Add native image support.

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

@@ -44,6 +44,10 @@ import okhttp3.ConnectionPool;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
+import org.springframework.aot.hint.MemberCategory;
+import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.aot.hint.RuntimeHintsRegistrar;
+import org.springframework.aot.hint.TypeReference;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
@@ -73,6 +77,7 @@ import org.springframework.security.oauth2.client.AuthorizedClientServiceOAuth2A
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
 import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
+import org.springframework.util.ClassUtils;
 
 /**
  * @author Spencer Gibb
@@ -373,3 +378,17 @@ public class FeignAutoConfiguration {
 	}
 
 }
+
+class FeignHints implements RuntimeHintsRegistrar {
+
+	@Override
+	public void registerHints(RuntimeHints hints, ClassLoader classLoader) {
+		if (!ClassUtils.isPresent("feign.Feign", classLoader)) {
+			return;
+		}
+		hints.reflection().registerType(TypeReference.of(FeignClientFactoryBean.class),
+				hint -> hint.withMembers(MemberCategory.INVOKE_DECLARED_CONSTRUCTORS,
+						MemberCategory.INVOKE_DECLARED_METHODS, MemberCategory.DECLARED_FIELDS));
+	}
+
+}

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

@@ -71,7 +71,7 @@ import org.springframework.util.StringUtils;
 class FeignClientsRegistrar implements ImportBeanDefinitionRegistrar, ResourceLoaderAware, EnvironmentAware {
 
 	// patterned after Spring Integration IntegrationComponentScanRegistrar
-	// and RibbonClientsConfigurationRegistgrar
+	// and RibbonClientsConfigurationRegistrar
 
 	private ResourceLoader resourceLoader;
 

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

@@ -25,6 +25,7 @@ import javax.lang.model.element.Modifier;
 
 import org.springframework.aot.generate.GenerationContext;
 import org.springframework.aot.generate.MethodReference;
+import org.springframework.aot.hint.ProxyHints;
 import org.springframework.beans.MutablePropertyValues;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.FactoryBean;
@@ -100,16 +101,20 @@ public class FeignClientBeanFactoryInitializationAotProcessor
 		@Override
 		public void applyTo(GenerationContext generationContext,
 				BeanFactoryInitializationCode beanFactoryInitializationCode) {
+			ProxyHints proxyHints = generationContext.getRuntimeHints().proxies();
 			Set<String> feignClientRegistrationMethods = feignClientBeanDefinitions.values().stream()
 					.map(beanDefinition -> {
 						Assert.notNull(beanDefinition, "beanDefinition cannot be null");
 						Assert.isInstanceOf(GenericBeanDefinition.class, beanDefinition);
 						GenericBeanDefinition registeredBeanDefinition = (GenericBeanDefinition) beanDefinition;
 						MutablePropertyValues feignClientProperties = registeredBeanDefinition.getPropertyValues();
+						String className = (String) feignClientProperties.get("type");
+						Assert.notNull(className, "className cannot be null");
+						Class clazz = ClassUtils.resolveClassName(className, null);
+						proxyHints.registerJdkProxy(clazz);
 						return beanFactoryInitializationCode.getMethods()
-								.add(buildMethodName((String) feignClientProperties.get("type")),
-										method -> generateFeignClientRegistrationMethod(method, feignClientProperties,
-												registeredBeanDefinition))
+								.add(buildMethodName(className), method -> generateFeignClientRegistrationMethod(method,
+										feignClientProperties, registeredBeanDefinition))
 								.getName();
 					}).collect(Collectors.toSet());
 			MethodReference initializerMethod = beanFactoryInitializationCode.getMethods()

spring-cloud-openfeign-core/src/main/resources/META-INF/spring/aot.factories

@@ -0,0 +1,2 @@
+org.springframework.aot.hint.RuntimeHintsRegistrar=\
+org.springframework.cloud.openfeign.FeignHints

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

@@ -160,7 +160,6 @@ public class FeignAotTests {
 
 	}
 
-	// TODO: verify other annotation parameters
 	@FeignClient(value = "test-with-config", configuration = TestConfiguration.class)
 	interface TestFeignClientWithConfig {