Conditionally include maven dependency locally instead of nexus repository - maven

I have a project A and B. Project B uses project A as a dependency. I am publishing project A to Nexus repository when changes are tested and good to go to Nexus. However I don't want to publish project A to nexus whenever I want to test changes locally.
Is there a way to use project A's changes locally into project B without having it to be read from repository. Some condition that will make maven read project A from local rather than Nexus.
I want to keep project A in common maven dependencies rather than making changes in Maven profiles.

Maybe I am missing some obvious point but I would assume that you can just mvn install project A with a new version and adjust the dependency of A in project B to use that new version. By installing project A it should be available to be used in project B locally because it will be installed into your local Maven repository.
E.g.
In project A's pom.xml
<project>
<name>A</name>
<version>1.1.1-new-version-for-testing</version>
</project>
In project B's pom.xml
<dependencies>
<dependency>
<artifactId>A</artifactId>
<version>1.1.1-new-version-for-testing</version>
</dependency>
</dependencies>

First things first, there is a local repository on your computer that contains all the dependencies (by default in ~/.m2 but you can change that)
You can think about it as a local cache of the dependencies required to work with your own project
When you change the project A you can install the "updated" version by running mvn install on project A.
After that command project B when tested will not try to contact maven repository and will get a version of project A from your local repository.
For SNAPSHOT dependencies, maven once in a day will try to get the later version from Nexus anyway, even if you have a copy in the local repository, because working with snapshots assumes that you're OK with getting daily changes.
But then you have the following choices:
Don't work with SNAPSHOT-s at all. This is something that you shouldn't do anyway in production (I mean, when you release project B, it should contain SNAPSHOT dependencies in its pom)
When you compile project B, assuming you have all the dependencies in the local repository, use mvn <whatever> -o. This -o option means that maven should be run in offline mode, that is it won't attempt to contact a remote repository altogether. (BTW, If you want to do the opposite, which is to forcefully download all new dependencies from Nexus, you can run mvn <whatever> -U

Related

How non maven project can be added as a dependency in maven project

One project A is added in project B as a source.
I want to add in POM.xml of project B.
1-A is non maven project.
2-B is Maven project
How non maven project can be added as a dependency in maven project as a dependency.And I don't want to run it as a separate project and place the jar in local repository.
You need to put the "non-maven-jar" into the local (or a remote) repository. You can either build it and use mvn install:install-file to install it locally (or the deploy plugin to use a remote repository) or you need to change project A into a Maven project.
Technically, it is also possible to include a dependency by a path (<systemPath>), but this is not recommended.

Installation and deployment of maven test-jar

I've discovered the wonderful test-jar facility in Maven: https://maven.apache.org/plugins/maven-jar-plugin/examples/create-test-jar.html
But it may so happen that one project needs to use the test-jar of another project. From https://stackoverflow.com/a/6469256/421049 and experimentation, it would seem that using mvn install does not install the test-jar to the local ~/.m2/repository. So how does one project on my machine use the test jars of another project not in the same aggregate POM?
Yet it would seem from Maven deploy not to upload test jar that deployment of a project to Maven Central does in fact deploy the test-jar? So I can deploy it to Nexus but not install it locally? And if I deploy it to Nexus, will my local project using a dependency of <type>test-jar</type> go find it on Maven Central?
It turns out that maven-jar-plugin does in fact install the test-jar (e.g. foo-1.2.3-tests.jar) in the local Maven repository ~/.m2/repository/.... Wonderful!
My problem is that I had inadvertently configured the maven-jar-plugin to be in a separate profile named release. (I had copied and pasted to the wrong location in my POM.) That's why the test-jar didn't show up in my local repository after a mvn install, and that's why it suddenly showed up later (after I used -P release once in testing), and I thought I had just missed it when I looked the first time.
I move the maven-jar-plugin to the <build> section and everything is working fine: the test-jar gets put into the local maven repository using mvn install.
In my case, I was setting maven.test.skip for a particular build profile. That property actually causes tests to not be compiled/installed, thus also preventing their deploy. The solution was to set the skipTests property instead.

