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Project Directory
Maven Dependency
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" 3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 4 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 5 <modelVersion>4.0.0</modelVersion> 6 7 <groupId>org.fool.feign</groupId> 8 <artifactId>hello-feign</artifactId> 9 <version>1.0-SNAPSHOT</version> 10 11 <parent> 12 <groupId>org.springframework.boot</groupId> 13 <artifactId>spring-boot-starter-parent</artifactId> 14 <version>2.2.0.RELEASE</version> 15 </parent> 16 17 <dependencies> 18 <dependency> 19 <groupId>org.springframework.boot</groupId> 20 <artifactId>spring-boot-starter-web</artifactId> 21 <exclusions> 22 <exclusion> 23 <groupId>org.springframework.boot</groupId> 24 <artifactId>spring-boot-starter-tomcat</artifactId> 25 </exclusion> 26 </exclusions> 27 </dependency> 28 29 <dependency> 30 <groupId>org.springframework.boot</groupId> 31 <artifactId>spring-boot-starter-jetty</artifactId> 32 <exclusions> 33 <exclusion> 34 <groupId>org.eclipse.jetty.websocket</groupId> 35 <artifactId>websocket-server</artifactId> 36 </exclusion> 37 <exclusion> 38 <groupId>org.eclipse.jetty.websocket</groupId> 39 <artifactId>javax-websocket-server-impl</artifactId> 40 </exclusion> 41 </exclusions> 42 </dependency> 43 44 <dependency> 45 <groupId>org.projectlombok</groupId> 46 <artifactId>lombok</artifactId> 47 </dependency> 48 49 <dependency> 50 <groupId>org.springframework.cloud</groupId> 51 <artifactId>spring-cloud-starter-openfeign</artifactId> 52 <version>2.1.3.RELEASE</version> 53 </dependency> 54 55 <dependency> 56 <groupId>com.google.code.gson</groupId> 57 <artifactId>gson</artifactId> 58 </dependency> 59 60 <dependency> 61 <groupId>org.springframework.boot</groupId> 62 <artifactId>spring-boot-starter-test</artifactId> 63 <scope>test</scope> 64 </dependency> 65 </dependencies> 66 67 <build> 68 <plugins> 69 <plugin> 70 <groupId>org.springframework.boot</groupId> 71 <artifactId>spring-boot-maven-plugin</artifactId> 72 </plugin> 73 </plugins> 74 </build> 75 </project>
application.properties
1 server.port=8188 2 3 feign.hystrix.enabled=true 4 hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds=10000 5 hystrix.threadpool.default.coreSize=10
Source Code
Application.java
1 package org.fool.feign; 2 3 import org.springframework.boot.SpringApplication; 4 import org.springframework.boot.autoconfigure.SpringBootApplication; 5 import org.springframework.cloud.openfeign.EnableFeignClients; 6 7 @SpringBootApplication 8 @EnableFeignClients 9 public class Application { 10 public static void main(String[] args) { 11 SpringApplication.run(Application.class, args); 12 } 13 }
Note: 使用Feign需要加上 @EnableFeignClients 注解
AbstractFallbackFactory.java
1 package org.fool.feign.client; 2 3 import feign.hystrix.FallbackFactory; 4 import org.fool.feign.common.LogDomain; 5 import org.fool.feign.common.ResultCode; 6 import org.fool.feign.contract.response.ApplicationResponse; 7 import org.fool.feign.logger.ApplicationLogger; 8 import org.fool.feign.logger.ApplicationLoggerFactory; 9 import org.fool.feign.util.JsonUtils; 10 11 public abstract class AbstractFallbackFactory<T> implements FallbackFactory<T> { 12 protected final ApplicationLogger LOGGER = ApplicationLoggerFactory.getLogger(getClass()); 13 private static final String DEFAULT_MESSAGE = "isolation by hystrix"; 14 15 String handleExceptions(Throwable cause, String message) { 16 LOGGER.error(LogDomain.CLIENT, message, cause); 17 18 ApplicationResponse response = ApplicationResponse.builder() 19 .resultCode(ResultCode.INTERNAL_ERROR) 20 .message(ResultCode.INTERNAL_ERROR + ":" + DEFAULT_MESSAGE) 21 .build(); 22 23 return JsonUtils.objectToJson(response); 24 } 25 }
OrderClient.java
1 package org.fool.feign.client; 2 3 import org.fool.feign.config.FeignConfiguration; 4 import org.fool.feign.contract.request.DemoRequest; 5 import org.springframework.cloud.openfeign.FeignClient; 6 import org.springframework.stereotype.Component; 7 import org.springframework.web.bind.annotation.PostMapping; 8 import org.springframework.web.bind.annotation.RequestBody; 9 10 import java.net.URI; 11 12 @FeignClient(name = "ORDER-SERVICE", url = "url-placeholder", 13 fallbackFactory = OrderClient.OrderClientFallbackFactory.class, configuration = FeignConfiguration.class) 14 public interface OrderClient { 15 16 @PostMapping(value = "/demo") 17 String queryOrder(URI uri, @RequestBody DemoRequest orderRequest); 18 19 @Component 20 class OrderClientFallbackFactory extends AbstractFallbackFactory<OrderClient> { 21 @Override 22 public OrderClient create(Throwable throwable) { 23 return new OrderClient() { 24 @Override 25 public String queryOrder(URI uri, DemoRequest orderRequest) { 26 String message = "failed to query_order with " + orderRequest + " url: " + uri.toString(); 27 return handleExceptions(throwable, message); 28 } 29 }; 30 } 31 } 32 }
Note:
通常第一个红框输入的是远程服务的URL，第二个红框则没有URI uri 参数，这里为了实现远程调用模版接口相同，请求URL不同，采用如下图所示实现
ApplicationTest.java
1 package org.fool.feign.test; 2 3 import org.fool.feign.Application; 4 import org.fool.feign.client.OrderClient; 5 import org.fool.feign.contract.request.DemoRequest; 6 import org.junit.Test; 7 import org.junit.runner.RunWith; 8 import org.springframework.beans.factory.annotation.Autowired; 9 import org.springframework.boot.test.context.SpringBootTest; 10 import org.springframework.test.context.junit4.SpringRunner; 11 12 import java.net.URI; 13 14 @RunWith(SpringRunner.class) 15 @SpringBootTest(classes = Application.class) 16 public class ApplicationTest { 17 18 @Autowired 19 private OrderClient orderClient; 20 21 @Test 22 public void test() throws Exception { 23 String url = "http://localhost:8188/order/v1/resource"; 24 25 DemoRequest request = new DemoRequest(); 26 request.setOrderTime("2019-11-11"); 27 request.setBizTag("order"); 28 29 String result = orderClient.queryOrder(new URI(url), request); 30 System.out.println(result); 31 } 32 }
Note: 实现动态调用如下图红框所示，动态传如一个URL
Console Output
