okhttp supports custom protocols

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/FeignAutoConfiguration.java

@@ -41,6 +41,7 @@ import feign.hc5.ApacheHttp5Client;
 import feign.okhttp.OkHttpClient;
 import jakarta.annotation.PreDestroy;
 import okhttp3.ConnectionPool;
+import okhttp3.Protocol;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
@@ -92,6 +93,7 @@ import org.springframework.util.ClassUtils;
  * @author Sam Kruglov
  * @author Wojciech Mąka
  * @author Dangzhicairang(小水牛)
+ * @author changjin wei(魏昌进)
  */
 @Configuration(proxyBeanMethods = false)
 @ConditionalOnClass(Feign.class)
@@ -259,11 +261,13 @@ public class FeignAutoConfiguration {
 			int connectTimeout = httpClientProperties.getConnectionTimeout();
 			boolean disableSslValidation = httpClientProperties.isDisableSslValidation();
 			Duration readTimeout = httpClientProperties.getOkHttp().getReadTimeout();
+			List<Protocol> protocols = httpClientProperties.getOkHttp().getProtocols();
 			if (disableSslValidation) {
 				disableSsl(builder);
 			}
 			this.okHttpClient = builder.connectTimeout(connectTimeout, TimeUnit.MILLISECONDS)
-					.followRedirects(followRedirects).readTimeout(readTimeout).connectionPool(connectionPool).build();
+					.followRedirects(followRedirects).readTimeout(readTimeout).connectionPool(connectionPool)
+					.protocols(protocols).build();
 			return this.okHttpClient;
 		}
 

spring-cloud-openfeign-core/src/main/java/org/springframework/cloud/openfeign/support/FeignHttpClientProperties.java

@@ -17,9 +17,11 @@
 package org.springframework.cloud.openfeign.support;
 
 import java.time.Duration;
+import java.util.List;
 import java.util.concurrent.TimeUnit;
 
 import feign.okhttp.OkHttpClient;
+import okhttp3.Protocol;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
@@ -336,6 +338,11 @@ public class FeignHttpClientProperties {
 		 */
 		private Duration readTimeout = Duration.ofSeconds(60);
 
+		/**
+		 * Configure the protocols used by this client to communicate with remote servers.
+		 */
+		private List<Protocol> protocols = List.of(Protocol.HTTP_2, Protocol.HTTP_1_1);
+
 		public Duration getReadTimeout() {
 			return readTimeout;
 		}
@@ -344,6 +351,14 @@ public class FeignHttpClientProperties {
 			this.readTimeout = readTimeout;
 		}
 
+		public List<Protocol> getProtocols() {
+			return protocols;
+		}
+
+		public void setProtocols(List<Protocol> protocols) {
+			this.protocols = protocols;
+		}
+
 	}
 
 }

spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/FeignOkHttpConfigurationTests.java

@@ -17,10 +17,12 @@
 package org.springframework.cloud.openfeign;
 
 import java.lang.reflect.Field;
+import java.util.List;
 
 import javax.net.ssl.HostnameVerifier;
 
 import okhttp3.OkHttpClient;
+import okhttp3.Protocol;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
@@ -34,6 +36,7 @@ import static org.assertj.core.api.Assertions.assertThat;
 
 /**
  * @author Ryan Baxter
+ * @author changjin wei(魏昌进)
  */
 class FeignOkHttpConfigurationTests {
 
@@ -45,7 +48,8 @@ class FeignOkHttpConfigurationTests {
 				.properties("debug=true", "spring.cloud.openfeign.httpclient.disableSslValidation=true",
 						"spring.cloud.openfeign.okhttp.enabled=true",
 						"spring.cloud.openfeign.httpclient.hc5.enabled=false",
-						"spring.cloud.openfeign.httpclient.okhttp.read-timeout=9s")
+						"spring.cloud.openfeign.httpclient.okhttp.read-timeout=9s",
+						"spring.cloud.openfeign.httpclient.okhttp.protocols=H2_PRIOR_KNOWLEDGE")
 				.web(WebApplicationType.NONE).sources(FeignAutoConfiguration.class).run();
 	}
 
@@ -71,6 +75,13 @@ class FeignOkHttpConfigurationTests {
 		assertThat(httpClient.readTimeoutMillis()).isEqualTo(9000);
 	}
 
