Drop custom CustomHttpComponentsClientHttpRequestFactory

Replace `CustomHttpComponentsClientHttpRequestFactory` with
`HttpComponentsClientHttpRequestFactoryBuilder` to reduce the amount
of duplicated logic.

Closes gh-43422

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

@@ -25,6 +25,8 @@ import java.time.Duration;
 import java.util.Map;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
+import java.util.function.Consumer;
+import java.util.function.Function;
 import java.util.function.UnaryOperator;
 
 import javax.net.ssl.SSLContext;
@@ -45,8 +47,11 @@ import org.apache.hc.core5.http.ssl.TLS;
 import org.apache.hc.core5.ssl.SSLContextBuilder;
 import org.apache.hc.core5.ssl.TrustStrategy;
 
+import org.springframework.boot.http.client.ClientHttpRequestFactoryBuilder;
 import org.springframework.boot.http.client.ClientHttpRequestFactorySettings;
 import org.springframework.boot.http.client.ClientHttpRequestFactorySettings.Redirects;
+import org.springframework.boot.http.client.HttpComponentsClientHttpRequestFactoryBuilder;
+import org.springframework.boot.ssl.SslBundle;
 import org.springframework.boot.web.client.RestTemplateBuilder;
 import org.springframework.boot.web.client.RootUriTemplateHandler;
 import org.springframework.core.ParameterizedTypeReference;
@@ -56,7 +61,6 @@ import org.springframework.http.HttpMethod;
 import org.springframework.http.RequestEntity;
 import org.springframework.http.RequestEntity.UriTemplateRequestEntity;
 import org.springframework.http.ResponseEntity;
-import org.springframework.http.client.ClientHttpRequestFactory;
 import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;
@@ -155,14 +159,12 @@ public class TestRestTemplate {
 	private static RestTemplateBuilder createInitialBuilder(RestTemplateBuilder builder, String username,
 			String password, HttpClientOption... httpClientOptions) {
 		Assert.notNull(builder, "'builder' must not be null");
-		if (httpClientOptions != null) {
-			ClientHttpRequestFactory requestFactory = builder.buildRequestFactory();
-			if (requestFactory instanceof HttpComponentsClientHttpRequestFactory) {
-				builder = builder.redirects(HttpClientOption.ENABLE_REDIRECTS.isPresent(httpClientOptions)
-						? Redirects.FOLLOW : Redirects.DONT_FOLLOW);
-				builder = builder.requestFactoryBuilder(
-						(settings) -> new CustomHttpComponentsClientHttpRequestFactory(httpClientOptions, settings));
-			}
+		ClientHttpRequestFactoryBuilder<?> requestFactoryBuilder = builder.requestFactoryBuilder();
+		if (requestFactoryBuilder instanceof HttpComponentsClientHttpRequestFactoryBuilder) {
+			builder = builder.requestFactoryBuilder(applyHttpClientOptions(
+					(HttpComponentsClientHttpRequestFactoryBuilder) requestFactoryBuilder, httpClientOptions));
+			builder = builder.redirects(HttpClientOption.ENABLE_REDIRECTS.isPresent(httpClientOptions)
+					? Redirects.FOLLOW : Redirects.DONT_FOLLOW);
 		}
 		if (username != null || password != null) {
 			builder = builder.basicAuthentication(username, password);
@@ -170,6 +172,16 @@ public class TestRestTemplate {
 		return builder;
 	}
 
+	private static HttpComponentsClientHttpRequestFactoryBuilder applyHttpClientOptions(
+			HttpComponentsClientHttpRequestFactoryBuilder builder, HttpClientOption[] httpClientOptions) {
+		builder = builder.withDefaultRequestConfigCustomizer(
+				new CookieSpecCustomizer(HttpClientOption.ENABLE_COOKIES.isPresent(httpClientOptions)));
+		if (HttpClientOption.SSL.isPresent(httpClientOptions)) {
+			builder = builder.withTlsSocketStrategyFactory(new SelfSignedTlsSocketStrategyFactory());
+		}
+		return builder;
+	}
+
 	/**
 	 * Configure the {@link UriTemplateHandler} to use to expand URI templates. By default
 	 * the {@link DefaultUriBuilderFactory} is used which relies on Spring's URI template
@@ -1049,7 +1061,10 @@ public class TestRestTemplate {
 
 	/**
 	 * {@link HttpComponentsClientHttpRequestFactory} to apply customizations.
+	 *
+	 * @deprecated since 3.5.0 for removal in 4.0.0
 	 */
+	@Deprecated
 	protected static class CustomHttpComponentsClientHttpRequestFactory extends HttpComponentsClientHttpRequestFactory {
 
 		private final String cookieSpec;
@@ -1142,6 +1157,31 @@ public class TestRestTemplate {
 
