Transitive file dependencies in gradle - java

I would like to control which of my dependencies in a multi-project Java build are transitive. My current solution is to set up an "export" configuration in the root project:
allprojects {
configurations {
export {
description = 'Exported classpath'
}
compile {
extendsFrom export
}
}
}
Project A has multiple file dependencies:
dependencies {
compile files('A.jar', 'B.jar')
export files('C.jar')
}
Project B has a dependency on project A, but only C.jar should be on the classpath for compilation, so add:
dependencies {
export project(path: ':A', configuration:'export')
}
This produces the desired results, A.jar and B.jar are not on the class path, but C.jar is on the classpath for compilation.
I am unsure if this is "gradle" way of doing things. To configure transitivity, I would rather specify an attribute or a configuration closure to the dependency entries in project A, instead of using a different "export" configuration.
Is this possible for file dependencies, or is there another way to achieve this?

If I understand your scenario correctly, then yes it's easy to do this. Just add an options closure to the end of the dependency declaration to prevent transitive dependencies (I've changed A,B,C .jar to X,Y,Z because I'm guessing they don't coincide with projects A and B):
// Project A build.gradle
dependencies {
compile(files('X.jar', 'Y.jar')) { transitive = false }
export files('Z.jar')
}
Which would prevent X.jar and Y.jar from being added to the classpath for project B.
Alternatively, and I don't know how well this would work for you and don't really recommend it (just want you to know of the possibilities) you could do this in project B's build.gradle:
configurations.compile.dependencies.find { it.name == "A.jar" }.exclude(jar: it)
configurations.compile.dependencies.find { it.name == "B.jar" }.exclude(jar: it)
Hope that helps.

Related

How to generate all-projects-in-one Gradle project?

