Source link: https://github.com/google/tiger

DISCLAIMER: This is not an official Google product. Google's production dependency injection frameworks are Dagger and Guice.

Tiger - The fastest java dependency injection framework


Tiger is highly inspired by Dagger, Kudos to those great guys.


If you find a faster DI framework, let me know. I will drop the title as long as it is proved.

Why Tiger?

It is the fastest! Not faster, but the fastest! I have tried it on a big project with ~200 modules. While it takes hundreds of milliseconds to instantiate dagger components, on the same hardware, it only takes a few milliseconds to instantiate Tiger injectors. Minimal amount of code to write therefore easy to maintain, if you need to maintain it at all. You don't need to write components like in Dagger. You don't need to split a module into several modules one for each scope that used by bindings provided by the module. You will feel it is some easy to change the scope of a binding. Just change it. Way to go, isn’t it?

Build up your knowledge

If you are here, you must already be familiar with DI(Dependency Injection) and its advantage. Otherwise wiki will be your friend. DI has been evolving for long time in the different form. But the concept is not really changed much. This document will not repeat these concepts. If you find some concept not explained, google it. Also Guice probably has explained those concept very well.


Tiger is an annotation process. Therefore just build the jar and use it the way that annotation processors are supposed to be used. All environment should work. The sample uses gradle.


Before diving into details, it will be helpful, very helpful, to understand the intended usage of tiger. Tiger is designed to let the machine do as much as possible and let human do as little as possible. It requires minimal information from the developer. From these information, scoped injectors are generated. Application can instances these injectors and use them to inject classes. To achieve this, tiger has distilled the information needed to generate injectors. Here are they, with related annotation.


Usually application has at least one scope, singleton. Even if there is no scoped binding, it is harmless to have a singleton scope. Therefore, tiger requires there always be a scope tree. The root is usually singleton, but not necessary. Details will be shown later in the sample. Tiger generates one injector class for each scope.


It specifies the dependencies between scopes. All the dependency information form a scope tree.


It provides binding information through @Provides annotated methods with optional scope. Now(2016/08/10) we just reuse dagger.Module. In future, dagger.Module will be copied into tiger.Module so that tiger does not need to depend on dagger.

@javax.inject.Inject on ctor

It provides binding information with optional scope.

@tiger.MembersInjector with mandatory scope

It specifies interfaces which includes class that has fields or methods to be injected. Injectors will implement all these interfaces.

@javax.inject.Inject on fields, methods

It specifies the injection points from which injector fans out when injecting an object.


The package for the generated injectors.


It specify the names of the injectors.


This the annotation that triggers the generation processor. @Module, @Inject and @MembersInjector are naturally scattered around the code. For the others, i.e., @ScopeDependency, @PackageForGenerated, @ScopedComponentNames and @GenerationTriggerAnnotation, we suggest to put them into a dedicated java file as the central configuration information for the app.

Here is the depicted code the sample(with some modification)

@GenerationTriggerAnnotation @PackageForGenerated("sample") public class Scopes {

@ScopedComponentNames(scope = Singleton.class, name = "ApplicationInjector" )
  public static class ForApplication {


@ScopedComponentNames(scope = sample.ActivityScoped.class, name = "ActivityInjector" )
  @ScopeDependency(scope = sample.ActivityScoped.class, parent = Singleton.class)
  public static class ForActivityScoped {


Here is how ApplicationInjector is instantiated and used.

ApplicationInjector applicationInjector = new ApplicationInjector.Builder().build();
 PseudoApplication application = new PseudoApplication();

Here is how ActivityInjector is instantiated and used.

ActivityInjector activityInjector = new ActivityInjector.Builder()



The injectors guarantee that scoped bindings will be instantiated at most once within a scope. The application needs to create related injectors for scope objects, e.g., in android, a context scoped injector for each Activity, a singleton scoped injector for the Application.

For Dagger users

As you can see, Tiger reuses annotations from dagger like dagger.Module, dagger.Provides, etc. You can find the javadoc here. We are not going to repeat them here. Of course, Component and Subcomponent is not needed any longer. Producer related stuff is also irrelevant to injection. There is one nice feature from Tiger. You don't need to split modules according to different scopes. Yes, you can put bindings of different scopes into one module. This way you have less modules. And, if you want to change the scope of a binding, just change it, easy.


