(Thirty-three) java version of spring cloud micro Services Architecture b2b2c integrate e-commerce platform -SpringCloud Hystrix

SpringCloud integration Hystrix

Since the service may call the caller to hang up the service provider, the caller to the service integration Hystrix

The introduction of dependence

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

Start to open the main breaker

@SpringBootApplication
@EnableEurekaClient
//开启断路器
@EnableCircuitBreaker
public class SaleApp {

    @Bean
    @LoadBalanced
    public RestTemplate getRestTemplate() {
        return new RestTemplate();
    }

    public static void main(String[] args) {
        new SpringApplicationBuilder(SaleApp.class).web(true).run(args);
    }
}

Services modified call service

@Service
//对这个类采用全局默认的回退机制，回退方法不能带参数，例如：“getMemberFallback”没有参数
//@DefaultProperties(defaultFallback = "getMemberFallback")
public class MemberService {

    @Autowired
    private RestTemplate restTpl;

    //1、@HystrixCommand、@HystrixProperty这些注解不是SpringCloud注解，而是Hystrix框架提供的
    //2、fallbackMethod当修饰具体方法时，fallbackMethod方法的参数和修饰方法保持一致
    @HystrixCommand(fallbackMethod = "getMemberFallback", groupKey = "MemberGroup", commandKey = "MemberCommandKey", 
            commandProperties = {
            //超时熔断
            @HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds", value = "1000")
    }, threadPoolProperties = {
            @HystrixProperty(name = "coreSize", value = "2")
    })
    public Member getMember(Integer id) {
        try {
            Thread.sleep(500);
        } catch (Exception e) {

        }

        Member member = restTpl.getForObject(
                "http://spring-hy-member/member/{id}", Member.class, id);
        return member;
    }

    public Member getMemberFallback(Integer id) {
        Member m = new Member();
        m.setId(1);
        m.setName("error member");
        return m;
    }
}

Note:
@DefaultProperties: You can configure global fallback mechanism, the fallback method does not take parameters, such as: "getMemberFallback" no parameters
@ HystrixCommand, @ HystrixProperty these annotations are not SpringCloud comment, but Hystrix framework provided
fallbackMethod when modifying specific method, fallbackMethod method of modifying parameters and methods consistent