RxJava:对多个可观察对象使用相同的Observer调用.subscribe()

Question

同一个观察者在几个可观察对象上调用.subscribe()的行为是什么?

它们会隐式合并吗?还是最后一个人赢了?

例如:

event1.subscribe(myObserver);
event2.subscribe(myObserver);

Answer 1

根据javadoc，只要不取消每个observable返回的Subscription s，该观察者将被订阅给所有的observable 。

我希望如果你多次订阅同一个观察者到一个可观察对象，你会得到多次通知——否则之前的订阅会"神奇地"死亡，这可能会引起麻烦。

// data members
Observable x, y;
void foo(Subscriber a) {
  // is subscriber a already registered with x?
  // Nevermind, I'm gonna make sure it is!
  Subscription s=x.subscribe(a);
  // provoke a change to be caught by 'a'
  // do some work based on whatever Subscriber 'a' captured.
  s.unsubscribe();
}
void bar() {
  Subscriber m;
  Subscription mx=x.subscribe(m);
  Subscription my=y.subscribe(m);
  // do something and then...
  foo(mx); // one would expect the mx subscription is still valid here!!!
  // do some more work
  my.unsubscribe();
  mx.unsubscribe();
}