创建项目

以之前的msa-weather-report-eureka-feign-gateway为蓝本，创建msa-weather-report-eureka-feign-gateway-hystrix项目

修改build.gradle配置，添加Hystrix依赖：

//依赖关系dependencies {
       //该依赖用于编译阶段	compile('org.springframework.boot:spring-boot-starter-web')    //添加Spring Boot Thymeleaf Starter的依赖    compile('org.springframework.boot:spring-boot-starter-thymeleaf')    //Eureka Client    compile('org.springframework.cloud:spring-cloud-starter-netflix-eureka-client')    //Feign    compile('org.springframework.cloud:spring-cloud-starter-openfeign:2.0.0.M3')    //Hystrix    compile('org.springframework.cloud:spring-cloud-starter-netflix-hystrix')    //该依赖用于测试阶段    testCompile('org.springframework.boot:spring-boot-starter-test')}

修改com.study.spring.cloud.weather包下的Application类，加入@EnableCircuitBreaker注解：

package com.study.spring.cloud.weather;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;import org.springframework.cloud.client.discovery.EnableDiscoveryClient;import org.springframework.cloud.netflix.feign.EnableFeignClients;/* * @SpringBootApplication注解声明Spring Boot应用 * 作用等同于@Configuration, @EnableAutoConfiguration, @ComponentScan， * 简化Spring配置*/@SpringBootApplication//启用可发现的客户端@EnableDiscoveryClient//启用Feign@EnableFeignClients//启用Hystrix@EnableCircuitBreaker//Application类一定要处于整个工程的根目录下，这样它才能根据配置去扫描子节点下的Spring的Beanpublic class Application {
   	public static void main(String[] args) {
   		SpringApplication.run(Application.class, args);	}}

在com.study.spring.cloud.weather.service包下新建类DataClientFallback：

package com.study.spring.cloud.weather.service;import com.study.spring.cloud.weather.vo.City;import com.study.spring.cloud.weather.vo.WeatherResponse;import org.springframework.stereotype.Component;import java.util.ArrayList;import java.util.List;//声明为Bean@Componentpublic class DataClientFallback implements DataClient {
   	@Override	public List
   
     listCity() throws Exception {
   		List
    
      cityList=null;		cityList=new ArrayList<>();		City city=new City();		city.setCityId("101020100");		city.setCityName("上海");		cityList.add(city);		city=new City();		city.setCityId("101010100");		city.setCityName("北京");		cityList.add(city);		return cityList;	}	@Override	public WeatherResponse getDataByCityId(String cityId) {
   		return null;	}}

修改com.study.spring.cloud.weather.service包下的WeatherReportServiceImpl类：

package com.study.spring.cloud.weather.service;import com.study.spring.cloud.weather.vo.Weather;import com.study.spring.cloud.weather.vo.WeatherResponse;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;@Servicepublic class WeatherReportServiceImpl implements WeatherReportService {
   	@Autowired	private DataClient dataClient;	@Override	public Weather getDataByCityId(String cityId) {
   		//由天气数据API微服务来提供数据		WeatherResponse resp=dataClient.getDataByCityId(cityId);		Weather data=null;		if(resp!=null){
   			data=resp.getData();		}		return data;	}}

修改com.study.spring.cloud.weather.service包下的DataClient接口：

package com.study.spring.cloud.weather.service;import com.study.spring.cloud.weather.vo.City;import com.study.spring.cloud.weather.vo.WeatherResponse;import org.springframework.cloud.netflix.feign.FeignClient;import org.springframework.web.bind.annotation.GetMapping;import org.springframework.web.bind.annotation.PathVariable;import java.util.List;@FeignClient(name = "msa-weather-eureka-client-zuul",fallback = DataClientFallback.class)public interface DataClient {
   	//获取城市列表	@GetMapping("/city/cities")	List
   
     listCity() throws Exception;	//根据城市id查询天气数据	@GetMapping("/data/weather/cityId/{cityId}")	WeatherResponse getDataByCityId(@PathVariable("cityId") String cityId);}

修改前端页面report.html：

    
       
       
       
       天气预报    
           
                
     天气
            
             
    
        
                
                     
      城市名称
            
     
            
                     
                          空气质量指数：                
            
     
            
                     
                          当前温度：                
            
     
            
                     
                          温馨提示：                
            
     
            
                     
                          
                               
        日期
                        
        天气类型
                        
        最高温度
                        
        最低温度
                        
        风向
                    
       
                
      
            
     
        
    
        
                
                     
                          天气数据API微服务暂不可用！

修改application.properties配置文件：

#热部署静态文件spring.thymeleaf.cache=false#应用名称spring.application.name=msa-weather-report-eureka-feign-gateway-hystrix#注册服务器的URLeureka.client.service-url.defaultZone=http://localhost:8761/eureka/#请求服务时的超时时间feign.client.config.feignName.connect-timeout=5000#读数据时的超时时间feign.client.config.feignName.read-timeout=5000#在feign客户端中启用断路器功能feign.hystrix.enabled=true