Spring Cloud (DALSTON.SR5)--zuul Gateway-hystrix fallback

When we configure the gateway to invoke the service of the cluster, the Ribbon route filter is executed, which is encapsulated as a hystrix command to execute when forwarding, and the Hystrix command has fault tolerance if there is a problem with the "source service" (such as a timeout), the The Hystrix command will trigger a fallback, and we need to implement the Org.springframework.cloud.netflix.zuul.filters.route.ZuulFallbackProvider interface, which mainly needs to implement Getroute method, Fallbackresponse method, the Getroute method mainly returns the name of the route used to match the route of the Hystrix fallback method; The Fallbackresponse method mainly returns the return information of the fallback, the sample code is as follows:

• Fallback Method Class

  The Getroute method is implemented, and the return Helloworld-provider represents the fallback class for the Helloworld-provider service, implements the Fallbackresponse method, and indicates the specific content returned by the fallback method

  Package Org.lixue.zuul;

  ??

  Import Org.springframework.cloud.netflix.zuul.filters.route.ZuulFallbackProvider;

  Import org.springframework.http.HttpHeaders;

  Import Org.springframework.http.HttpStatus;

  Import Org.springframework.http.MediaType;

  Import Org.springframework.http.client.ClientHttpResponse;

  ??

  Import Java.io.ByteArrayInputStream;

  Import java.io.IOException;

  Import Java.io.InputStream;

  ??

  Public class Helloworldfallback implements zuulfallbackprovider{

  @Override

  Public String Getroute () {

  return"Helloworld-provider" ;

  }

  ??

  @Override

  Public clienthttpresponse Fallbackresponse () {

  return new Clienthttpresponse () {

  @Override

  Public httpstatus Getstatuscode ()throwsioexception{

  return Httpstatus. OK;

  }

  ??

  @Override

  public int Getrawstatuscode ()throwsioexception{

  return Httpstatus. OK. Value ();

  }

  ??

  @Override

  Public String getstatustext ()throwsioexception{

  return H Ttpstatus. OK. toString ();

  }

  ??

  @Override

  Public void Close () {

  ??

  }

  ??

  @Override

  Public InputStream getbody () throws ioexception{

  return new Bytearrayinputstream ("fallback". GetBytes ());

  }

  ??

  @Override

  Public httpheaders getheaders () {

  Httpheaders headers=new httpheaders ();

  Headers.setcontenttype (mediatype. Text_plain );

  return headers;

  }

  };

  }

  }

  ??

• Zuul Configuration Class

  Create a configuration class and create an instance Bean of the fallback class in the configuration class

  Package Org.lixue.zuul;

  ??

  Import org.springframework.context.annotation. Bean;

  Import org.springframework.context.annotation. Configuration;

  ??

  @Configuration

  Public class zuulfallbackconfiguration{

  ??

  @Bean

  Public helloworldfallback Helloworldfallback () {

  return new Helloworldfallback ();

  }

  }

  ??

• Increase Routing configuration

  #配置应用名称

  Spring

  Application:

  Name: spring-cloud-zuul-microservices

  #服务端口

  Server

  Port: 9200

  #设置eureka服务注册中心的地址 if multiple comma-separated

  Eureka

  Client

  Service-url:

  #defaultZone表示默认的区域的eureka服务地址, multiple partitions using commas

  Defaultzone: http://eurekaserver01:9000/eureka/

  ??

  #zuul路由配置

  Zuul:

  Routes

  Hello

  Path: /hello/**

  serviceId: Helloworld-provider

  ??

• Test validation

  the project relies on a eureka-sserver, Service-provider service that starts Eureka-server and Service-provider services first, and then starts Spring-cloud-zuul-microservices Service, Access to http://localhost:9200/hello/speaks?names=123 address, you can see the normal return, as follows:

  {"123": "Hello World 123 port=8080"}

  At this point, the Service-provider service is turned off again, and you can see that the Service-provider service is inaccessible and the data for the fallback method is returned, as follows:

  Fallback

Spring Cloud (DALSTON.SR5)--zuul Gateway-hystrix fallback