 	}
 
+	/**
+	 * Factory used to create a {@link TlsSocketStrategy} supporting self-signed
+	 * certificates.
+	 */
+	private static class SelfSignedTlsSocketStrategyFactory implements Function<SslBundle, TlsSocketStrategy> {
+
+		private static final String[] SUPPORTED_PROTOCOLS = { TLS.V_1_3.getId(), TLS.V_1_2.getId() };
+
+		@Override
+		public TlsSocketStrategy apply(SslBundle sslBundle) {
+			try {
+				TrustSelfSignedStrategy trustStrategy = new TrustSelfSignedStrategy();
+				SSLContext sslContext = new SSLContextBuilder().loadTrustMaterial(null, trustStrategy).build();
+				return new DefaultClientTlsStrategy(sslContext, SUPPORTED_PROTOCOLS, null, null, null);
+			}
+			catch (KeyManagementException | NoSuchAlgorithmException | KeyStoreException ex) {
+				throw new IllegalStateException(ex);
+			}
+		}
+
+	}
+
+	/**
+	 * {@link TrustStrategy} supporting self-signed certificates.
+	 */
 	private static final class TrustSelfSignedStrategy implements TrustStrategy {
 
 		@Override
@@ -1151,4 +1191,19 @@ public class TestRestTemplate {
 
 	}
 
+	private static class CookieSpecCustomizer implements Consumer<RequestConfig.Builder> {
+
+		private final boolean enableCookies;
+
+		CookieSpecCustomizer(boolean enableCookies) {
+			this.enableCookies = enableCookies;
+		}
+
+		@Override
+		public void accept(RequestConfig.Builder builder) {
+			builder.setCookieSpec(this.enableCookies ? StandardCookieSpec.STRICT : StandardCookieSpec.IGNORE);
+		}
+
+	}
+
 }

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 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.
@@ -26,12 +26,15 @@ import java.util.Base64;
 import java.util.stream.Stream;
 
 import org.apache.hc.client5.http.config.RequestConfig;
+import org.apache.hc.client5.http.impl.DefaultRedirectStrategy;
+import org.apache.hc.client5.http.impl.classic.RedirectExec;
+import org.apache.hc.client5.http.protocol.RedirectStrategy;
+import org.assertj.core.extractor.Extractors;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.http.client.ClientHttpRequestFactoryBuilder;
 import org.springframework.boot.http.client.ClientHttpRequestFactorySettings;
 import org.springframework.boot.http.client.ClientHttpRequestFactorySettings.Redirects;
-import org.springframework.boot.test.web.client.TestRestTemplate.CustomHttpComponentsClientHttpRequestFactory;
 import org.springframework.boot.test.web.client.TestRestTemplate.HttpClientOption;
 import org.springframework.boot.web.client.RestTemplateBuilder;
 import org.springframework.core.ParameterizedTypeReference;
@@ -137,6 +140,7 @@ class TestRestTemplateTests {
 	}
 
 	@Test
+	@SuppressWarnings("removal")
 	void options() {
 		RequestConfig config = getRequestConfig(
 				new TestRestTemplate(HttpClientOption.ENABLE_REDIRECTS, HttpClientOption.ENABLE_COOKIES));
@@ -155,25 +159,29 @@ class TestRestTemplateTests {
 	}
 
 	@Test
+	@SuppressWarnings("removal")
 	void httpComponentsAreBuiltConsideringSettingsInRestTemplateBuilder() {
 		RestTemplateBuilder builder = new RestTemplateBuilder()
 			.requestFactoryBuilder(ClientHttpRequestFactoryBuilder.httpComponents());
-		assertThat(getRequestConfig((RestTemplateBuilder) null).isRedirectsEnabled()).isFalse();
-		assertThat(getRequestConfig(null, HttpClientOption.ENABLE_REDIRECTS).isRedirectsEnabled()).isTrue();
-		assertThat(getRequestConfig(builder).isRedirectsEnabled()).isFalse();
-		assertThat(getRequestConfig(builder, HttpClientOption.ENABLE_REDIRECTS).isRedirectsEnabled()).isTrue();
-		assertThat(getRequestConfig(builder.redirects(Redirects.DONT_FOLLOW)).isRedirectsEnabled()).isFalse();
-		assertThat(getRequestConfig(builder.redirects(Redirects.DONT_FOLLOW), HttpClientOption.ENABLE_REDIRECTS)
-			.isRedirectsEnabled()).isTrue();
+		assertThat(getRedirectStrategy((RestTemplateBuilder) null)).matches(this::isDontFollowStrategy);
+		assertThat(getRedirectStrategy(null, HttpClientOption.ENABLE_REDIRECTS)).matches(this::isFollowStrategy);
+		assertThat(getRedirectStrategy(builder)).matches(this::isDontFollowStrategy);
+		assertThat(getRedirectStrategy(builder, HttpClientOption.ENABLE_REDIRECTS)).matches(this::isFollowStrategy);
+		assertThat(getRedirectStrategy(builder.redirects(Redirects.DONT_FOLLOW))).matches(this::isDontFollowStrategy);
+		assertThat(getRedirectStrategy(builder.redirects(Redirects.DONT_FOLLOW), HttpClientOption.ENABLE_REDIRECTS))
+			.matches(this::isFollowStrategy);
 	}
 
