A simple Java Looper implementation / example. Only depends on SLF4J for a logging facade.

#> mvn verify

Quickest way is by using JitPack (Also see for instructions on gradle usage)

Add JitPack repository

<repositories> <repository> <id>jitpack.io</id> <url>https://jitpack.io</url> </repository> </repositories> 

Add dependency

<dependency> <groupId>com.github.ivovandongen</groupId> <artifactId>jloop</artifactId> <version>master</version> </dependency> 

A main looper can be created once and can be accessed statically from any other thread for usage after. For a more complete reference see the Unit Test

On the main thread:

 Looper looper = Looper.prepareMainLooper(); looper.run() // Will block indefinitely 

On any other thread:

Looper.prepareMainLooper().post(() -> { // Do what must be done on the main thread  });

Other methods available are Looper#postDelayed and Looper#ask()

For other use cases, a regular looper can be prepared on a Thread. Reference to this looper must be handed to other threads manually:

 Looper looper = Looper.prepare(); looper.run() // Will block indefinitely 

A LooperThread is a convenient way to create a Looper on a new, separate Thread. See the Unit Tests for more details.

LooperThread lp = new LooperThread(); lp.start(); // Will block until backing Looper is ready