import org.springframework.boot.web.client.RootUriTemplateHandler;
 import org.springframework.core.ParameterizedTypeReference;
@@ -1023,7 +1027,8 @@ public class TestRestTemplate {
 	/**
 	 * Creates a new {@code TestRestTemplate} with the same configuration as this one,
 	 * except that it will send basic authorization headers using the given
-	 * {@code username} and {@code password}.
+	 * {@code username} and {@code password}. The request factory used is a new instance
+	 * of the underlying {@link RestTemplate}'s request factory type (when possible).
 	 * @param username the username
 	 * @param password the password
 	 * @return the new template
@@ -1031,6 +1036,7 @@ public class TestRestTemplate {
 	 */
 	public TestRestTemplate withBasicAuth(String username, String password) {
 		RestTemplate restTemplate = new RestTemplateBuilder()
+				.requestFactory(getRequestFactorySupplier())
 				.messageConverters(getRestTemplate().getMessageConverters())
 				.interceptors(getRestTemplate().getInterceptors())
 				.uriTemplateHandler(getRestTemplate().getUriTemplateHandler()).build();
@@ -1041,6 +1047,18 @@ public class TestRestTemplate {
 		return testRestTemplate;
 	}
 
+	private Supplier<ClientHttpRequestFactory> getRequestFactorySupplier() {
+		return () -> {
+			try {
+				return BeanUtils
+						.instantiateClass(getRequestFactoryClass(getRestTemplate()));
+			}
+			catch (BeanInstantiationException ex) {
+				return new ClientHttpRequestFactorySupplier().get();
+			}
+		};
+	}
+
 	@SuppressWarnings({ "rawtypes", "unchecked" })
 	private RequestEntity<?> createRequestEntityWithRootAppliedUri(
 			RequestEntity<?> requestEntity) {

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

 /*
- * Copyright 2012-2018 the original author or authors.
+ * Copyright 2012-2019 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,6 +33,7 @@ import org.springframework.http.HttpEntity;
 import org.springframework.http.HttpMethod;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.RequestEntity;
+import org.springframework.http.client.ClientHttpRequest;
 import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.http.client.ClientHttpRequestInterceptor;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
@@ -93,6 +94,35 @@ public class TestRestTemplateTests {
 				.isInstanceOf(OkHttp3ClientHttpRequestFactory.class);
 	}
 
+	@Test
+	public void useTheSameRequestFactoryClassWithBasicAuth() {
+		OkHttp3ClientHttpRequestFactory customFactory = new OkHttp3ClientHttpRequestFactory();
+		RestTemplateBuilder builder = new RestTemplateBuilder()
+				.requestFactory(() -> customFactory);
+		TestRestTemplate testRestTemplate = new TestRestTemplate(builder)
+				.withBasicAuth("test", "test");
+		RestTemplate restTemplate = testRestTemplate.getRestTemplate();
+		Object requestFactory = ReflectionTestUtils
+				.getField(restTemplate.getRequestFactory(), "requestFactory");
+		assertThat(requestFactory).isNotEqualTo(customFactory)
+				.hasSameClassAs(customFactory);
+	}
+
+	@Test
+	public void withBasicAuthWhenRequestFactoryTypeCannotBeInstantiatedShouldFallback() {
+		TestClientHttpRequestFactory customFactory = new TestClientHttpRequestFactory(
+				"my-request-factory");
+		RestTemplateBuilder builder = new RestTemplateBuilder()
+				.requestFactory(() -> customFactory);
+		TestRestTemplate testRestTemplate = new TestRestTemplate(builder)
+				.withBasicAuth("test", "test");
+		RestTemplate restTemplate = testRestTemplate.getRestTemplate();
+		Object requestFactory = ReflectionTestUtils
+				.getField(restTemplate.getRequestFactory(), "requestFactory");
+		assertThat(requestFactory).isNotEqualTo(customFactory)
+				.isInstanceOf(CustomHttpComponentsClientHttpRequestFactory.class);
+	}
+
 	@Test
 	public void getRootUriRootUriSetViaRestTemplateBuilder() {
 		String rootUri = "http://example.com";
@@ -383,4 +413,17 @@ public class TestRestTemplateTests {
 
 	}
 
+	static class TestClientHttpRequestFactory implements ClientHttpRequestFactory {
+
+		TestClientHttpRequestFactory(String value) {
+		}
+
+		@Override
+		public ClientHttpRequest createRequest(URI uri, HttpMethod httpMethod)
+				throws IOException {
+			return null;
+		}
+
+	}
+
 }