初始化

.gitignore

+/.classpath
+/.project
+/*.log
+/.settings
+/target

pom.xml

+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>me.rainsay</groupId>
+  <artifactId>first-demo</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <packaging>jar</packaging>
+
+  <name>testdemo</name>
+  <url>http://maven.apache.org</url>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+  </properties>
+
+  <parent>
+      <groupId>org.springframework.boot</groupId>
+      <artifactId>spring-boot-starter-parent</artifactId>
+      <version>2.0.5.RELEASE</version>
+  </parent>
+	<dependencyManagement>
+	    <dependencies>
+	        <dependency>
+	            <groupId>org.springframework.cloud</groupId>
+	            <artifactId>spring-cloud-dependencies</artifactId>
+	            <version>Finchley.RELEASE</version>
+	            <type>pom</type>
+	            <scope>import</scope>
+	        </dependency>
+	    </dependencies>
+	</dependencyManagement>
+  <dependencies>
+  	<dependency>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-starter-web</artifactId>
+    </dependency>
+    <dependency>
+        <groupId>org.springframework.cloud</groupId>
+        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
+    </dependency>
+    <dependency>
+	   	<groupId>org.springframework.cloud</groupId>
+	   	<artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
+	</dependency>
+	<dependency>
+        <groupId>org.springframework.cloud</groupId>
+        <artifactId>spring-cloud-starter-openfeign</artifactId>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+		<groupId>org.springframework.boot</groupId>
+		<artifactId>spring-boot-starter-test</artifactId>
+		<scope>test</scope>
+	</dependency>
+    <dependency>
+    	<groupId>com.github.tomakehurst</groupId>
+	    <artifactId>wiremock</artifactId>
+	    <version>2.19.0</version>
+	    <scope>test</scope>
+	</dependency>
+  </dependencies> 
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>org.springframework.boot</groupId>
+        <artifactId>spring-boot-maven-plugin</artifactId>
+     </plugin>
+	</plugins>
+ </build>
+</project>

src/main/java/me/rainsay/testdemo/App.java

+package me.rainsay.testdemo;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
+import org.springframework.cloud.openfeign.EnableFeignClients;
+
+/**
+ * Hello world!
+ *
+ */
+@SpringBootApplication
+@EnableCircuitBreaker
+@EnableFeignClients
+public class App 
+{
+
+    public static void main( String[] args )
+    {
+        SpringApplication.run(App.class, args);
+    }
+}

src/main/java/me/rainsay/testdemo/controller/HelloController.java

+package me.rainsay.testdemo.controller;
+
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class HelloController {
+	
+	private final static Logger log = LoggerFactory.getLogger(HelloController.class);
+
+	@GetMapping("/hello")
+	public String hello() {
+		log.info("GET /hello success");
+		return "hello world from spring boot";
+	}
+}

src/main/java/me/rainsay/testdemo/feign/BookClient.java

+package me.rainsay.testdemo.feign;
+
+import org.springframework.cloud.openfeign.FeignClient;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestMethod;
+
+import me.rainsay.testdemo.feign.fallback.BookClientFallback;
+
+@FeignClient(name = "book-server", fallback = BookClientFallback.class)
+public interface BookClient {
+	
+	@RequestMapping(value = "/book", method = RequestMethod.GET)
+	String hello();
+}

src/main/java/me/rainsay/testdemo/feign/fallback/BookClientFallback.java

+package me.rainsay.testdemo.feign.fallback;
+
+import org.springframework.stereotype.Component;
+
+import me.rainsay.testdemo.feign.BookClient;
+
+@Component
+public class BookClientFallback implements BookClient {
+
+	@Override
+	public String hello() {
+		return "No hello";
+	}
+
+}

src/main/resources/application.yml

+eureka:
+  client:
+    enabled: false
+    
+logging:
+  file: test.log
\ No newline at end of file

src/test/java/me/rainsay/testdemo/SomeTest.java

+package me.rainsay.testdemo;
+import static com.github.tomakehurst.wiremock.client.WireMock.*;
+import static com.github.tomakehurst.wiremock.core.WireMockConfiguration.wireMockConfig;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+
+import org.junit.Before;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.context.TestConfiguration;
+import org.springframework.cloud.netflix.ribbon.StaticServerList;
+import org.springframework.context.annotation.Bean;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringRunner;
+
+import com.github.tomakehurst.wiremock.junit.WireMockRule;
+import com.google.common.net.MediaType;
+import com.netflix.loadbalancer.Server;
+import com.netflix.loadbalancer.ServerList;
+
+import me.rainsay.testdemo.feign.BookClient;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest(properties = {
+		"feign.hystrix.enabled=true",
+		"eureka.client.enabled=false"
+})
+@ContextConfiguration(classes = {
+		SomeTest.LocalRibbonClientConfiguration.class
+})
+public class SomeTest {
+	@ClassRule
+	public static WireMockRule wireMock = new WireMockRule(wireMockConfig().dynamicPort());
+	
+	@Autowired
+	BookClient bookClient;
+	
+	@Before
+	public void setup() {
+		stubFor(get(urlEqualTo("/book"))
+				.willReturn(aResponse()
+						.withStatus(200)
+						.withHeader("Content-Type", MediaType.PLAIN_TEXT_UTF_8.toString())
+						.withBody("Hello World"))
+				);
+	}
+	
+	@Test
+	public void testHello() {
+		String hello = bookClient.hello();
+		assertNotNull("shoud not be null",hello);
+		assertEquals("Hello World", hello);
+	}
+	
+	@Test
+	public void testHelloFallback() {
+		stubFor(get(urlEqualTo("/book"))
+                .willReturn(aResponse().withFixedDelay(60000)));
+		String hello = bookClient.hello();
+		assertNotNull(hello);
+		assertEquals("No hello", hello);
+	}
+	
+	@TestConfiguration
+	public static class LocalRibbonClientConfiguration {
+		@Bean
+		public ServerList<Server> ribbonServerList() {
+			return new StaticServerList<>(new Server("localhost", wireMock.port()));
+		}
+	}
+}