Spring Cloud之统一fallback接口

川长思鸟来 2022-01-28 13:27 299阅读 0赞

# [Spring Cloud之统一fallback接口][Spring Cloud_fallback] #

每个方法都配备一个fallback方法

![1179709-20181115233050403-962230362.png][]

不利于开发的

用类的方式

并且整个方法都是在同一个线程池里面的

主要对于client的修改：

![1179709-20181116151444878-113776630.png][]

pom:

<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>com.toov5</groupId>
    		<artifactId>parent</artifactId>
    		<version>0.0.1-SNAPSHOT</version>
    	</parent>
    	<artifactId>toov5-api-order-service-impl</artifactId>
    
    	<dependencies>
    		<dependency>
               <groupId>com.toov5</groupId>
    			<artifactId>toov5-api-order-service</artifactId>
    			<version>0.0.1-SNAPSHOT</version>
    		</dependency>
    		
         <dependency>
               <groupId>com.toov5</groupId>
    			<artifactId>toov5-api-member-service</artifactId>
    			<version>0.0.1-SNAPSHOT</version>
    		</dependency>
    		
    		
    	</dependencies>
    
    
    </project>

实现类

package com.toov5.api.service.impl;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
    import com.toov5.api.entity.UserEntity;
    import com.toov5.api.feign.MemberServiceFeign;
    import com.toov5.api.service.IOrderService;
    import com.toov5.base.BaseApiService;
    import com.toov5.base.ResponseBase;
    
    @RestController
    public class OrderServiceImpl extends BaseApiService implements IOrderService {
        @Autowired
        private MemberServiceFeign memberServiceFeign;
    
        @RequestMapping("/orderToMmeber")
        public String orderToMember(String name) {
            UserEntity user = memberServiceFeign.getMember(name);
            return user == null ? "没有" : user.toString();
        }
    
        @RequestMapping("/orderToMemberUserInfo")
        public ResponseBase orderToMemberUserInfo() {
            return memberServiceFeign.getUserInfo();
        }
    
        @HystrixCommand(fallbackMethod = "orderToMemberUserInfoHystrixFallback")
        @RequestMapping("/orderToMemberUserInfoHystrix")
        public ResponseBase orderToMemberUserInfoHystrix() {
            System.out.println("orderToMemberUserInfoHystrix" + "线程池名称" + Thread.currentThread().getName());
            return memberServiceFeign.getUserInfo();
        }
    
        public ResponseBase orderToMemberUserInfoHystrixFallback() {
            return setResultSuccess("请稍后再试~");
        }
    
        @RequestMapping("/orderToMemberUserInfoHystrixdSecond")
        public ResponseBase orderToMemberUserInfoHystrix_demo02() {
            System.out.println("orderToMemberUserInfoHystrix" + "线程池名称" + Thread.currentThread().getName());
            return memberServiceFeign.getUserInfo();
        }
    
        @RequestMapping("/orderInfo")
        public ResponseBase orderInfo() {
            System.out.println("orderInfo" + "线程池名称" + Thread.currentThread().getName());
            return setResultSuccess();
        }
    
    }

feign

package com.toov5.api.feign;
    
    import org.springframework.cloud.openfeign.FeignClient;
    
    import com.toov5.api.fallback.MemberServiceFallback;
    import com.toov5.api.service.IMemberService;
    @FeignClient(value="app-toov5-member",fallback = MemberServiceFallback.class)
    public interface MemberServiceFeign extends IMemberService {
      
    }

fallback类

package com.toov5.api.fallback;
    
    import org.springframework.stereotype.Component;
    import org.springframework.web.bind.annotation.RequestMapping;
    
    import com.toov5.api.entity.UserEntity;
    import com.toov5.api.feign.MemberServiceFeign;
    import com.toov5.base.BaseApiService;
    import com.toov5.base.ResponseBase;
    
    @Component
    @RequestMapping("fallback/")   //这个可以防止 容器中有与父类重复的 requestMapping！！！
    public class MemberServiceFallback extends BaseApiService implements  MemberServiceFeign {
        
         @Override
        public ResponseBase getUserInfo() {
             return setResultError("来自类的提示:系统错误,请稍后重试!");
        }
         
        @Override
        public UserEntity getMember(String name) {
            // TODO Auto-generated method stub
            return null;
        }
    
    }

启动类：

package com.toov5.api;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.cloud.netflix.hystrix.EnableHystrix;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    @SpringBootApplication(scanBasePackages={"com.toov5.*"})
    @EnableEurekaClient
    @EnableFeignClients
    @EnableHystrix
    public class AppOrder {
       public static void main(String[] args) {
        SpringApplication.run(AppOrder.class, args);
    }
    }

yml

###服务启动端口号
    server:
      port: 8020
    ###服务名称(服务注册到eureka名称)  
    spring:
        application:
            name: app-toov5-order
    ###服务注册到eureka地址
    eureka:
      client:
        service-url:
               defaultZone: http://localhost:8100/eureka
    
               
    ###因为该应用为注册中心，不会注册自己
        register-with-eureka: true
    ###是否需要从eureka上获取注册信息
        fetch-registry: true
    
        ###设置feign客户端超时时间
    ribbon:
    ###指的是建立连接所用的时间，适用于网络状况正常的情况下，两端连接所用的时间。
     ReadTimeout: 5000
    ###指的是建立连接后从服务器读取到可用资源所用的时间。 
     ConnectTimeout: 5000
      
      #spring cloud 默认开启ribbon 
      
    ##开启Hystrix断路器  
    feign:
      hystrix:
        enabled: true
    
    #### hystrix禁止服务超时时间
    #hystrix:  
    # command: 
    #   default: 
    #      execution:   
    #       timeout: 
    #        enabled: false

启动后：

![1179709-20181116151956909-497201342.png][]

感谢：https://www.jb51.net/article/138758.htm 这篇文章的参考！

对于报错：

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'requestMappingHandlerMapping' defined in class path resource \[org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfiguration$EnableWebMvcConfiguration.class\]: Invocation of init method failed; nested exception is java.lang.IllegalStateException: Ambiguous mapping. Cannot map 'com.toov5.api.feign.MemberServiceFeign' method  
public abstract com.toov5.base.ResponseBase com.toov5.api.service.IMemberService.getUserInfo()  
to \{\[/getUserInfo\]\}: There is already 'memberServiceFallback' bean metho

的解决办法在 fallback的类上面加上

@RequestMapping("fallback/")   //这个可以防止 容器中有与父类重复的 requestMapping！！！

[Spring Cloud_fallback]: https://www.cnblogs.com/toov5/p/9966908.html
[1179709-20181115233050403-962230362.png]: /images/20220128/0e922c55eacc4cb0ade9fca5f18ed89b.png
[1179709-20181116151444878-113776630.png]: /images/20220128/1baaa07458f34cc8a6c23cef8a97b096.png
[1179709-20181116151956909-497201342.png]: /images/20220128/d5015f2eda4c4bf2877ce4fbe8df55d3.png