RxJava 1 -> RxJava 2 (Disposing Subscriptions)

Migrating from RxJava 1 to RxJava 2? The biggest gotcha isn't what you think—it's how you dispose of subscriptions.

Instacart engineer Kaushik Gopal breaks down the trickiest part of the RxJava 2 migration: managing subscription lifecycles. The Reactive Streams spec changed everything about how you prevent memory leaks in Android apps.

Key Takeaways

• Publisher.subscribe() now returns void, not Subscription like RxJava 1
• Subscriptions renamed to Disposables; use CompositeDisposable instead of CompositeSubscription
• subscribeWith() method lets you treat DisposableSubscriber as both Subscriber and Disposable
• Use .clear() not .dispose() on CompositeDisposable to allow reuse
• Lambda subscriptions still return Disposable; only Subscriber objects need workarounds

The article reveals a critical difference between .clear() and .dispose() that could break your entire subscription management strategy.