+	@Test
+	void shouldProtocols() {
+		OkHttpClient httpClient = context.getBean(OkHttpClient.class);
+
+		assertThat(httpClient.protocols()).isEqualTo(List.of(Protocol.H2_PRIOR_KNOWLEDGE));
+	}
+
 	protected Object getField(Object target, String name) {
 		Field field = ReflectionUtils.findField(target.getClass(), name);
 		ReflectionUtils.makeAccessible(field);

spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/protocol/Application.java

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2013-2023 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.openfeign.protocol;
+
+import jakarta.servlet.http.HttpServletRequest;
+
+import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
+import org.springframework.boot.test.web.server.LocalServerPort;
+import org.springframework.cloud.client.DefaultServiceInstance;
+import org.springframework.cloud.loadbalancer.annotation.LoadBalancerClient;
+import org.springframework.cloud.loadbalancer.annotation.LoadBalancerClients;
+import org.springframework.cloud.loadbalancer.core.ServiceInstanceListSupplier;
+import org.springframework.cloud.loadbalancer.support.ServiceInstanceListSuppliers;
+import org.springframework.cloud.openfeign.EnableFeignClients;
+import org.springframework.cloud.openfeign.FeignClient;
+import org.springframework.cloud.openfeign.test.NoSecurityConfiguration;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Import;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+/**
+ * @author changjin wei(魏昌进)
+ */
+public class Application {
+
+	@FeignClient("localapp1")
+	protected interface ProtocolClient {
+
+		@GetMapping("/protocol")
+		String getProtocol();
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	@EnableAutoConfiguration
+	@RestController
+	@EnableFeignClients(clients = { ProtocolClient.class })
+	@LoadBalancerClients({ @LoadBalancerClient(name = "localapp1", configuration = LocalClientConfiguration.class) })
+	@Import(NoSecurityConfiguration.class)
+	protected static class ProtocolController {
+
+		@GetMapping("/protocol")
+		public String getProtocol(HttpServletRequest request) {
+			return request.getProtocol();
+		}
+
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class LocalClientConfiguration {
+
+		@LocalServerPort
+		private int port = 0;
+
+		@Bean
+		public ServiceInstanceListSupplier staticServiceInstanceListSupplier() {
+			return ServiceInstanceListSuppliers.from("local",
+					new DefaultServiceInstance("local-1", "local", "localhost", port, false));
+		}
+
+	}
+
+}

spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/protocol/FeignOkProtocolsTests.java

@@ -0,0 +1,61 @@
+/*
+ * Copyright 2013-2023 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.cloud.openfeign.protocol;
+
+import feign.Client;
+import org.junit.jupiter.api.Test;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.SpringBootTest.WebEnvironment;
+import org.springframework.cloud.openfeign.loadbalancer.FeignBlockingLoadBalancerClient;
+import org.springframework.test.annotation.DirtiesContext;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author changjin wei(魏昌进)
+ */
+@SpringBootTest(classes = Application.ProtocolController.class, webEnvironment = WebEnvironment.RANDOM_PORT,
+		value = { "spring.application.name=feignclienttest", "spring.cloud.openfeign.circuitbreaker.enabled=false",
+				"spring.cloud.openfeign.httpclient.hc5.enabled=false", "spring.cloud.openfeign.okhttp.enabled=true",
+				"spring.cloud.httpclientfactories.ok.enabled=true", "spring.cloud.loadbalancer.retry.enabled=false",
+				"server.http2.enabled=true", "spring.cloud.openfeign.httpclient.okhttp.protocols=H2_PRIOR_KNOWLEDGE" })
+@DirtiesContext
+class FeignOkProtocolsTests {
+
+	@Autowired
+	private Client feignClient;
+
+	@Autowired
+	private Application.ProtocolClient protocolClient;
+
+	@Test
+	void testFeignClientType() {
+		assertThat(feignClient).isInstanceOf(FeignBlockingLoadBalancerClient.class);
+		FeignBlockingLoadBalancerClient client = (FeignBlockingLoadBalancerClient) feignClient;
+		Client delegate = client.getDelegate();
+		assertThat(delegate).isInstanceOf(feign.okhttp.OkHttpClient.class);
+	}
+
+	@Test
+	void shouldHttp2() {
+		String protocol = protocolClient.getProtocol();
+		assertThat(protocol).isEqualTo("HTTP/2.0");
+	}
+
+}