Add CircuitBreakerNameResolver (#575)

docs/src/main/asciidoc/spring-cloud-openfeign.adoc

@@ -348,7 +348,22 @@ public class FooConfiguration {
 }
 ----
 
-The circuit breaker name follows this pattern `<feignClientName>#<calledMethod>`. When calling a `@FeignClient` with name `foo` and the called interface method is `bar` then the circuit breaker name will be `foo_bar`.
+The circuit breaker name follows this pattern `<feignClientClassName>#<calledMethod>(<parameterTypes>)`. When calling a `@FeignClient` with `FooClient` interface and the called interface method that has no parameters is `bar` then the circuit breaker name will be `FooClient#bar()`.
+
+NOTE: As of 2020.0.2, the circuit breaker name pattern has changed from `<feignClientName>_<calledMethod>`.
+Using `CircuitBreakerNameResolver` introduced in 2020.0.4, circuit breaker names can retain the old pattern.
+
+Providing a bean of `CircuitBreakerNameResolver`, you can change the circuit breaker name pattern.
+[source,java,indent=0]
+----
+@Configuration
+public class FooConfiguration {
+	@Bean
+	public CircuitBreakerNameResolver circuitBreakerNameResolver() {
+		return (String feignClientName, Target<?> target, Method method) -> feignClientName + "_" + method.getName();
+	}
+}
+----
 
 To enable Spring Cloud CircuitBreaker group set the `feign.circuitbreaker.group.enabled` property to `true` (by default `false`).
 

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

@@ -0,0 +1,34 @@
+/*
+ * Copyright 2013-2021 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;
+
+import java.lang.reflect.Method;
+
+import feign.Target;
+
+/**
+ * Used to resolve a circuitbreaker name which will be used in
+ * {@link org.springframework.cloud.client.circuitbreaker.CircuitBreakerFactory}.
+ *
+ * @author Kwangyong Kim
+ * @since 2020.0.4
+ */
+public interface CircuitBreakerNameResolver {
+
+	String resolveCircuitBreakerName(String feignClientName, Target<?> target, Method method);
+
+}

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

@@ -17,6 +17,7 @@
 package org.springframework.cloud.openfeign;
 
 import java.io.IOException;
+import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Timer;
@@ -29,6 +30,7 @@ import com.fasterxml.jackson.databind.Module;
 import feign.Client;
 import feign.Feign;
 import feign.RequestInterceptor;
+import feign.Target;
 import feign.hc5.ApacheHttp5Client;
 import feign.httpclient.ApacheHttpClient;
 import feign.okhttp.OkHttpClient;
@@ -79,6 +81,7 @@ import org.springframework.security.oauth2.client.resource.OAuth2ProtectedResour
  * @author Olga Maciaszek-Sharma
  * @author Nguyen Ky Thanh
  * @author Andrii Bohutskyi
+ * @author Kwangyong Kim
  */
 @Configuration(proxyBeanMethods = false)
 @ConditionalOnClass(Feign.class)
@@ -146,12 +149,29 @@ public class FeignAutoConfiguration {
 			return new DefaultTargeter();
 		}
 
+		@Bean
+		@ConditionalOnMissingBean(CircuitBreakerNameResolver.class)
+		public CircuitBreakerNameResolver circuitBreakerNameResolver() {
+			return new DefaultCircuitBreakerNameResolver();
+		}
+
 		@Bean
 		@ConditionalOnMissingBean
 		@ConditionalOnBean(CircuitBreakerFactory.class)
 		public Targeter circuitBreakerFeignTargeter(CircuitBreakerFactory circuitBreakerFactory,
-				@Value("${feign.circuitbreaker.group.enabled:false}") boolean circuitBreakerGroupEnabled) {
-			return new FeignCircuitBreakerTargeter(circuitBreakerFactory, circuitBreakerGroupEnabled);
+				@Value("${feign.circuitbreaker.group.enabled:false}") boolean circuitBreakerGroupEnabled,
+				CircuitBreakerNameResolver circuitBreakerNameResolver) {
+			return new FeignCircuitBreakerTargeter(circuitBreakerFactory, circuitBreakerGroupEnabled,
+					circuitBreakerNameResolver);
+		}
+
+		static class DefaultCircuitBreakerNameResolver implements CircuitBreakerNameResolver {
+
+			@Override
+			public String resolveCircuitBreakerName(String feignClientName, Target<?> target, Method method) {
+				return Feign.configKey(target.getClass(), method);
+			}
+
 		}
 