Inspecting the generate code will help you. If you want more, there is source code. Enjoy injection!


[email protected]


A barcode scanner based on zxing. Support screen auto rotate (both landscape and portrait).

RxJava/RxAndroid way to request permissions on android os marshmallow and above. This library allows the usage of RxJava 2.0.

Updated new version 1.2.0

A sample project to demonstrate how one can catch an unhandled exception in Android and display a custom error dialog.

This compiler will generate you db class, content provider and several helper class for you from a describing file. You can set several options like package name, database name, database version, content authority and others.

An extension to Moshi that provides general purpose, simple and yet useful JsonAdapters that are not present in the main library.

A pure MVC base library on android. Using it, your code can be very clean in MVC pattern: light Activity, light View, light Model.


2D Engines   3D Engines   9-Patch   Action Bars   Activities   ADB   Advertisements   Analytics   Animations   ANR   AOP   API   APK   APT   Architecture   Audio   Autocomplete   Background Processing   Backward Compatibility   Badges   Bar Codes   Benchmarking   Bitmaps   Bluetooth   Blur Effects   Bread Crumbs   BRMS   Browser Extensions   Build Systems   Bundles   Buttons   Caching   Camera   Canvas   Cards   Carousels   Changelog   Checkboxes   Cloud Storages   Color Analysis   Color Pickers   Colors   Comet/Push   Compass Sensors   Conferences   Content Providers   Continuous Integration   Crash Reports   Credit Cards   Credits   CSV   Curl/Flip   Data Binding   Data Generators   Data Structures   Database   Database Browsers   Date &   Debugging   Decompilers   Deep Links   Dependency Injections   Design   Design Patterns   Dex   Dialogs   Distributed Computing   Distribution Platforms   Download Managers   Drawables   Emoji   Emulators   EPUB   Equalizers &   Event Buses   Exception Handling   Face Recognition   Feedback &   File System   File/Directory   Fingerprint   Floating Action   Fonts   Forms   Fragments   FRP   FSM   Functional Programming   Gamepads   Games   Geocaching   Gestures   GIF   Glow Pad   Gradle Plugins   Graphics   Grid Views   Highlighting   HTML   HTTP Mocking   Icons   IDE   IDE Plugins   Image Croppers   Image Loaders   Image Pickers   Image Processing   Image Views   Instrumentation   Intents   Job Schedulers   JSON   Keyboard   Kotlin   Layouts   Library Demos   List View   List Views   Localization   Location   Lock Patterns   Logcat   Logging   Mails   Maps   Markdown   Mathematics   Maven Plugins   MBaaS   Media   Menus   Messaging   MIME   Mobile Web   Native Image   Navigation   NDK   Networking   NFC   NoSQL   Number Pickers   OAuth   Object Mocking   OCR Engines   OpenGL   ORM   Other Pickers   Parallax List   Parcelables   Particle Systems   Password Inputs   PDF   Permissions   Physics Engines   Platforms   Plugin Frameworks   Preferences   Progress Indicators   ProGuard   Properties   Protocol Buffer   Pull To   Purchases   Push/Pull   QR Codes   Quick Return   Radio Buttons   Range Bars   Ratings   Recycler Views   Resources   REST   Ripple Effects   RSS   Screenshots   Scripting   Scroll Views   SDK   Search Inputs   Security   Sensors   Services   Showcase Views   Signatures   Sliding Panels   Snackbars   SOAP   Social Networks   Spannable   Spinners   Splash Screens   SSH   Static Analysis   Status Bars   Styling   SVG   System   Tags   Task Managers   TDD &   Template Engines   Testing   Testing Tools   Text Formatting   Text Views   Text Watchers   Text-to   Toasts   Toolkits For   Tools   Tooltips   Trainings   TV   Twitter   Updaters   USB   User Stories   Utils   Validation   Video   View Adapters   View Pagers   Views   Watch Face   Wearable Data   Wearables   Weather   Web Tools   Web Views   WebRTC   WebSockets   Wheel Widgets   Wi-Fi   Widgets   Windows   Wizards   XML   XMPP   YAML   ZIP Codes