Feign是一个很好用的REST通讯包，十分强大。
1、MyFeignClient
package com.neohope.springcloud.test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;
import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
import feign.hystrix.FallbackFactory;
import org.springframework.stereotype.Component;
@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients(clients = {MyFeignClient.IServiceClient.class})
@RestController
public class MyFeignClient
{
@Value("${spring.application.name}")
private String appName;
@RequestMapping("/appName")
public String appName() {
return appName;
}
public static void main(String[] args)
{
new SpringApplicationBuilder(MyFeignClient.class).web(true).run(args);
}
@RequestMapping("/")
public String hello() {
return "It works";
}
@Autowired
private IServiceClient aClient;
@RequestMapping("/invokeC")
public String invokeC() {
return aClient.invokeA();
}
@RequestMapping("/invokeC/{clientName}")
String invokeC(@PathVariable("clientName") String clientName)
{
if(aClient==null)
{
return "aClient is null";
}
else
{
//return aClient.invokeA(clientName);
return aClient.invokeA();
}
}
//primary = false
@FeignClient(name="netflix-feign-server", configuration = MyFeignClientConfiguration.class, fallbackFactory=HystrixClientFallbackFactory.class)
public interface IServiceClient {
@RequestMapping(method = RequestMethod.GET, value = "/invokeA")
String invokeA();
//@RequestMapping(method = RequestMethod.GET, value = "/invokeA/{clientName}", consumes = "application/json")
//String invokeA(@PathVariable("clientName") String clientName);
}
@Component
public static class HystrixClientFallbackFactory implements FallbackFactory<IServiceClient>{
@Override
public IServiceClient create(final Throwable cause) {
return new IServiceClient() {
@Override
public String invokeA()
{
return "invokeA failed: "+cause.getMessage();
}
//@Override
//public String invokeA(String clientName)
//{
// return "invokeA with clientName "+clientName+" failed: "+cause.getMessage();
//}
};
}
}
}
2、MyFeignClientConfiguration
package com.neohope.springcloud.test;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import feign.Logger;
import feign.auth.BasicAuthRequestInterceptor;
@Configuration
public class MyFeignClientConfiguration {
@Bean
public BasicAuthRequestInterceptor basicAuthRequestInterceptor() {
return new BasicAuthRequestInterceptor("user", "hystrix");
}
/*
@Bean
Logger.Level feignLoggerLevel() {
return Logger.Level.FULL;
}
*/
}
3、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>
<parent>
<groupId>org.springframework.cloud.stream.app</groupId>
<artifactId>app-starters-build</artifactId>
<version>1.1.3.M1</version>
</parent>
<groupId>com.neohope.springcloud.test</groupId>
<artifactId>netflix-feign-client</artifactId>
<version>1.0.0</version>
<packaging>jar</packaging>
<name>netflix-feign-client</name>
<url>http://maven.apache.org</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>4.3.6.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>4.3.6.RELEASE</version>
</dependency>
<dependency>
<groupId>com.netflix.hystrix</groupId>
<artifactId>hystrix-javanica</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-feign</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-hystrix</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
<version>1.3.0.M1</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot</artifactId>
<version>1.5.1.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-autoconfigure</artifactId>
<version>1.5.1.RELEASE</version>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<scope>test</scope>
</dependency>
</dependencies>
<repositories>
<repository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/libs-milestone</url>
<snapshots>
<enabled>false</enabled>
</snapshots>
</repository>
</repositories>
</project>
4、application.properties
spring.application.name=feign-client
server.port=7002
security.user.name=user
security.user.password=hystrix
eureka.client.serviceUrl.defaultZone=http://user:hystrix@localhost:7000/eureka/
eureka.client.preferSameZoneEureka=true
eureka.client.healthcheck.enabled=true
eureka.instance.metadataMap.zone = zone1
eureka.instance.statusPageUrlPath=${management.context-path}/info
eureka.instance.healthCheckUrlPath=${management.context-path}/health
eureka.instance.lease-renewal-interval-in-seconds=5
eureka.instance.lease-expiration-duration-in-seconds=10
feign.hystrix.enabled=true
#feign.compression.request.enabled=true
#feign.compression.response.enabled=true
#feign.compression.request.enabled=true
#feign.compression.request.mime-types=text/xml,application/xml,application/json
#feign.compression.request.min-request-size=2048
#NONE,BASIC,HEADERS,FULL
logging.level.com.neohope.springcloud.test.MyFeignClient.IServiceClient=BASIC