spring-cloud-hystrix使用

世界上并没有完美的程序，但是我们并不因此而沮丧，因为写程序就是一个不断追求完美的过程。

Java API的形式：

public class CustomCommand extends HystrixCommand<Object> {

    protected CustomCommand () {
        super(
                Setter.withGroupKey(HystrixCommandGroupKey.Factory.asKey("group1"))
                        .andCommandKey(HystrixCommandKey.Factory.asKey("CustomController"))
                        .andThreadPoolKey(HystrixThreadPoolKey.Factory.asKey("customThreadPool"))
                        .andCommandPropertiesDefaults(HystrixCommandProperties.Setter()
                                .withCircuitBreakerSleepWindowInMilliseconds(5000))
                        .andThreadPoolPropertiesDefaults(HystrixThreadPoolProperties.Setter()
                                .withCoreSize(1)
                                .withMaxQueueSize(200))
        );
    }

    @Override
    protected Object run() throws Exception {
        throw new RuntimeException();
        //return "controller调用";
    }

    @Override
    protected Object getFallback() {
        return "降级了";
    }
}

使用：

@RestController
public class CustomController {
    @GetMapping("/hystrix")
    public Object hystrix () {
        return new CustomCommand().execute();
    }
}

注解形式：
首先要在启动类中加@EnableHystrix注解

@SpringBootApplication
@EnableEurekaClient
@EnableHystrix
public class Client1Application {
    public static void main(String[] args) {
        SpringApplication.run(Client1Application.class, args);
    }
}

使用：

@GetMapping("/hystrix2")
@HystrixCommand(fallbackMethod = "exceptionFallBack",
threadPoolKey = "customThreadPool2",
threadPoolProperties = {
        @HystrixProperty(name="coreSize", value="1"),
},
commandProperties = {
        @HystrixProperty(name="execution.isolation.thread.timeoutInMilliseconds", value="100")
})
public Object hystrix2 () throws InterruptedException {
    System.out.println("当前线程：" + Thread.currentThread().getName());
    //return "hystrix2Controller";
    throw new RuntimeException();
}

public Object exceptionFallBack () {
    return "降级了2";
}