 	@Test
 	void withRequestFactorySettingsRedirectsForHttpComponents() {
 		TestRestTemplate template = new TestRestTemplate();
-		assertThat(getRequestConfig(template).isRedirectsEnabled()).isFalse();
-		assertThat(getRequestConfig(template
-			.withRequestFactorySettings(ClientHttpRequestFactorySettings.defaults().withRedirects(Redirects.FOLLOW)))
-			.isRedirectsEnabled()).isTrue();
+		assertThat(getRedirectStrategy(template)).matches(this::isDontFollowStrategy);
+		assertThat(getRedirectStrategy(template
+			.withRequestFactorySettings(ClientHttpRequestFactorySettings.defaults().withRedirects(Redirects.FOLLOW))))
+			.matches(this::isFollowStrategy);
+		assertThat(getRedirectStrategy(template.withRequestFactorySettings(
+				ClientHttpRequestFactorySettings.defaults().withRedirects(Redirects.DONT_FOLLOW))))
+			.matches(this::isDontFollowStrategy);
 	}
 
 	@Test
@@ -196,17 +204,36 @@ class TestRestTemplateTests {
 			.followRedirects()).isEqualTo(Redirect.NEVER);
 	}
 
-	private RequestConfig getRequestConfig(RestTemplateBuilder builder, HttpClientOption... httpClientOptions) {
+	private RequestConfig getRequestConfig(TestRestTemplate template) {
+		ClientHttpRequestFactory requestFactory = template.getRestTemplate().getRequestFactory();
+		return (RequestConfig) Extractors.byName("httpClient.defaultConfig").apply(requestFactory);
+	}
+
+	private RedirectStrategy getRedirectStrategy(RestTemplateBuilder builder, HttpClientOption... httpClientOptions) {
 		builder = (builder != null) ? builder : new RestTemplateBuilder();
 		TestRestTemplate template = new TestRestTemplate(builder, null, null, httpClientOptions);
-		return getRequestConfig(template);
+		return getRedirectStrategy(template);
 	}
 
-	private RequestConfig getRequestConfig(TestRestTemplate template) {
-		CustomHttpComponentsClientHttpRequestFactory factory = (CustomHttpComponentsClientHttpRequestFactory) template
-			.getRestTemplate()
-			.getRequestFactory();
-		return factory.createRequestConfig();
+	private RedirectStrategy getRedirectStrategy(TestRestTemplate template) {
+		ClientHttpRequestFactory requestFactory = template.getRestTemplate().getRequestFactory();
+		Object chain = Extractors.byName("httpClient.execChain").apply(requestFactory);
+		while (chain != null) {
+			Object handler = Extractors.byName("handler").apply(chain);
+			if (handler instanceof RedirectExec) {
+				return (RedirectStrategy) Extractors.byName("redirectStrategy").apply(handler);
+			}
+			chain = Extractors.byName("next").apply(chain);
+		}
+		return null;
+	}
+
+	private boolean isFollowStrategy(RedirectStrategy redirectStrategy) {
+		return redirectStrategy instanceof DefaultRedirectStrategy;
+	}
+
+	private boolean isDontFollowStrategy(RedirectStrategy redirectStrategy) {
+		return redirectStrategy.getClass().getName().contains("NoFollow");
 	}
 
 	private HttpClient getJdkHttpClient(TestRestTemplate template) {

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

@@ -750,11 +750,22 @@ public class RestTemplateBuilder {
 	 * @since 2.2.0
 	 */
 	public ClientHttpRequestFactory buildRequestFactory() {
+		ClientHttpRequestFactoryBuilder<?> requestFactoryBuilder = requestFactoryBuilder();
+		return (requestFactoryBuilder != null) ? requestFactoryBuilder.build(this.requestFactorySettings) : null;
+	}
+
+	/**
+	 * Return a {@link ClientHttpRequestFactoryBuilder} instance using the settings of
+	 * this builder.
+	 * @return a {@link ClientHttpRequestFactoryBuilder} or {@code null}
+	 * @since 3.5.0
+	 */
+	public ClientHttpRequestFactoryBuilder<?> requestFactoryBuilder() {
 		if (this.requestFactoryBuilder != null) {
-			return this.requestFactoryBuilder.build(this.requestFactorySettings);
+			return this.requestFactoryBuilder;
 		}
 		if (this.detectRequestFactory) {
-			return ClientHttpRequestFactoryBuilder.detect().build(this.requestFactorySettings);
+			return ClientHttpRequestFactoryBuilder.detect();
 		}
 		return null;
 	}