public class HelloWorldHystrixCommand extends HystrixCommand<String>{
    private final String name;
    public HelloWorldHystrixCommand(String name) {
        super(HystrixCommandGroupKey.Factory.asKey("ExampleGroup"));
        this.name = name;
    }
 
    @Override
    protected String run() throws Exception {
        //Thread.sleep(100);
        return "hello"+name;
    }
}


public static void main(String[] args){
    String result = new HelloWorldHystrixCommand("test").execute();
    System.out.println(result);
}

public class HelloWorldHystrixObservableCommand extends HystrixObservableCommand<String>{
 
    private final String name;
     
    protected HelloWorldHystrixObservableCommand(String  name) {
        super(HystrixCommandGroupKey.Factory.asKey("ExampleGroup"));
        this.name = name;
    }
     
    @Override
    protected Observable<String> construct() {
        System.out.println("in construct! thread:" + Thread.currentThread().getName());
        　　　　 return (Observable<String>) Observable.create(new Observable.OnSubscribe<String>() {
//            @Override
            public void call(Subscriber<? super String> observer) {
                try {
                    System.out.println("in call of construct! thread:" + Thread.currentThread().getName());
                    if (!observer.isUnsubscribed()) {
//                      observer.onError(getExecutionException());  // 直接抛异常退出，不会往下执行
                        observer.onNext("Hello1" + " thread:" + Thread.currentThread().getName());
                        observer.onNext("Hello2" + " thread:" + Thread.currentThread().getName());
                        observer.onNext(name + " thread:" + Thread.currentThread().getName());
                        System.out.println("complete before------" + " thread:" + Thread.currentThread().getName());
                        observer.onCompleted(); // 不会往下执行observer的任何方法
                        System.out.println("complete after------" + " thread:" + Thread.currentThread().getName());
                        observer.onCompleted(); // 不会执行到
                        observer.onNext("abc"); // 不会执行到
                    }
                } catch (Exception e) {
                    observer.onError(e);
                }
            }
         });
    }
}

public static void main(String[] args) {
　　　　Observable<String> observable = new HelloWorldHystrixObservableCommand("test").observe();
　　　　observable.subscribe(new Subscriber<String>() {
          public void onCompleted() {
    　　    System.out.println("completed");
      }
      public void onError(Throwable throwable) {
            System.out.println("error-----------"+throwable);
      }
      public void onNext(String v) {
        System.out.println("next------------" + v);
          }
　　});
}