 	}

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

@@ -27,6 +27,7 @@ import org.springframework.cloud.client.circuitbreaker.CircuitBreakerFactory;
  *
  * @author Marcin Grzejszczak
  * @author Andrii Bohutskyi
+ * @author Kwangyong Kim
  * @since 3.0.0
  */
 public final class FeignCircuitBreaker {
@@ -53,6 +54,8 @@ public final class FeignCircuitBreaker {
 
 		private boolean circuitBreakerGroupEnabled;
 
+		private CircuitBreakerNameResolver circuitBreakerNameResolver;
+
 		Builder circuitBreakerFactory(CircuitBreakerFactory circuitBreakerFactory) {
 			this.circuitBreakerFactory = circuitBreakerFactory;
 			return this;
@@ -68,6 +71,11 @@ public final class FeignCircuitBreaker {
 			return this;
 		}
 
+		Builder circuitBreakerNameResolver(CircuitBreakerNameResolver circuitBreakerNameResolver) {
+			this.circuitBreakerNameResolver = circuitBreakerNameResolver;
+			return this;
+		}
+
 		public <T> T target(Target<T> target, T fallback) {
 			return build(fallback != null ? new FallbackFactory.Default<T>(fallback) : null).newInstance(target);
 		}
@@ -82,9 +90,9 @@ public final class FeignCircuitBreaker {
 		}
 
 		public Feign build(final FallbackFactory<?> nullableFallbackFactory) {
-			super.invocationHandlerFactory(
-					(target, dispatch) -> new FeignCircuitBreakerInvocationHandler(circuitBreakerFactory,
-							feignClientName, target, dispatch, nullableFallbackFactory, circuitBreakerGroupEnabled));
+			super.invocationHandlerFactory((target, dispatch) -> new FeignCircuitBreakerInvocationHandler(
+					circuitBreakerFactory, feignClientName, target, dispatch, nullableFallbackFactory,
+					circuitBreakerGroupEnabled, circuitBreakerNameResolver));
 			return super.build();
 		}
 

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

@@ -24,7 +24,6 @@ import java.util.Map;
 import java.util.function.Function;
 import java.util.function.Supplier;
 
-import feign.Feign;
 import feign.InvocationHandlerFactory;
 import feign.Target;
 
@@ -51,9 +50,11 @@ class FeignCircuitBreakerInvocationHandler implements InvocationHandler {
 
 	private final boolean circuitBreakerGroupEnabled;
 
+	private final CircuitBreakerNameResolver circuitBreakerNameResolver;
+
 	FeignCircuitBreakerInvocationHandler(CircuitBreakerFactory factory, String feignClientName, Target<?> target,
 			Map<Method, InvocationHandlerFactory.MethodHandler> dispatch, FallbackFactory<?> nullableFallbackFactory,
-			boolean circuitBreakerGroupEnabled) {
+			boolean circuitBreakerGroupEnabled, CircuitBreakerNameResolver circuitBreakerNameResolver) {
 		this.factory = factory;
 		this.feignClientName = feignClientName;
 		this.target = checkNotNull(target, "target");
@@ -61,6 +62,7 @@ class FeignCircuitBreakerInvocationHandler implements InvocationHandler {
 		this.fallbackMethodMap = toFallbackMethod(dispatch);
 		this.nullableFallbackFactory = nullableFallbackFactory;
 		this.circuitBreakerGroupEnabled = circuitBreakerGroupEnabled;
+		this.circuitBreakerNameResolver = circuitBreakerNameResolver;
 	}
 
 	@Override
@@ -82,7 +84,8 @@ class FeignCircuitBreakerInvocationHandler implements InvocationHandler {
 		else if ("toString".equals(method.getName())) {
 			return toString();
 		}
-		String circuitName = Feign.configKey(target.type(), method);
+
+		String circuitName = circuitBreakerNameResolver.resolveCircuitBreakerName(feignClientName, target, method);
 		CircuitBreaker circuitBreaker = circuitBreakerGroupEnabled ? factory.create(circuitName, feignClientName)
 				: factory.create(circuitName);
 		Supplier<Object> supplier = asSupplier(method, args);

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

@@ -29,9 +29,13 @@ class FeignCircuitBreakerTargeter implements Targeter {
 
 	private final boolean circuitBreakerGroupEnabled;
 
