What's different in 3.0

Table of contents

• Introduction
  • Maven coordinates
  • Java 8
  • Package structure
• Behavior changes
• API changes
  • New Types
  • API additions
  • API expansions
  • API removals
  • Moved components
• Miscellaneous

Introduction

Maven coordinates

JavaDocs

The documentation of the various components can be found at

• http://reactivex.io/RxJava/3.x/javadoc/

Sub-version specific documentation is available under a version tag, for example

• http://reactivex.io/RxJava/3.x/javadoc/3.0.0-RC9

(replace 3.0.0-RC9 with 3.0.1 and so on in the future).

The documentation of the current snapshot is under

• http://reactivex.io/RxJava/3.x/javadoc/snapshot

Java 8

Package structure

RxJava 3 components are located under the io.reactivex.rxjava3 package (RxJava 1 has rx and RxJava 2 is just io.reactivex. This allows version 3 to live side by side with the earlier versions. In addition, the core types of RxJava (Flowable, Observer, etc.) have been moved to io.reactivex.rxjava3.core.

Component	RxJava 2	RxJava 3
Core	io.reactivex	io.reactivex.rxjava3.core
Annotations	io.reactivex.annotations	io.reactivex.rxjava3.annotations
Disposables	io.reactivex.disposables	io.reactivex.rxjava3.disposables
Exceptions	io.reactivex.exceptions	io.reactivex.rxjava3.exceptions
Functions	io.reactivex.functions	io.reactivex.rxjava3.functions
Flowables	io.reactivex.flowables	io.reactivex.rxjava3.flowables
Observables	io.reactivex.observables	io.reactivex.rxjava3.observables
Subjects	io.reactivex.subjects	io.reactivex.rxjava3.subjects
Processors	io.reactivex.processors	io.reactivex.rxjava3.processors
Observers	io.reactivex.observers	io.reactivex.rxjava3.observers
Subscribers	io.reactivex.subscribers	io.reactivex.rxjava3.subscribers
Parallel	io.reactivex.parallel	io.reactivex.rxjava3.parallel
Internal	io.reactivex.internal	io.reactivex.rxjava3.internal

⚠️ Note on running "Organize Imports" from the IDE

Due to naming matches, IDE's tend to import java.util.Observable instead of picking RxJava's io.reactivex.rxjava3.core.Observable. One can usually have the IDE ignore java.util.Observable and java.util.Observer, or otherwise, specify an explicit import io.reactivex.rxjava3.core.Observable; in the affected files.

Also since RxJava 3 now requires a Java 8 runtime, the standard library functional interfaces, such as java.util.function.Function, may be picked instead of io.reactivex.rxjava3.functions.Function. IDEs tend to give a non-descriptive errors such as "Function can't be converted to Function", omitting the fact about the package differences.

Behavior changes

API changes

New Types

Moved components

API additions

API expansions

API removals

Miscellaneous