DependencyDownload

A library to download, relocate & load dependencies during runtime for Maven dependencies for JVM applications. There is also a Gradle plugin to generate a metadata file, to avoid having to define the dependencies in code.

Uses jar-relocator for relocations during runtime
Looking for something to use with Minecraft? Check out MinecraftDependencyDownload

Dependency

repositories {
    mavenCentral()
}

dependencies {
    implementation 'dev.vankka:dependencydownload-runtime:2.0.0'
}

Snapshots

repositories {
    maven {
        url 'https://central.sonatype.com/repository/maven-snapshots/'
    }
}

dependencies {
    implementation 'dev.vankka:dependencydownload-runtime:2.0.1-SNAPSHOT'
}

Usage

DependencyManager manager = new DependencyManager(DependencyPathProvider.directory(Paths.get("cache")));
manager.addDependencies(new StandardDependency("com.example", "examplepackage", "1.0.0", "<hash>", "SHA-256"));
manager.addRelocations(new Relocation("com.example", "relocated.com.example"));

Executor executor = Executors.newCachedThreadPool();

// All of these return CompletableFuture it is important to let the previous step finishing before starting the next
manager.downloadAll(executor, Collections.singletonList(new StandardRepository("https://repo.example.com/maven2"))).join();
manager.relocateAll(executor).join();
manager.loadAll(executor, classpathAppender).join(); // ClasspathAppender is a interface that you need to implement to append a Path to the classpath

Gradle plugin

plugins {
    id 'dev.vankka.dependencydownload.plugin' version '2.0.0'
}

dependencies {
    runtimeDownload 'some:dependency:x.y.z'
    runtimeDownloadOnly 'some.other:dependency:x.y.z'
}

jar.dependsOn generateRuntimeDownloadResourceForRuntimeDownloadOnly, generateRuntimeDownloadResourceForRuntimeDownload

This would generate two files runtimeDownloadOnly.txt and runtimeDownload.txt

ShadowJar support

shadow is supported to include the relocations in the generated metadata files

Loading dependencies from a plugin generated file

DependencyManager manager = new DependencyManager(DependencyPathProvider.directory(Paths.get("cache")));
manager.loadResource(DependencyDownloadResource.parse(getClass().getResource("runtimeDownloadOnly.txt")));

Customizing

import dev.vankka.dependencydownload.task.GenerateDependencyDownloadResourceTask

task generateResource(type: GenerateDependencyDownloadResourceTask) {
    configuration = project.configurations.runtimeDownload
    includeRelocations = true
    hashingAlgorithm = 'SHA-256'
    file = 'dependencies.txt'
}

Download jar-relocator during runtime

Bring the jar minifying to the next extreme

import dev.vankka.dependencydownload.task.GenerateDependencyDownloadResourceTask
plugins {
    id 'dev.vankka.dependencydownload.plugin' version '2.0.0'
}

configurations {
    jarRelocator
}

repositories {
    mavenCentral()
}

dependencies {
    implementation('dev.vankka:dependencydownload-runtime:2.0.0') {
        exclude module: 'jar-relocator'
    }
    jarRelocator 'me.lucko:jar-relocator:1.4'
}

task generateJarRelocatorResource(type: GenerateDependencyDownloadResourceTask) {
    configuration = project.configurations.jarRelocator
}
processResources.dependsOn generateJarRelocatorResource

DependencyManager manager = new DependencyManager(DependencyPathProvider.directory(Paths.get("cache")));
manager.loadResource(DependencyDownloadResource.parse(getClass().getResource("jarRelocator.txt")));

Executor executor = Executors.newCachedThreadPool(2);

manager.downloadAll(executor, Collections.singletonList(new StandardRepository("https://repo.example.com/maven2"))).join();
manager.loadAll(executor, classpathAppender).join();
// now jar-relocator is in the classpath and we can load (and relocate) dependencies from a regular configuration