-	FeignCircuitBreakerTargeter(CircuitBreakerFactory circuitBreakerFactory, boolean circuitBreakerGroupEnabled) {
+	private final CircuitBreakerNameResolver circuitBreakerNameResolver;
+
+	FeignCircuitBreakerTargeter(CircuitBreakerFactory circuitBreakerFactory, boolean circuitBreakerGroupEnabled,
+			CircuitBreakerNameResolver circuitBreakerNameResolver) {
 		this.circuitBreakerFactory = circuitBreakerFactory;
 		this.circuitBreakerGroupEnabled = circuitBreakerGroupEnabled;
+		this.circuitBreakerNameResolver = circuitBreakerNameResolver;
 	}
 
 	@Override
@@ -85,7 +89,8 @@ class FeignCircuitBreakerTargeter implements Targeter {
 
 	private FeignCircuitBreaker.Builder builder(String feignClientName, FeignCircuitBreaker.Builder builder) {
 		return builder.circuitBreakerFactory(circuitBreakerFactory).feignClientName(feignClientName)
-				.circuitBreakerGroupEnabled(circuitBreakerGroupEnabled);
+				.circuitBreakerGroupEnabled(circuitBreakerGroupEnabled)
+				.circuitBreakerNameResolver(circuitBreakerNameResolver);
 	}
 
 }

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

@@ -16,12 +16,16 @@
 
 package org.springframework.cloud.openfeign;
 
+import java.lang.reflect.Method;
+
+import feign.Target;
 import org.assertj.core.api.Condition;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.cloud.client.circuitbreaker.CircuitBreakerFactory;
+import org.springframework.cloud.openfeign.FeignAutoConfiguration.CircuitBreakerPresentFeignTargeterConfiguration.DefaultCircuitBreakerNameResolver;
 import org.springframework.context.ConfigurableApplicationContext;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -31,6 +35,7 @@ import static org.mockito.Mockito.mock;
  * @author Tim Peeters
  * @author Olga Maciaszek-Sharma
  * @author Andrii Bohutskyi
+ * @author Kwangyong Kim
  */
 class FeignAutoConfigurationTests {
 
@@ -50,6 +55,8 @@ class FeignAutoConfigurationTests {
 				.withPropertyValues("feign.circuitbreaker.enabled=true").run(ctx -> {
 					assertOnlyOneTargeterPresent(ctx, FeignCircuitBreakerTargeter.class);
 					assertThatFeignCircuitBreakerTargeterHasGroupEnabledPropertyWithValue(ctx, false);
+					assertThatFeignCircuitBreakerTargeterHasSameCircuitBreakerNameResolver(ctx,
+							DefaultCircuitBreakerNameResolver.class);
 				});
 	}
 
@@ -63,6 +70,17 @@ class FeignAutoConfigurationTests {
 				});
 	}
 
+	@Test
+	void shouldInstantiateFeignCircuitBreakerTargeterWhenEnabledWithCustomCircuitBreakerNameResolver() {
+		runner.withBean(CircuitBreakerFactory.class, () -> mock(CircuitBreakerFactory.class))
+				.withBean(CircuitBreakerNameResolver.class, CustomCircuitBreakerNameResolver::new)
+				.withPropertyValues("feign.circuitbreaker.enabled=true").run(ctx -> {
+					assertOnlyOneTargeterPresent(ctx, FeignCircuitBreakerTargeter.class);
+					assertThatFeignCircuitBreakerTargeterHasSameCircuitBreakerNameResolver(ctx,
+							CustomCircuitBreakerNameResolver.class);
+				});
+	}
+
 	private void assertOnlyOneTargeterPresent(ConfigurableApplicationContext ctx, Class<?> beanClass) {
 		assertThat(ctx.getBeansOfType(Targeter.class)).hasSize(1).hasValueSatisfying(new Condition<>(
 				beanClass::isInstance, String.format("Targeter should be an instance of %s", beanClass)));
@@ -75,4 +93,19 @@ class FeignAutoConfigurationTests {
 		assertThat(bean).hasFieldOrPropertyWithValue("circuitBreakerGroupEnabled", expectedValue);
 	}
 
+	private void assertThatFeignCircuitBreakerTargeterHasSameCircuitBreakerNameResolver(
+			ConfigurableApplicationContext ctx, Class<?> beanClass) {
+		final CircuitBreakerNameResolver bean = ctx.getBean(CircuitBreakerNameResolver.class);
+		assertThat(bean).isExactlyInstanceOf(beanClass);
+	}
+
+	static class CustomCircuitBreakerNameResolver implements CircuitBreakerNameResolver {
+
+		@Override
+		public String resolveCircuitBreakerName(String feignClientName, Target<?> target, Method method) {
+			return feignClientName + "_" + method.getName();
+		}
+
+	}
+
 }