2016-06-08 37 views
4

我有一个同时上传多个文件到云存储的方法。它看起来是这样的:RxJava - 上传顺序文件 - 发出下一个项目,当onNext称为

List<String> files = Arrays.asList("file0", "file1", "file2"); 

Observable.from(files) 
     .flatMap(file -> uploadFile(file) 
       .flatMap(done -> notifyFinished(file))) 
     .subscribe(this::onNext, this::onError, this::onCompleted); 


private Observable<Boolean> uploadFile(String file) { 
    Timber.d("Uploading: " + file); 
    return Observable.just(true).delay(6, TimeUnit.SECONDS); 
} 

private Observable<Boolean> notifyFinished(String file) { 
    Timber.d("Notify finished: " + file); 
    return Observable.just(true).delay(3, TimeUnit.SECONDS); 
} 

的这个输出是:

06-09 02:10:04.779 D: Uploading: file0 
06-09 02:10:04.780 D: Uploading: file1 
06-09 02:10:04.781 D: Uploading: file2 
06-09 02:10:10.782 D: Notify finished: file1 
06-09 02:10:10.782 D: Notify finished: file0 
06-09 02:10:10.783 D: Notify finished: file2 
06-09 02:10:13.784 D: onNext 
06-09 02:10:13.786 D: onNext 
06-09 02:10:13.786 D: onNext 
06-09 02:10:13.787 D: onCompleted 

我想让它按顺序工作,比如:

1) Uploading: file0 
2) Notify finished: file0 
3) onNext 
4) Uploading: file1 
5) Notify finished: file1 
6) onNext 
    ... 

是否有可能做这样的事情这与Rx?

编辑

更换第一flatMapconcatMap做的工作。我想,我知道这些运营商之间的差异,但这个例子只是表明,我什么都不知道......现在的输出是:

06-09 02:15:00.581 D: Uploading: file0 
06-09 02:15:06.584 D: Notify finished: file0 
06-09 02:15:09.586 D: onNext 
06-09 02:15:09.587 D: Uploading: file1 
06-09 02:15:15.590 D: Notify finished: file1 
06-09 02:15:18.593 D: onNext 
06-09 02:15:18.595 D: Uploading: file2 
06-09 02:15:24.598 D: Notify finished: file2 
06-09 02:15:27.599 D: onNext 
06-09 02:15:27.601 D: onCompleted 
+0

结合观测什么是你想要做的更多的例子吗?这看起来已经可以顺序工作了。你看到什么顺序? – Whymarrh

+0

示例很糟糕,请检查我的编辑。 – rafakob

回答

5

,如果你想“订购”连续顺序,只需使用concatMap(),而不是flatMap()

1

创建每个文件可观察到的和Concat的三个观测

@Test 
public void testContact() { 

    Observable.concat(Observable.just(uploadFile(file1)), 
         Observable.just(uploadFile(file2)), 
         Observable.just(uploadFile(file3))) 
       .flatMap(file -> notifyFinished(file))) 
       .subscribe(this::onNext, this::onError, this::onCompleted); 
} 

你将不得不作出的方法notifyFinished返回观察到的文件,而不是布尔值。

您也可以使用合并或zip,你在这里https://github.com/politrons/reactive/tree/master/src/test/java/rx/observables/combining

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