Combining different repositories as a single maven project - maven

I have few standalone projects which are built in sbt and few are in maven.
These projects are available in github as seperate repositories.
Now the task is to keep all these projects into a single repository.
My plan is to keep all these projects as different packages into a single maven project and store this into a single repo. I am using IntelliJ as IDE.
How can I achieve this? Or is there any easy way to achieve this, other than just copying all repos into a single one?
Can we keep both sbt build and maven build file together in one project or do we need to migrate all the sbt builds to maven?
Any leads appreciated!

If you want to combine them into a single Maven repository then obviously you will need to convert Sbt projects into a Maven ones. To convert you may consider using makePom from SBT. See also this SO thread.
Can we keep both sbt build and maven build file together in one project or do we need to migrate all the sbt builds to maven?
You can. In IDE then you will need to choose if you would like to open such project (module) as a Maven or SBT based.

Related

After making a Gradle groovy jar library how to make it re-usable for multiple local projects?

Here I read about how to make a Groovy library .jar ... i.e. pretty much the same as making a Groovy (standalone) project. But I'm not clear what you do then with the resultant .jar...
Say I have two Eclipse "proper"/"standalone" projects (I'm using Groovy for everything) and I want them to share a third Gradle library project of mine as a dependency, which is merely a library of classes... how are my standalone projects expected to find the latest .jar version of the library which they're both using...?
My expectation would be that somehow these versions of the library .jar would have to under GRADLE_USER_HOME (i.e. same location as all other dependency .jars).
Then I would assume that in the build.gradle of both standalone projects you'd have a line like
compile 'mylibrary:mylibrarymodule:3.+'
... of course the first part of these compile directives normally involves a "domain name in reverse" ... and this is normally used by a repository like Maven. How does it work with something which doesn't need to be published?
NB at the time of writing I don't have a Maven account as such and have no idea whether "publication" for re-use of a local common library project like this is essential or not.
Naturally, when I distribute versions of my standalone projects they will need to be packaged up with the library .jar in question.
A link to a how-to for a case like this would be more than welcome: I haven't found it under gradle.org.
If you are developing by yourself, you can use maven-publish plugin to publish your artifacts to local maven repository(you don't have to install maven for this) and on your dependent project you can simply say use mavenLocal repository for dependencies.
If you are on a company, I suggest installing a repository manager and deploy your artifacts to this repository so others can use. You can use their respective plugins to deploy easily. (Gradle Artifactory Plugin, Gradle Nexus Plugin, these are just deployment plugins, you have to setup respository manager to. There are other repository management tools also.) Doing the above process from CI server is the preferred way.
To use latest version of a dependency, you can use Gradle Versions Plugin. If the versioning happen often, using snapshot versions also a possibility.

Is there any easy way to generate mave pom file from ant build

I have a ant build.xml file , how can i directly create a maven pom.xml which is exactly equivalent of build.xml file ? I know that I can create a maven project and move the folder of build.xml to appropriate folder of maven directories, But is there any automated way of doing this ?
ANT and MAVEN are different so there is probably no such complete automation really.
Still there are some attempts to automate it (see: https://github.com/ewhauser/ant2maven/blob/master/ant2maven.groovy and its forked repositories).
Another approach may be to create a pom.xml file and use https://maven.apache.org/plugins/maven-antrun-plugin/ to include the ANT script in it.
The simple answer is no. There is no easy way to generate a POM.
In my opinion switching to Maven is best left to new projects with little or no legacy to defend. In short Maven is a highly opinionated build tool that follows a standardized build workflow. ANT, on the other, ANT is gloriously configurable... resulting in no two builds working the same way :-)
A secondary problem is that few ANT builds properly record the origin and version of their 3rd party dependencies...
In most cases you are better off keeping the existing ANT build logic and introduce dependency managment using a plugin like Apache ivy. This allows an ANT project to properly integrate with a Maven repository infrastructure. This further enables collaboration with other teams using alternative build tools like Maven, Gradle or SBT.
Related answers:
Migrating complex project from Ant to Maven - How to handle unusual folder structures?
Maven or Ivy? Which one is better with a system already in production? And the other differences?

Dependency on non-maven module

The entire java project has an ant build; however couple of module(s) have maven build too.
My new module (maven built, say A) has dependency over an existing module(or simply a folder?, say B) which is being built using ant which just packages the src into jar and drops it inside the project.
Maven build for module A fails (unable to locate moduleB files); Options -
1. Package module B using maven, push to m2_repo
I do not want to go with this option.
Please let me know what are the other options available for the same.
If you have control over the source of all your modules, and if you decided that Maven is your way to go forward, then I recommend to to go all-in as soon as possible. If you do not then you will have continuous problems for the two build strategies to play along. And not only during build time but also at deploy time when it is time to collect all your runtime dependencies. Unless you build one uber-JAR as your only deployable artifact.
If your modules will (almost) always release in sync, then consider using a multi-module project setup.
When I say "all-in" then I do not mean that you have to give up Ant completely. You can use the maven-antrun-plugin to kick of your existing ant builds.
You should also consider running your own repository server, e.g. Nexus, to take full advantage of your maven builds.

How to give deploy dependencies in gradle?

I'm working on multi-project build using gradle. The projects are developed independently ( in svn each project is in a different branch ). Each project is publish to repository and some other project might need one of this published project to be deployed ( in jboss ) before deploying that project. So the idea is to get the publish artifact from that project and deploy without checking out that particular branch.
I want to know how to do this using gradle, (Is it possible to declare a deployment dependency ? )
Thanks in Advance
I recommend to try and use the gradle-arquillian plugin, which may be bundled with the core Gradle distribution at some point. The other option is to script your own solution. If you decide to go with the latter, you only really need to figure out the deployment part, as fetching the artifacts is trivial (see "Working with dependencies" in the Gradle User Guide).

How to make my maven project depend on non maven projects?

I want to create a maven project, which has to depend on a non maven project which in turn depends on 2 other non maven projects. I do not have ownership of any of the other projects and it would not be possible for me to change anything in those projects let alone the structure to conform to the maven structure.
I asked if I could just get jars -- but was told that because of multiple levels of dependency, it would be "difficult" -- although I haven't understood why.
Is this possible or should I just abandon the use of maven to create my project and go with a regular project with jars in the lib folder?
Inxsible
If you can go with a regular project build that means you must have access to the other project's jar files?
It doesn't really matter how the other project builds them, you can still gain more control over your own build process by loading the jars you depend on into a Maven repository.
I'd suggest using one of the following repository managers:
Nexus
Artifactory
Archiva
They'll give you management screens to uploading 3rd party jars, they'll also a more efficient way to use other Maven repositories like Maven Central.
Once you've got your Maven build process working, you could encourage the other projects to automatically publish their versions into your Maven repo.
They could use the ANT tasks provided by the Maven or Apache ivy projects. Worst case you just continue to load their libraries until they see the light :-)

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