I have a Maven project that works just fine.
In order to triage an issue, I manually patched a jar to add debug logging and then copied it to the local Maven repo directory. I made subsequent changes to the jar file to add more debugging and did a mvn install:install-file since that seemed more "official".
Note that I did not change the coordinates at all (I know that artifacts are meant to be immutable, but I did not want to change pom.xmls).
My question is: when (if ever) will Maven overwrite this patched jar with the one in the remote Maven repository which is considered the source of truth?
There are only three scenarios in which that jar can be overwritten:
If you delete the jar from your local m2 repository, it will be downloaded from the remote repository the next time you build your maven project.
If you build your maven project with '-U' option. Doing this will force maven to update the dependencies from remote repository.
If you perform an mvn install on the same artifact(updated code) with the same version.
Related
I want to use a project called projectA that I have in a maven repository as dependency of a projectB.
The mvn deploy of projectA is successful (I can see in the repository the projectA-0.0.1-20190902.072951-1.jar, projectA-0.0.1-20190902.072951-1.pom and maven-metadata.xml files), but when I specify the dependency in the pom.xml file of projectB, the project works but it downloads two JARs of projectA from the repository:
- projectA-0.0.1-20190902.072951-1.jar
- projectA-0.0.1-SNAPSHOT.jar and the same issue for every file downloaded by the dependency to this project.
I think that only one JAR is necessary, and I don't know what I need to put maybe in settings.xml or in the pom.xml file of any project to get only one JAR when the dependency is downloaded.
Thank you so much for your help!
In the past it was possible to tell Maven to deploy Non-unique Snapshot Deployments but in Maven 3
... snapshot artifacts will always be deployed using a timestamped version
So:
the files with the timestamps are the one you have deployed to your remote repo (mvn deploy ...) and then downloaded from there as dependencies
the ones with -SNAPSHOT are the result of the local builds (install goal)
If your concern is download traffic - that is not an issue. The -SNAPSHOT ones are not downloaded.
If your concern is disk space then you can have a cron job or use something like Build Helper Maven Plugin to remove old version artifacts from the local repository.
Once I change the repository url and I want to test how this center downloading jars (in local repo I have downloaded jars and I want to delete those jars and restart download).
Does any maven plugin or command support this?
I think you need:
mvn dependency:purge-local-repository
See Purging local repository dependencies
I have a local maven repository and installed a custom artifact. It works if i reference it in other projects. But now i want to use a server for a "own maven repository". If i delete the artifact from the local maven repository, i assumed that the project will not build when i do a maven clean and maven force update dependencies. The artifact cannot be found under .m2/ but Spring Source Tool Suite still can add the artifact to new Java Projects. Create New Java Project -> Edit Pom -> Maven Artifact is added, even if i deleted it from local repository .m2/ . How is this possible and how can i delete it completely, to be able to test if now all dependencies are updated from my server with the .m2/settings.xml configuration?
Your repository is just a directory/file structure. Go to your local repo, find the path (the group id is the path), and delete from the place where you start to see version numbers. When you rebuild, the artifact should be downloaded/replaced from your server/repo.
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.
I am reading up Maven - The complete reference and came across this
Maven assumes that the parent POM is available from the local repository, or available in the parent directory (../pom.xml) of the current project. If neither location is valid this default behavior may be overridden via the relativePath element.
What exactly is meant by local and remote repository for a Maven installation and a project?
A local repository is a local directory structure that caches artifacts downloaded from remote repositories, or those that are manually installed (eg from the command line option).
A remote repository is a web service (defined by a URL) that contains versioned artifacts. This might be as simple as an Apache server, or a full-blown Maven repository, such as Artifactory, that allows uploading, permissions based on a user directory, etc.
http://maven.apache.org/guides/introduction/introduction-to-repositories.html
By default, Maven will source dependencies from, and install dependencies to, your local .m2 repository. This is a precedence rule, and your .m2 acts like a cache where Maven can source dependencies before downloading them remotely. You can bypass this behaviour like so: mvn -U ... (see mvn --help).
Your local .m2 can be found under C:\Users\{user}\.m2 on Windows, or /home/{user}/.m2 on Linux. If you do a mvn install, your project will be locally installed under the said .m2 repository.
A remote repository is a Maven repository, just like your local .m2 repository, hosted for you to source dependencies from, e.g. Maven Central.
Local repository is a repo. Into your local system, when you compile or install project all required dependencies downloaded into your local repo.
When you're working with your project, then Maven first tries to get dependencies from local. If it's not available, then Maven will try to download the dependency from a central repository.
central repo. is a online repo, which is provided by maven itself.