How to add external jar?

[jissee]

I am trying to use a video decode library (org.bytedeco) in the mod. The code can be called in the source code and  compiled correctly, but when i enter the game, it throws ClassNotFoundException org.opencv.core.Core and NoClassDefFoundError org/opencv/core/Core. I just implemented 4 libs like this:

    implementation 'org.bytedeco:ffmpeg:5.0-1.5.7'
    implementation 'org.bytedeco:javacpp:1.5.7'
    implementation 'org.bytedeco:javacv:1.5.7'
    implementation 'org.bytedeco:opencv:4.5.5-1.5.7'

And considering the runtime dependency, i also used jarJar:

    implementation(group : 'org.bytedeco', name : 'ffmpeg', version : '[5.0-1.5.7,6.0)' ){
        jarJar.pin(it,'5.0-1.5.7')
    }
    implementation(group : 'org.bytedeco', name : 'javacpp', version : '[1.5.7,1.6)' ){
        jarJar.pin(it,'1.5.7')
    }
    implementation(group : 'org.bytedeco', name : 'javacv', version : '[1.5.7,1.6)' ){
        jarJar.pin(it,'1.5.7')
    }
    implementation(group : 'org.bytedeco', name : 'opencv', version : '[4.5.5-1.5.7,6.0)' ){
        jarJar.pin(it,'4.5.5-1.5.7')
    }

i don't know why the compilation can be correct but when i run the game it contains errors. 

or i need to add external jar libs in other ways...

[warjort]

The libraries you adding in the first example are not mods.  So forge won't load them.

You could of course change them into mods by adding a META-INF/mods.toml to them.

 

JarJar is not something I know a lot about, but I do know you have to enable it in your build.gradle

https://forge.gemwire.uk/wiki/Jar-in-Jar#Using_ForgeGradle_to_generate_a_Jar-In-Jar

Quote

To enable it, you need to call `jarJar.enable()` anywhere in your buildscript

 

Shading is another option mentioned on that wiki link, e.g.

https://imperceptiblethoughts.com/shadow/introduction/