Feign + Hystrix 服务熔断和服务降级
三丰 soft张三丰
本机IP为 192.168.1.102
1.新建 Maven 项目 feign 2.. 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>com.java</groupId>
<artifactId>feign</artifactId>
<version>1.0.0-SNAPSHOT</version>
<name>${project.artifactId}</name>
<!-- 配置版本常量 -->
<properties>
<jdk.version>1.8</jdk.version>
<spring.cloud.version>2.0.0.RELEASE</spring.cloud.version>
</properties>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.0.5.RELEASE</version>
</parent>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
<version>${spring.cloud.version}</version>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
<version>${spring.cloud.version}</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>fastjson</artifactId>
<version>1.2.49</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<scope>provided</scope>
</dependency>
<!-- 热部署 -->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>springloaded</artifactId>
<version>1.2.8.RELEASE</version>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
</dependency>
</dependencies>
<build>
<finalName>${project.artifactId}</finalName>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>${jdk.version}</source>
<target>${jdk.version}</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<executions>
<execution>
<goals>
<goal>repackage</goal>
</goals>
</execution>
</executions>
</plugin>
</plugins>
</build>
</project>
3.. application.yml
server:
port: 80
feign:
hystrix:
enabled: true
eureka:
client:
register-with-eureka: false
service-url:
defaultZone: http://192.168.1.102:8080/eureka/
#defaultZone: http://s0.com:8080/eureka/,http://s1.com:8080/eureka/,http://s2.com:8080/eureka/
4.. HostService.java
package com.java.feign.service;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import com.alibaba.fastjson.JSONObject;
@FeignClient(value = "MICROSERVICE", fallbackFactory = HostServiceFallbackFactory.class)
public interface HostService {
@GetMapping("/getHostMessage/{id}")
public JSONObject getHostMessage(@PathVariable(value = "id") String id);
}
5.HostServiceFallbackFactory.java
package com.java.feign.service;
import org.springframework.stereotype.Component;
import com.alibaba.fastjson.JSONObject;
import feign.hystrix.FallbackFactory;
@Component
public class HostServiceFallbackFactory implements FallbackFactory<HostService> {
@Override
public HostService create(Throwable cause) {
return new HostService() {
@Override
public JSONObject getHostMessage(String id) {
JSONObject json = new JSONObject();
json.put("id", id);
json.put("description", "服务异常演习专用！");
json.put("msg", cause.getMessage());
return json;
}
};
}
}
6.. HostController.java
package com.java.feign.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import com.alibaba.fastjson.JSONObject;
import com.java.feign.service.HostService;
@RestController
public class HostController {
@Autowired
private HostService hostService;
@GetMapping("/getHostMessage/{id}")
public JSONObject getHostMessage(@PathVariable String id) {
return hostService.getHostMessage(id);
}
}
7.. FeignStarter.java
package com.java.feign;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.boot.web.servlet.support.SpringBootServletInitializer;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
import org.springframework.context.annotation.ComponentScan;
@EnableEurekaClient
@SpringBootApplication
@EnableFeignClients(basePackages = { "com.java.feign.service" })
@ComponentScan(basePackages = { "com.java.feign" })
public class FeignStarter extends SpringBootServletInitializer {
public static void main(String[] args) {
SpringApplication.run(FeignStarter.class, args);
}
@Override
protected SpringApplicationBuilder configure(SpringApplicationBuilder builder) {
return builder.sources(FeignStarter.class);
}
}
- 运行测试
启动 Eureka 服务注册中心，参考 https://www.cnblogs.com/jonban/p/eureka.html
启动 MicroService 微服务， 参考 https://www.cnblogs.com/jonban/p/microservice.html
启动 Feign服务，运行 FeignStarter.java
浏览器输入URL
http://192.168.1.102/getHostMessage/hello
或
http://127.0.0.1/getHostMessage/hello
返回数据如下：
{"hostname":"F6RK2EXYAFARPPS","hostAddress":"192.168.1.102","id":"hello"}
截图如下：
搭建成功，程序正常运行。
下面开始测试异常
关掉微服务提供者 microservice 服务器
浏览器输入URL
http://192.168.1.102/getHostMessage/hello
或
http://127.0.0.1/getHostMessage/hello
返回数据如下：
{"msg":"com.netflix.client.ClientException: Load balancer does not have available server for client: MICROSERVICE","description":"服务异常演习专用！","id":"hello"}
截图如下：
服务异常生效，符合预期结果。