I have a gradle monolithic project with too many dependencies.
I'd like to explode it into many sub-projects and publish all sub-projects (build + sources + javadoc) + an extra project being the merge of all sub-projects.
This extra project should be like a virtual artifact with all my projects in a single jar like it is today because I don't want a too big change for my users.
The jar must not include dependencies (it is not an uber-jar) but the resulted pom.xml must contain the dependencies of all sub-projects (the generated pom.xml of the maven artifact must contain all dependencies).
The virtual artifact will include the merge of javadoc and sources too in order to respect Maven Central conventions.
Current state:
Project Main, generate
pom.xml
main.jar
main-sources.jar
main-javadoc.jar
Expected state:
Subproject A, generate
A-pom.xml
A.jar
A-sources.jar
A-javadoc.jar
Subproject B, generate
B-pom.xml
B.jar
B-sources.jar
B-javadoc.jar
virtal-Project Main, generate
pom.xml=A-pom.xml+B-pom.xml
main.jar=A.jar+B.jar
main-sources.jar=A-sources.jar+B-sources.jar
main-javadoc.jar=A-javadoc.jar+B-javadoc.jar
How can I manage it?
We have been in exactly the same situation for some time now. We want to publish a single artifact for our clients to depend on, although internally the product is developed through a few separate component projects. I got it done eventually (with compromises), and here is what I learned:
Merging jars is not as straightforward as it looks like because there could be things like resource files within a jar that are not
always namespace-ed. It is possible that two of your jars have a
resource file with the same name, in which case you will have to
merge the content of those files.
Javadoc is very hard to merge without accessing the original source
files because it has summary pages (index pages).
So my advice would be:
Think twice, maybe what you really want is NOT a single jar, but a single dependency for your clients? These are different. You can easily have a pom only artifact. Depending on this pom only artifact will simply translates transitively into depending on individual artifacts of your component sub projects. To your client, practically, nothing is changed. Spring Boot takes this approach. To do it, you can create an empty java-library project, make all your component projects its api dependency. You don't even need any source code in this project.
If you really want to merge into a single jar, you can try building a fat jar with customization. The customization is not to pull in 3rd party dependencies.
We use the Gradle Shadow plugin for merging jars. Its original purpose was to build a fat jar, which will include all the transitive dependencies. But it also has a special "shadow" configuration, to which you can add dependencies if you want the dependencies to be exported into POM rather than bundled. So what you need to do:
Define a non-transitive configuration (say bundler) to which you will add your sub-project as dependencies. This is going to be the target configuration for the Gradle Shadow plugin.
Define a transitive configuration (bundlerTransitive) that extends from your non-transitive one. This will be manually resolved in order to find the 3rd party dependencies
in your build.gradle, register an afterEvaluate closure, where you find the level two dependencies of the resolved transitive configuration, add them to the shadow configuration. The reason for level-two is that level one dependencies will be your sub-project artifacts.
After all the above, the artifact produced by shadowJar task is the one to be uploaded to maven. You will need to configure the shadowJar task to remove the classifier (which is shadow by default)
Here is a complete example (build.gradle) of bundling vertx-web and all its dependencies within the io.vertx group:
plugins {
id 'java'
id 'maven-publish'
id 'com.github.johnrengelman.shadow' version '5.2.0'
}
group 'org.example'
version '1.0-SNAPSHOT'
repositories {
mavenCentral()
}
configurations {
bundler {
transitive = false
}
bundlerTansitive {
extendsFrom bundler
transitive = true
}
}
dependencies {
bundler "io.vertx:vertx-web:4.0.0"
bundler "io.vertx:vertx-web-common:4.0.0"
bundler "io.vertx:vertx-core:4.0.0"
bundler "io.vertx:vertx-auth-common:4.0.0"
bundler "io.vertx:vertx-bridge-common:4.0.0"
}
shadowJar {
configurations = [project.configurations.bundler]
classifier ''
}
publishing {
publications {
shadow(MavenPublication) { publication ->
project.shadow.component(publication)
}
}
}
project.afterEvaluate {
// this is needed because your sub-projects might have inter-dependencies
def isBundled = { ResolvedDependency dep ->
return configurations.bundler.dependencies.any {
dep.moduleGroup == it.group && dep.moduleName == it.name
}
}
logger.lifecycle '\nBundled artifacts and their 1st level dependencies:'
// level one dependencies
configurations.bundlerTansitive.resolvedConfiguration.firstLevelModuleDependencies.forEach {
logger.lifecycle "+--- ${it.getName()}"
// level two dependencies
it.children.findAll({ ResolvedDependency dep -> !isBundled(dep) })
.forEach { ResolvedDependency dep ->
logger.lifecycle "| +--- ${dep.name}"
project.dependencies.add('shadow', [group: dep.moduleGroup, name: dep.moduleName, version: dep.moduleVersion])
}
}
logger.lifecycle '\nExported Dependencies:'
configurations.shadow.getResolvedConfiguration().getFirstLevelModuleDependencies().forEach {
project.logger.lifecycle "+--- ${it.getName()}"
}
}
For javadoc if you don't care about the index (compromise, as I said), then it is just a jar task with a copy spec:
configurations {
javadoc {
transitive = false
}
}
dependencies {
javadoc 'com.my:component-a:1.1.0:javadoc'
javadoc 'com.my:component-b:1.1.0:javadoc'
javadoc 'com.my:component-c:1.1.0:javadoc'
javadoc 'com.my:component-d:1.1.0:javadoc'
}
task javadocFatJar(type: Jar) {
archiveClassifier.set('javadoc')
from {
configurations.javadoc.collect { it.isDirectory() ? it : zipTree(it) }
}
with jar
}
This cannot be done with maven-publish directly, but one can add individual java-library modules and package each of them with sources and docs. With Gradle this would be a simple jar task, but when the artifacts are publicly available ...such transitive dependencies should better be provided by a meta package; nothing but Maven (Local/Central) dependencies, instead of embedded JARS. In this case, this would be just another module (which obviously would only build after having published the others).
And concerning the concept, that it would require any "merged" JavaDocs ...
https://central.sonatype.org/pages/requirements.html#supply-javadoc-and-sources
While they're referenced (Maven Central) in *.pom, Gradle will be able to find them.
Just use repository mavenLocal() instead of mavenCentral() for testing purposes.

Include pom.xml in Jar with gradle

I'm attempting to include a generated pom.xml in the jar that I'm creating with gradle.
So far, in my parent project, I have
subprojects {
apply plugin: 'maven-publish'
publishing {
publications {
maven(MavenPublication) {
from(components.java)
}
}
}
}
and in the sub-project I have:
tasks.build.dependsOn install
sourceSets {
main {
resources {
srcDirs = [ "src/main/resources", "build/poms" ]
}
}
}
This will generate ./build/poms/pom-default.xml, but it will not add it to the JAR.
Creating a dependency on an earlier phase than build creates circular dependencies (and I don't know whether this is the problem anyway).
Also, I'd like the pom.xml to show up inside META-INF with name pom.xml (not pom-default.xml), so this may not be the right approach anyway.
Somehow I'm thinking it can't be as complicated as this looks?
You should be able to include the POM in your JAR by adding the following to your subprojects closure:
jar {
into("META-INF/maven/${project.group}/${project.name}") {
from generatePomFileForMavenPublication
rename { it.replace('pom-default.xml', 'pom.xml') }
}
}
If you already have a jar closure, you can add it there. This automatically creates a task dependency on the generatePomFileForMavenPublication task, so that the POM file is there when the JAR is created.
The sourceSets part from your question would not be required for this.
(Side note: It would not be strictly necessary to do this at all, because the Maven publish process will publish the POM as an individual artifact anyway.)

