Pure Java Game Of Life
This is an implementation of Conway's Game Of Life, a zero-player game featuring an infinite plane of square cells which evolve their state as alive or dead according to a finite set of rules:
- Any live cell with fewer than two live neighbours dies, as if caused by under-population.
- Any live cell with two or three live neighbours lives on to the next generation.
- Any live cell with more than three live neighbours dies, as if by over-population.
- Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.
The Game Of Life is a common kata to exercise in a code retreat, or to get your feet wet with a different technology. Keep the problem the same and change the conditions around it to cover new ground.
Technologies used
This project tries to take a modern approach to Java software development, producing a self-contained application which embeds everything needed to run on any JVM in a development, CI or production environment.
- Java 8 with lambdas support
- Gradle for build automation and dependency resolution (substitutes both Ant and Maven)
- Jetty as an embedded server to respond to HTTP requests
- Jersey for building the RESTful web service calculating new generations of a plane, using JAX-RS
- Freemarker templating engine to build HTML
- Log4j 2 for logging, encapsulated behind the interface slf4j.
On the testing side of things:
- JUnit 4 for unit testing infrastructure
- Mockito for Test Doubles
- JUnit Quickcheck for property-based testing
- Selenium for browser-based testing
How to run
Clone the project, then run:
./gradlew
The Gradle Wrapper will install itself.
Run
./gradlew test
to run unit, property-based and Selenium tests.
Standalone
Then run
./gradlew installDist
cd build/install/game-of-life
bin/game-of-life
to install an instance in the build/ subfolder. Load [http://localhost:8080/planes/a-block-and-bar] in your browser to see the evolution of a test plane. The patterns featured in the sample are a stable block and a rotating bar, along with a lone cell vanishing after the first generation.
The plane shown is a configurable window of 10x10 cells having the plane origin as the top corner, but the underlying engine is capable of extending the plane dimensions automatically to use all available memory.
Inside a server
./gradlew war
will generate a WAR file at build/libs/game-of-life-*.war. This WAR file can be deployed inside a servlet container.
To check how the WAR file is working, run:
./gradlew jettyRunWar -i
which will spin up a temporary Jetty 6.x (very old) container and deploy the WAR inside it.