Fix FeignClientBuilder fallback (#197)

* fix FeignClientBuilder fallback

* Fix FeignClientBuilder fallback

* Fix FeignClientBuilder fallback

* Update FeignClientBuilderTests.java

* Update FeignClientBuilderTests.java

* Update FeignClientBuilderTests.java

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

@@ -16,6 +16,8 @@
 
 package org.springframework.cloud.openfeign;
 
+import feign.hystrix.FallbackFactory;
+
 import org.springframework.context.ApplicationContext;
 
 /**
@@ -57,8 +59,7 @@ public class FeignClientBuilder {
 			this.feignClientFactoryBean.setContextId(FeignClientsRegistrar.getName(name));
 			// preset default values - these values resemble the default values on the
 			// FeignClient annotation
-			this.url("").path("").decode404(false).fallback(void.class)
-					.fallbackFactory(void.class);
+			this.url("").path("").decode404(false);
 		}
 
 		public Builder url(final String url) {
@@ -81,13 +82,13 @@ public class FeignClientBuilder {
 			return this;
 		}
 
-		public Builder fallback(final Class<T> fallback) {
+		public Builder fallback(final Class<? extends T> fallback) {
 			FeignClientsRegistrar.validateFallback(fallback);
 			this.feignClientFactoryBean.setFallback(fallback);
 			return this;
 		}
 
-		public Builder fallbackFactory(final Class<T> fallbackFactory) {
+		public Builder fallbackFactory(final Class<? extends FallbackFactory<? extends T>> fallbackFactory) {
 			FeignClientsRegistrar.validateFallbackFactory(fallbackFactory);
 			this.feignClientFactoryBean.setFallbackFactory(fallbackFactory);
 			return this;

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

@@ -24,6 +24,7 @@ import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 
+import feign.hystrix.FallbackFactory;
 import org.hamcrest.Matchers;
 import org.junit.Before;
 import org.junit.Rule;
@@ -101,11 +102,11 @@ public class FeignClientBuilderTests {
 	public void forType_preinitializedBuilder() {
 		// when:
 		final FeignClientBuilder.Builder builder = this.feignClientBuilder
-				.forType(FeignClientBuilderTests.class, "TestClient");
+				.forType(TestFeignClient.class, "TestClient");
 
 		// then:
 		assertFactoryBeanField(builder, "applicationContext", this.applicationContext);
-		assertFactoryBeanField(builder, "type", FeignClientBuilderTests.class);
+		assertFactoryBeanField(builder, "type", TestFeignClient.class);
 		assertFactoryBeanField(builder, "name", "TestClient");
 		assertFactoryBeanField(builder, "contextId", "TestClient");
 
@@ -126,21 +127,22 @@ public class FeignClientBuilderTests {
 	public void forType_allFieldsSetOnBuilder() {
 		// when:
 		final FeignClientBuilder.Builder builder = this.feignClientBuilder
-				.forType(FeignClientBuilderTests.class, "TestClient").decode404(true)
-				.fallback(Object.class).fallbackFactory(Object.class).path("Path/")
+				.forType(TestFeignClient.class, "TestClient").decode404(true)
+				.fallback(TestFeignClientFallback.class)
+				.fallbackFactory(TestFeignClientFallbackFactory.class).path("Path/")
 				.url("Url/");
 
 		// then:
 		assertFactoryBeanField(builder, "applicationContext", this.applicationContext);
-		assertFactoryBeanField(builder, "type", FeignClientBuilderTests.class);
+		assertFactoryBeanField(builder, "type", TestFeignClient.class);
 		assertFactoryBeanField(builder, "name", "TestClient");
 
 		// and:
 		assertFactoryBeanField(builder, "url", "http://Url/");
 		assertFactoryBeanField(builder, "path", "/Path");
 		assertFactoryBeanField(builder, "decode404", true);
-		assertFactoryBeanField(builder, "fallback", Object.class);
-		assertFactoryBeanField(builder, "fallbackFactory", Object.class);
+		assertFactoryBeanField(builder, "fallback", TestFeignClientFallback.class);
+		assertFactoryBeanField(builder, "fallbackFactory", TestFeignClientFallbackFactory.class);
 	}
 
 	@Test
@@ -159,4 +161,16 @@ public class FeignClientBuilderTests {
 		builder.build();
 	}
 
+	private interface TestFeignClient {
+	}
+
+	private class TestFeignClientFallback implements TestFeignClient {
+	}
+
+	private class TestFeignClientFallbackFactory implements FallbackFactory<TestFeignClient> {
+		@Override
+		public TestFeignClientFallback create(Throwable throwable) {
+			return new TestFeignClientFallback();
+		}
+	}
 }