SpringCloudAlibaba整合Feign实现远程HTTP调用的简单示例

<!-- openfeign -->
<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>

@EnableFeignClients
public class ContentCenterApplication {
}

import com.coisini.contentcenter.feignclient.TestFeignClient;
import lombok.RequiredArgsConstructor;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequiredArgsConstructor(onConstructor = @__(@Autowired))
public class TestController {

     private final TestFeignClient testFeignClient;

	/**
     * 整合Feign
     * @return
     */
    @GetMapping("test4")
    public String test4() {
        return testFeignClient.test("Coisini");
    }
    
}

import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;

/**
 * @FeignClient(name = "user-center") 
 * name 要请求的微服务的名称
 */
@FeignClient(name = "user-center")
public interface TestFeignClient{

    /**
     * test接口被调用时，feign会构造出 url
     * http://user-center/test/{name} 完成请求
     * @param name
     * @return
     */
    @GetMapping("/test/{name}")
    String test(@PathVariable String name);

}

@RestController
@Slf4j
public class TestController {

    @GetMapping("/test/{name}")
    public String test(@PathVariable String name) {
        log.info("请求...");
        return "hello " + name;
    }

}

feign.client.config: 
  <feignName>:
    connectTimeout: 5000 # 连接超时时间
    readTimeout: 5000 # 读取超时时间
    loggerLevel: full # 日志级别
    errorDecoder: com.example.SimpleErrorDecoder # 错误解码器
    retryer: com.example.SimpleRetryer # 重试策略
    requestInterceptors: com.example.FooRequestInterceptor # 拦截器
    decode404: false # 是否对404错误码解码
    encoder: com.example.SimpleEncoder # 编码器
    decoder: com.example.SimpleDecoder # 解码器
    contract: com.example.SimpleContract # 契约

import feign.Logger;
import org.springframework.context.annotation.Bean;

/**
 * @Description 用户中心 Feign 配置类
 */
public class UserCenterFeignConfiguration {

    @Bean
    public Logger.Level level() {
        return Logger.Level.FULL;
    }

}

@FeignClient(name = "user-center", configuration = UserCenterFeignConfiguration.class)
public interface UserCenterFeignClient {
	...
}

logging:
  level:
    # feign 的日志级别是建立在接口日志级别基础上的
    com.coisini.contentcenter.feignclient.UserCenterFeignClient: debug

logging:
  level:
    com.coisini.contentcenter.feignclient.UserCenterFeignClient: debug

# 自定义配置 feign 日志级别
feign:
  client:
    config:
      # 调用的微服务名称
      user-center:
        loggerLevel: full

import feign.Logger;
import org.springframework.context.annotation.Bean;

/**
 * @Description Feign 全局配置类
 */
public class GlobalFeignConfiguration {

    @Bean
    public Logger.Level level() {
        // feign 日志级别 FULL
        return Logger.Level.FULL;
    }

}

@EnableFeignClients(defaultConfiguration = GlobalFeignConfiguration.class)
@SpringBootApplication
public class ContentCenterApplication {
	...
}

logging:
  level:
    com.coisini.contentcenter.feignclient.UserCenterFeignClient: debug

# 自定义配置 feign 日志级别
feign:
  client:
    config:
      # 全局配置
      default:
        loggerLevel: full