SpringCloud学习笔记（14）----Spring Cloud Netflix之Hystrix对Feign的支持

提示：扫一扫查出行
【扫一扫了解最新限行尾号】
复制提示

1. Hystrix对Feign的支持

添加Feign中IUserBiz的实现类HystrixFallBack：

package com.wangx.cloud.springcloud02consumer.configure;

import com.wangx.cloud.springcloud02consumer.api.UserApi;

import org.springframework.stereotype.Component;

@Component

public class HystrixFallBack implements UserApi {

    @Override

    public String getUser(Integer id) {

        System.out.println("连接超时.....");

        return "system error";

    }

}

使用@component注解注册成组件。在@FeignClient注解里面添加fallback属性即可。

如下：

package com.wangx.cloud.springcloud02consumer.api;

import com.wangx.cloud.springcloud02consumer.configure.FooConfiguration;

import com.wangx.cloud.springcloud02consumer.configure.HystrixFallBack;

import org.springframework.cloud.openfeign.FeignClient;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RequestParam;

@FeignClient(value = "spring-cloud-provider", configuration = FooConfiguration.class, fallback = HystrixFallBack.class)

public interface UserApi {

    @RequestMapping(value = "/user/getUser")

    String getUser(@RequestParam(value = "id") Integer id);

}

当出现请求错误或超时时，就会执行实现类中的方法。

熔断设置

#默认为false，如果想用断路由，要打开这个设置

feign.hystrix.enabled=true

#断路器线程池超时时间,这个值一定要比ribbon超时时间长，毫秒

hystrix.command.default.execution.isolation.thread.timeoutInMilliseconds=16000

单个应用禁用Hystrix

在FooConfiguration中配置一个bean

package com.wangx.cloud.springcloud02consumer.configure;

import feign.Feign;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.context.annotation.Scope;

@Configuration

public class FooConfiguration {

    @Bean

    @Scope("prototype")

    public Feign.Builder feignBuilder() {

        return Feign.builder();

    }

}

配置隔离级别

# 在feign和Ribbon里面配置隔离策略（全局配置）

#hystrix.command.default.execution.isolation.strategy=SEMAPHORE

# 配置单个 ystrixCommandKey在Ribbon下面默认为方法名，在feign下面默认为类名#方法名（参数类型）

#hystrix.command.HystrixCommandKey.execution.isolation.strategy=SEMAPHORE

说明：HystrixCommandKey在Ribbon下面默认为方法名，在feign下面默认为类名#方法名（参数类型）

Feign下的HystrixCommandKey类的配置

package com.wangx.cloud.springcloud02consumer.configure;

import com.netflix.hystrix.HystrixCommand;

import com.netflix.hystrix.HystrixCommand.Setter;

import com.netflix.hystrix.HystrixCommandGroupKey;

import com.netflix.hystrix.HystrixCommandKey;

import feign.Feign;

import feign.Target;

import feign.hystrix.HystrixFeign;

import feign.hystrix.SetterFactory;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.Configuration;

import org.springframework.context.annotation.Scope;

import java.lang.reflect.Method;

@Configuration

public class FooConfiguration {

    @Bean

    @Scope("prototype")

    public Feign.Builder feignBuilder() {

        class RcSetterFactory implements SetterFactory {

            @Override

            public Setter create(Target<?> target, Method method) {

                String groupKey = target.name();

                String commandKey = method.getName();

                return HystrixCommand.Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey(groupKey))

                        .andCommandKey(HystrixCommandKey.Factory.asKey(commandKey));

            }

        }

        return HystrixFeign.builder().setterFactory(new RcSetterFactory());

        //return Feign.builder();

    }

}