rohankumardubey / completable-future-example

CompletableFuture, Future and Streams

This project uses a sample use case to compare Java's CompletableFuture with plain Future and other approaches like plain Java and the Stream API.

There is a story behind this code to make it more fun and, at the same time, to give a goal to the sample code so it's easier to compare. Welcome to the Java Bank Robbery with CompletableFutures, Futures and Streams.

Blog

The comparison between these approaches, and a good introduction to CompletableFuture is available at The Practical Developer Site. I recommend you to read that guide to follow the codebase.

Code

The code is split into three main parts:

• The main application class App, which runs the different code alternatives and shows the result.
• The objects used to represent this story: Actions, Loot and Thief.
• The alternatives used to execute the story:
  • SingleThreadOpenSafeLock contains two approaches, both single-threaded: plain, imperative Java and Stream API based.
  • FutureOpenSafeLock implements the plan using Java Futures, also in imperative-ish way.
  • CompletableFutureOpenSafeLock uses a few important methods of the CompletableFuture API to demonstrate how powerful it is to solve composed, multi-threaded problems.

Remember that the conclusions of the comparison are also included in the guide so, check it out now!