How to get sources from parent project as dependency

I want to do something like this:
dependencies {
compile project(':projectA', classifier: 'sources')
}
But I couldn't find such functionallity, I've searched in the documentation but there was nothing besides specifying the classifier on real dependencies.
So it there a way on adding the sources from an parent project inside a Gradle multimodules project as dependency?
I'm not aware that there is a feature from Gradle for that, but there is a workaround:
Add an packageSources to the project which should provide sources
// projectA/build.gradle
project.task("packageSources", type: Jar) {
classifier = 'sources'
from { project.sourceSets.main.allSource }
}
Depend the task on compileJava where you need the sources
// projectB/build.gradle
compileJava.dependsOn tasks.getByPath(':projectA:packageSources')
Add the source as dependency
// projectB/build.gradle
dependencies {
compile files(tasks.getByPath(':projectA:packageSources').archivePath)
}
projectA/build.gradle
configurations {
sources
}
dependencies {
sources sourceSets.main.allSource
}
projectB/build.gradle
dependencies {
compile project(path: ':projectA', configuration: 'sources')
}
See DependencyHandler.project(Map)

Gradle - include class files from one project in another

So I have a multi project setup that looks something like this
Root Project
--> common
--> project1
--> project2
--> 3rd_party_api
So common obviously contains a bunch of code shared across the other projects. Projects 1 and 2 are fine because they are wars and contain the common jar file as a dependency without any issues.
The problem I have is with my 3rd_party_api project. This is quite a small jar file that we will be delivering to other teams so that they can integrate with our code. Most of the java code required is contained in this project folder however there are 3 or 4 classes that are in the common project and need to be included in this library. Because it has to be standalone I need to wrap those classes in the jar file.
I have tried various iterations of srcDirs and source but I can't for the life of me figure out an easy way to do this.
As I've said I've looked at different approaches but my latest attempt looked a bit like this:
project(':api') {
defaultTasks 'jar'
apply plugin: 'java'
sourceSets {
main {
java {
srcDir 'src/main/java'
srcDir fileTree(dir: '../common/src/main/java').matching { include 'com/my/classes/**' }
}
}
dependencies {
compile project(':common')
}
}
This compiles successfully but the extra classes from common are not included in the jar.
Any help would be greatly appreciated.
Thanks Dirk,
Didn't quite work for me but got me thinking about other approaches. I eventually got it to do what I needed using a custom jar task. Something like the following:
defaultTasks 'lib'
dependencies {
compile project(':common')
}
task lib( type: Jar, dependsOn: classes) {
from sourceSets.main.output
from (project(':common').sourceSets.main.output) {
include 'com/myclasses/stuff/**'
include 'com/specificclass/MyClass.class'
}
}
maybe something like:
jar {
baseName = 'yourJarFileName'
from('path/to/your/dir/') {
include 'local/path/from/there/**/*.jar'
}
}
didn't checked this ... so don't blame me if it does not work out of the box ;)
other possibility would be to define your custom sourceSets ... but never tried this either.

How to alter dependencies for a generated artifact?

Gradle 2.3; shadow plugin 1.2.1.
In my build.gradle, I use the shadow plugin in order to repackage a dependency, like such:
shadowJar {
relocate("com.google.common", "r.com.google.common");
}
I also add the shadow jar to the list of artifacts to publish:
artifacts {
archives jar;
archives sourcesJar;
archives javadocJar;
archives shadowJar;
}
However the list of dependencies of the shadow jar still contains all the dependencies of the "normal" jar, even though it has every dependency builtin.
Is this the intended behavior? How can I make the shadow jar exclude this or that dependency?
Here at work we had the same problem and we just put this in a build.gradle of one of our projects:
def installer = install.repositories.mavenInstaller
def deployer = uploadArchives.repositories.mavenDeployer
[installer, deployer]*.pom*.whenConfigured { pom ->
pom.dependencies.retainAll {
it.groupId == 'our.group.id' && it.artifactId == 'some-api'
}
}
This removes all dependencies from the pom.xml except for the dependency on one of our API projects.
(And it is a pretty verbatim copy of an example from the official Gradle documentation.)

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