How to install Google OR-Tools for an IntelliJ project on Windows

[paul-emile Morgades]

Hello,

I'm trying to run the VRP Java examples for Google OR-Tools on Intellij Idea, but I don't know how to install it on Intellij IDEA.

I have found this topic: https://stackoverflow.com/questions/56303148/how-to-install-google-or-tools-for-an-intellij-project-on-macos

This topic implies that I should  update the java.library.path in intelliJ Idea to point to the lib directory.
I have done it, in the Run/Debug configuration with the VM option:
-Djava.library.path=C:\Program Files\or-tools\or-tools_VisualStudio2022-64bit_v9.3.10497\lib\

Nevertheless, I get this error:
java: package com.google.ortools.constraintsolver does not exist.

Do you have any solution?

Thank you in advance.

Regards,

[Kai Müller]

Hey,

have you tried using the maven dependencies?

https://mvnrepository.com/artifact/com.google.ortools

I'm not quite sure if it's yet managed by google, but I think it was once more of a hobby / sideproject of someone.

Many Greetings.

[Laurent Perron]

It's a bit more than a hobby :-)

It delayed the 9.4 release by 1 month just to support arm.

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[paul-emile Morgades]

Thank you for your Answer.

I have tried the maven dependencies.

here is my pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>

<groupId>org.example</groupId>
<artifactId>untitled</artifactId>
<version>1.0-SNAPSHOT</version>
<properties>
<maven.compiler.source>18</maven.compiler.source>
<maven.compiler.target>18</maven.compiler.target>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
</properties>
<dependencies>
<dependency>
<groupId>com.google.ortools</groupId>
<artifactId>ortools-java</artifactId>
<version>9.4.1874</version>
</dependency>
<dependency>
<groupId>com.google.protobuf</groupId>
<artifactId>protobuf-java</artifactId>
<version>4.0.0-rc-2</version>
</dependency>
</dependencies>

</project>

Here is my file hierarchy:

And here is the error I get when I try to execute Vrp:

Exception in thread "main" java.lang.NoClassDefFoundError: com/sun/jna/Platform
    at com.google.ortools.Loader.<clinit>(Loader.java:34)
    at org.example.Vrp.main(Vrp.java:83)
Caused by: java.lang.ClassNotFoundException: com.sun.jna.Platform
    at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
    at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
    at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:521)
    ... 2 more

Do you have any idea ?

Thank you.

[Laurent Perron]

you need jna >= 5.5. from memory

Laurent Perron | Operations Research | lpe...@google.com | (33) 1 42 68 53 00

To view this discussion on the web visit https://groups.google.com/d/msgid/or-tools-discuss/d3442da9-bd1c-4416-b26a-856e3c43889bn%40googlegroups.com.

[Kai Müller]

And if you're running inside a docker container, watch out for the correct base image. I had problems with the alpine image regarding the callback function on the solver.

To view this discussion on the web visit https://groups.google.com/d/msgid/or-tools-discuss/CABcmEeYrrAVMKP%3DJtSShLez%3DeVH9jK4irLck99EfhNLBTCwf%2Bg%40mail.gmail.com.

[paul-emile Morgades]

Thank it  you worked!

The jna jar was missing.

Thank you for the tip on docker.

[Mizux Seiha]

1. Alpine is a libmusl based distro so our manylinux native package published on maven and using glibc will have hard time to work...
workaround: we provide distro specific pre-build on the github release page: https://github.com/google/or-tools/releases/tag/v9.4
e.g. https://github.com/google/or-tools/releases/download/v9.4/or-tools_amd64_alpine-edge_java_v9.4.1874.tar.gz

Otherwise we (I) provide two project template:
* https://github.com/or-tools/maven_or-tools

* an older one (rusty) explaining how to install the jar file in your local maven cache.
https://github.com/or-tools/java_or-tools
note: will try to update it and use an Alpine based docker image.