Question

我有一个Observable，如果不满足某个条件（即某个网站的响应不成功）我想终止，这样我就可以重新查询网站，并再次调用observable。我该怎么做呢？

这就是我想要做的事情：

Observable.create(new Observable.OnSubscribe<String>() {
    @Override
    public void call(Subscriber<? super String> subscriber) {

        //Perform network actions here

        if (!response.isSuccessful()) {
            //terminate this Observable so I can retrieve the token and call this observable again
        }
    }

});

Answer 1

您可以使用Rx的retry运算符。并且无需终止Observable。

定义了一个自定义异常：

public class FailedException extends RuntimeException{
    // ...
}


private static final int RETRY_COUNT = 3; // max retry counts
Observable.create(new Observable.OnSubscribe<String>() {
        @Override
        public void call(Subscriber<? super String> subscriber) {
            //Perform network actions here
            if (!response.isSuccessful()) {
                // if response is unsucceed, invoke onError method and it will be stop emit data and into retry method.
                subscriber.onError(new FailedException());
            }
        }

    })
    .retry((integer, throwable) -> {
        // Retry network actions when failed.
        // if return true, Observable will be retry to network actions emit data;
        // if return false, you can process in onError() method of Subscribe.
        return throwable instanceof FailedException && integer < RETRY_COUNT;
    })

Answer 2

您可以在订阅前过滤结果。创建observable时不要处理它。

检查observable.filter函数

如何终止Observable？

2 个答案: