Avian example usage in gradle build

Kotlin+java.nio hello world http server example

Requirements

You will need the following environment to build the project:

• OpenJDK >= 1.7 (jar,javac in PATH)
• Ensure JAVA_HOME is pointing to the OpenJDK
• Build tools (make,gcc,g++ in PATH)
• Git (git in PATH)
• Bash (bash in PATH)

How to build

$ ./gradlew clean standalone

This will download Avian to build/avian directory and then will launch the build of your project into a single self-contained application file less than 4Mb in size.

Drawbacks

• There is a src/util directory containing the primitive thread pool and blocking queue implementations, that should be easily found within the java standard library. The reason for this is that Avian does not implement many parts of jdk and we have to "reinvent a wheel" for some features.
• Performance is worse than with Oracle JDK. I believe this is because Oracle JDK is highly optimized in many ways.

Advanced settings

Avian is a very lightweight JDK implementation. As such, it misses lots of great JDK standard library things. Fortunately there is a way of building your project with the alternative JDK implementations (e.g. OpenJDK).

Build with OpenJDK

You can build the project in more advanced way with the full JDK class library support. To do so, you will need to have the source code and a distribution of OpenJDK. As soon as you get ones, just indicate the path to each of them in the respective properties within gradle.properties file:

OPEN_JDK_PATH=/absolute/path/to/openjdk/distribution
OPEN_JDK_SRC_PATH=/absolute/path/to/openjdk/source/code

Drawbacks

• The proven compatible version of OpenJDK is openjdk-7u111 (as of November 2016). Not sure if others will work as well.
• The resulting size of a self-contained file will be tens of megabytes instead of a few.