The feign of Springcloud learning

I. About Feigin

Feigin is a templated, declarative HTTP client that feign can simplify HTTP request access by binding annotations to an interface. Of course, we can also customize the custom decoder (XML or JSON format parsing) and error handling when creating feign objects.

Two. Add Springcloud support for feign

Gradle configuration:

Compile (' org.springframework.cloud:spring-cloud-starter-feign ')

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Feigin the most basic methods of use:

1 InterfaceGitHub {2@RequestLine ("Get/repos/{owner}/{repo}/contributors")3List<contributor> Contributors (@Param ("owner") String owner, @Param ("Repo") String repo);4 }5 6 Static classContributor {7 String login;8   intcontributions;9 }Ten  One  Public Static voidMain (String ... args) { AGitHub GitHub =Feign.builder () -. Decoder (NewGsondecoder ()) -. Target (GitHub.class, "https://api.github.com"); the  -   //Fetch and print a list of the contributors to this library. -List<contributor> contributors = Github.contributors ("Openfeign", "feign"); -    for(contributor contributor:contributors) { +System.out.println (Contributor.login + "(" + contributor.contributions + ")"); -   } +}

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Feign sends an HTTP request in JSON and XML format:

1 Interfaceloginclient {2 3@RequestLine ("POST/")4@Headers ("Content-type:application/xml")5@Body ("<login \" user_name\ "=\" {user_name}\ "\" password\ "=\" {password}\ "/>")6   voidXML (@Param ("user_name") String user, @Param ("Password") String password);7 8@RequestLine ("POST/")9@Headers ("Content-type:application/json")Ten   //JSON curly braces must be escaped! One@Body ("%7b\" user_name\ ": \" {user_name}\ ", \" password\ ": \" {password}\ "%7d") A   voidJSON (@Param ("user_name") String user, @Param ("Password") String password); -}

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Note the example needs to add support for Gson

Feign send the code for HTTPS to trust all certificates:

1 Finaltrustmanager[] Trustallcerts =Newtrustmanager[]{NewX509trustmanager () {2 @Override3              Public voidcheckclienttrusted (4 java.security.cert.x509certificate[] chain,5 String authtype) {6             }7 8 @Override9              Public voidcheckservertrusted (Ten java.security.cert.x509certificate[] chain, One String authtype) { A             } -  - @Override the              Publicjava.security.cert.x509certificate[] Getacceptedissuers () { -                 return NULL; -             } -         }}; +         FinalSslcontext Sslcontext = sslcontext.getinstance ("TLSv1"); -Sslcontext.init (NULL, Trustallcerts, +                 Newjava.security.SecureRandom ()); A         //Create an SSL socket factory with our All-trusting manager at         FinalSslsocketfactory sslsocketfactory =Sslcontext - . Getsocketfactory (); -Feign.builder (). Client (NewClient.default (Sslsocketfactory, (S, sslsession)true));

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Three. Using feign in Springcloud

For example, the registration center has the following services:

1) Configuration of application.yml:

Spring:  application:    name:demo-Consumereureka:  client:    service-URL:      Defaultzone:http://Localhost:8080/eureka,http://localhost: 8081/ EurekaServer:  8090

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2) Create an interface

1  PackageCom.bdqn.lyrk.consumer.demo.api;2 3 Importorg.springframework.cloud.netflix.feign.FeignClient;4 Importorg.springframework.web.bind.annotation.RequestMapping;5 6@FeignClient ("Demo")7  Public InterfaceDemoconfigservice {8 9@RequestMapping ("/demo.do")Ten String Demoservice (); One}

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Note the annotations on the interface: the parameters in the @FeignClient ("demo") annotations are the service names registered in the Eureka

3) Write the Startup class:

 PackageCom.bdqn.lyrk.consumer.demo;ImportCom.bdqn.lyrk.consumer.demo.api.DemoConfigService;Importorg.springframework.boot.SpringApplication;Importorg.springframework.boot.autoconfigure.SpringBootApplication;Importorg.springframework.cloud.client.discovery.EnableDiscoveryClient;Importorg.springframework.cloud.netflix.feign.EnableFeignClients;Importorg.springframework.context.configurableapplicationcontext;@ Enablediscoveryclient@enablefeignclients@springbootapplication Public classDemoconsumerprovider { Public Static voidMain (string[] args) {Configurableapplicationcontext ApplicationContext= Springapplication.run (Democonsumerprovider.class, args); Democonfigservice Democonfigservice= Applicationcontext.getbean (Democonfigservice.class);    System.out.println (Democonfigservice.demoservice ()); }}

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Note Add @enablefeignclients on the startup class to turn on the feign feature

Post-run output:

At this point we can see a lot of code about our access to the service using the feign client

The feign of Springcloud learning