ortools-java

Packages Google OR-Tools as a self-extracting jar file at Maven coordinates com.skaggsm.ortools:ortools-natives-all:8.0.8283.

Why?

There are two types of existing solutions: those that require the natives to be bundled manually, and those that bundle natives and extract them on-demand:

• Requiring the native libraries to be bundled with the application manually duplicates code, making it less intuitive to update since multiple things must be changed at once.
• Bundling natives and extracting them on-demand is easy to do for simple classpaths (normal jars, no nesting, no fancy classloaders), however it becomes non-trivial when issues such as nested jars (#10) and OSGi loading (#13) arise.

Solutions prior to this were of the former variety and were difficult to use and deploy, prone to human error, and infrequently updated.

The new official solution borrows code for the simple classpath case from this project, but does not handle more complex classpaths.

This solution is a superset of the official solution; it handles more complex classpaths.

How to Use

1. Add the JCenter repository to resolve the artifacts
2. Add a dependency on com.skaggsm.ortools:ortools-natives-all:8.0.8283 in your build tool of choice
3. Write code:

   // Somewhere before using OR-Tools classes
   OrToolsHelper.loadLibrary();

Before using, ensure the system meets the minimum requirements for installing OR-Tools.

Supported Java Versions

Simple Classpaths

Basic requirements: >= Java 8

Complex Classpaths (Spring, etc.)

Basic requirements: >= Java 11

Confirmed working versions:

• Java 11
  • OpenJDK Runtime Environment 18.9 (build 11.0.7+10)
  • OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.7+10)
  • OpenJDK Runtime Environment GraalVM CE 20.1.0 (build 11.0.7+10-jvmci-20.1-b02)
• Java 12
  • OpenJDK Runtime Environment (build 12.0.2+10)
  • OpenJDK Runtime Environment AdoptOpenJDK (build 12.0.2+10)
• Java 13
  • OpenJDK Runtime Environment (build 13.0.2+8)
  • OpenJDK Runtime Environment AdoptOpenJDK (build 13.0.2+8)
  • Java(TM) SE Runtime Environment (build 13.0.2+8)
  • Likely all versions
• Java 14
  • Likely all versions

Confirmed NOT working versions:

• Java 11
  • Java(TM) SE Runtime Environment 18.9 (build 11.0.7+8-LTS)

More information here: #10.

Details

This library is divided into several modules:

• ortools-loader
  • Handles extracting the relevant binaries from the classpath and loading them for JNI.
• ortools-natives-all
  • Meta-dependency that resolves all possible native dependencies.
• ortools-natives-linux
  • Packages the "Ubuntu 16.04" binary distribution
• ortools-natives-macos
  • Packages the "Mac OS X binary" distribution
• ortools-natives-windows
  • Packages the "Windows with Visual Studio 2019" binary distribution

Native library lifecycle:

1. JVM startup
2. OrToolsHelper.loadLibrary(); called
   • Native binaries are extracted to a temp directory
   • Native binaries are loaded by the system
3. JVM shutdown
   • Native binaries are deleted