Fegin是声明式、模块化的Http客户端,可以帮助我们快捷优雅的调用HTTP接口。
在SpringCloud中可以很方便的创建一个Feign客户端,只需声明一个接口,并加上对应的注解就能完成对HTTP接口的调用。
本文不集成注册中心也就不使用Fegin的负载均衡,所以可以理解为一个更简便,高可复用的Http客户端。
SpringBoot版本:2.1.1.RELEASE
必要POM引入
<parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.1.RELEASE</version> </parent> <dependencyManagement> <dependencies> <!--spring-cloud --> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-dependencies</artifactId> <version>${spring-cloud.version}</version> <type>pom</type> <scope>import</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> </dependencies>
Fegin客户端定义
1、@FeignClient 定义接口为Http客户端,调用指定方法,并注入Spring上下文中 参数url:所请求http服务的url、参数config:指定fegin的配置类 2、@PostMapping 为@RequestMapping的组合注解,默认为Post请求调用,注解不多介绍 表名所需要调用的http接口的具体路径,可在url中拼接参数,也可以指定入参的ContentType 3、http接口的返回值格式如果和返回对象属性一致,会反序列化为对应对象。
package com.external.feign; import java.util.List; import java.util.Map; import org.springframework.cloud.openfeign.FeignClient; import org.springframework.web.bind.annotation.PostMapping; import com.external.config.FormFeignConfig; import com.external.dto.response.BaseBispDto; import com.external.dto.response.NiftyRes; import com.external.dto.response.ReportAnalyzesRes; import com.external.dto.response.ReportSummaryRes; import com.external.feign.rpc.BISPResponse; @FeignClient(name="fegin-name", url="${http-url}" , configuration = FormFeignConfig.class) public interface BispClient { /** * @Description * @author zengzp */ @PostMapping(value="/intf?method=XXXX", consumes = {"application/x-www-form-urlencoded"}) public XXXXResponse<BaseBispDto> saveSampleInfo(Map<String, ?> params); /** * @Description * @author zengzp */ @PostMapping(value="/intf?method=XXXX", consumes = {"application/x-www-form-urlencoded"}) public XXXXResponse<NiftyRes> getNiftyDetectionResultReplenish(Map<String, ?> params);
Fegin配置代码
配置日志输出策略与指定对应ContentType的消息的编码与解码
package com.external.config; import org.springframework.beans.factory.ObjectFactory; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.autoconfigure.http.HttpMessageConverters; import org.springframework.cloud.openfeign.support.SpringDecoder; import org.springframework.cloud.openfeign.support.SpringEncoder; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Scope; import feign.Logger; import feign.codec.Decoder; import feign.codec.Encoder; import feign.form.FormEncoder; @Configuration public class FormFeignConfig { @Autowired private ObjectFactory<HttpMessageConverters> messageConverters; @Bean Logger.Level feignLoggerLevel() { return Logger.Level.BASIC; } @Bean @Scope("prototype") Decoder decoder() { return new AllinpayDecoder(new SpringDecoder(messageConverters)); } @Bean @Scope("prototype") Encoder encoder(){ return new FormEncoder(new SpringEncoder(this.messageConverters)); } }
统一响应DTO
package com.external.feign.rpc; import org.springframework.http.HttpStatus; import com.external.common.dto.BaseDto; public class XXXXResponse<T> extends BaseDto { /** * */ private static final long serialVersionUID = 1L; private String code; private String msg; private Long total; private T rows; }