IntelliJ uses snapshots with timestamps instead of -SNAPSHOT to build artifact

I have a project with snapshot dependencies. For simplification let's say that there is an project A which depends on library B-0.1-SNAPSHOT.
A depends on B
B resides within Nexus repository as a snapshot. I can see that it is stored with timestamp so the actual name in Nexus is something like: B-0.1-20141126.171716-67.jar
After executing:
mvn clean install -U
on project A, dependency B is downloaded from Nexus to my local repository. There I can find two jars of library B:
B-0.1-SNAPSHOT.jar
B-0.1-20141126.171716-67.jar
So far so good.
After maven build is complete I can see that B-0.1-SNAPSHOT.jar was taken to build A artifact (.war file)
I also have project A imported to IntelliJ as a maven project. There I run it on Tomcat. Project is build by IntelliJ and B-0.1-20141126.171716-67.jar is added to .war file.
At the end I have .war with both B-0.1-SNAPSHOT.jar and B-0.1-20141126.171716-67.jar within WEB-INF/lib directory.
For me is seems like a bug in IntelliJ because B-0.1-SNAPSHOT.jar should be taken from local maven repository... not the timespamped version. Is there any way to force IntelliJ to act propeply?
Maven version is 3.2.3, IntelliJ 14.0.1 (but the same behavior was on 13).
I was faced to the same problem today, and I found how to disable this feature.
F4 on your module, and go to artifacts then select the name of your artifact webapp:exploded and check the show contents radio at the bottom of the frame.
Go to WEB-INF/lib and search for your dependecy B-0.1-SNAPSHOT.jar and expand the line you will see a compile output folder in it, just remove it, then repackage and run, you will now only have the B-0.1-SNAPSHOT.jar and the one with the timestamp should be gone.
The downside of this is that you will have to make sure to mvn install your B module before running the A module within IntelliJ, because IntelliJ won't package your dependency and bundle it with the code you've just edited but not installed in your local maven repository.

How to install a Maven/Gradle project along with all its dependencies to a local repository?

I have a Gradle project that depends on several open-source projects up on Maven Central. I'd like to install the project – along with all its direct and transitive dependencies – to my local maven repository, so that I could later zip it all up and put it on offline machines.
How do I do it with Gradle/Maven?
mvn dependency:get plugin will fetch the artifact with all dependencies to the local repository.
I had also developed a plugin to install remote artifacts to a local machine.
If you want to later ZIP up your project w/ dependencies and move them to a different machine, you could try Maven's appassembler plugin. It collects all dependencies and creates a launcher, all in the target folder, ready for deployment.
But note, this, by default, creates a flat directory structure with all dependencies, it doesn't preserve the Maven format. It also has the option to create a repository.

Unconventional dependency name in maven

I have a few dependencies like this. For example : jdic
In my pom.xml, I defined a dependency
<dependency>
<artifactId>jdic</artifactId>
<groupId>jdic</groupId>
<version>0.8.6</version>
</dependency>
And I have a remote repository (internal server): eg http://repo/thirdparty/
And jdic can be found in http://repo/thirdparty/jdic/jar/jdic.jar
As you notice, the naming is not conventional groupId:artifactId:version, instead its just jdic.jar
so when I run maven compile
mvn clean compile
maven tells me that it cannot resolve dependencies.
I'm aware that we can just download those jars to the local repository .m2/repository and run
mvn compile (ie without clean)
and it the jar will not be a problem. But is there any other way that I can make it retrieve from the remote despite its unconventional name and lack of metadata/pom info for those dependencies?
I already have a mirror to this internal repository that overrides the central
You could install the jdic in your internal/mirror repository with the version (jdic-0.8.6.jar).
If you are using a repository manager and you uploaded the jar to it, it would automagically create a pom for it as well as ensure the dependency was created with version, as per maven convention.
A remote Maven repository is NOT any web server putting files in any way you want. There are lots of convention to follow. One of them is the way to represent the version (which is one essential element of an artifact). With your "remote repository" it is clear that there is no way Maven can find the artifact.
Setup a real Maven remote repository to host such files. You can have a look in Nexus and Artifactory.

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