Develop Reference

Maven add external jar

I would like to add the following jar
gson-extras-1.0-SNAPSHOT.jar
the jar structure is the following
looking at the manifest the version is
Manifest-Version: 1.0
the pom is the following
<repositories>
<repository>
<id>grupoicarep</id>
<url>file:///C:/stix/stix_ica/stix2/lib/</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>com.google.gson</groupId>
<artifactId>typeadapters</artifactId>
<version>0.1</version>
</dependency>
but it shows the following error:
Failed to execute goal on project stix2: Could not resolve dependencies for project es.grupoica:stix2:jar:0.0.1-SNAPSHOT: Failure to find com.google.gson:typeadapters:jar:0.1 in file:///C:/stix/stix_ica/stix2/lib/ was cached in the local repository, resolution will not be reattempted until the update interval of grupoicarep has elapsed or updates are forced -> [Help 1]
[ERROR]
I have tried many combinations but I am just guessing and not getting the right result
I don´t know what I am doing wrong
many thanks in advance
Ana

Use below dependency to include the jar available in the local machine to maven.
<dependency>
<groupId>groupid</groupId>
<artifactId>artifactid</artifactId>
<version>1.0</version>
<scope>system</scope>
<systemPath>${basedir}\lib\JAR_NAME.jar</systemPath>
</dependency>

How do I include a maven package that has invalid/outdated POM?

I want to use a package named sourcemap in my project. It's not available in maven central, but in Atlassian's public maven repository. I therefore set up my pom.xml like this:
<repositories>
<repository>
<id>atlassian</id>
<name>Atlassian</name>
<url>https://packages.atlassian.com/content/repositories/atlassian-public/</url>
</repository>
</repositories>
<dependencies>
<dependency>
<groupId>com.atlassian.sourcemap</groupId>
<artifactId>sourcemap</artifactId>
<version>1.7.7</version>
</dependency>
</dependencies>
Now, the POM file for sourcemap references another POM file from a package named public-pom:
<!-- POM for sourcemap (NOT my pom.xml!) -->
<parent>
<groupId>com.atlassian.pom</groupId>
<artifactId>public-pom</artifactId>
<version>3.0.84</version>
</parent>
The problem: the POM file references version 3.0.84 of public-pom, but Atlassian's repo no longer provides 3.0.84. Currently, the oldest available version of public-pom is 5.0.0, as you can see here. Because of this, maven complains when I attempt to build the project:
Could not find artifact com.atlassian.pom:public-pom:pom:3.0.84 in atlassian (https://packages.atlassian.com/content/repositories/atlassian-public/)
How can I fix the POM and use this package in my project?

Mvnrepository lists com.atlassian.pom:public-pom:pom:3.0.84 but when selecting the link to it:
status: 404
message: "Could not find resource"

How to upload maven plugin to Github packages?

Consider I have a maven plugin project and I want to publish it to Github's public maven repository called "Github Packages". I've done everything by instruction and for normal projects everything works fine out of the box. But for maven plugin projects with packaging=maven-plugin the instruction doesn't work.
In build log I see something like this:
[WARNING] Could not transfer metadata repo-name/maven-metadata.xml
from/to github (https://maven.pkg.github.com/user-name/repo-name):
Failed to transfer file:
https://maven.pkg.github.com/user-name/repo-name/group-id/maven-metadata.xml.
Return code is: 422 , ReasonPhrase:Unprocessable Entity.
It seems the maven deploy plugin needs maven-metadata.xml in the group-id's root, but can't find it and no one puts it there. How to solve this problem?
I use Apache Maven 3.3.9, and use the command:
mvn clean deploy
--Addition: example of pom file I'm using:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<repositories>
<repository>
<id>central</id>
<url>https://repo1.maven.org/maven2</url>
<releases>
<enabled>true</enabled>
</releases>
<snapshots>
<enabled>true</enabled>
</snapshots>
</repository>
<repository>
<id>github</id>
<name>GitHub my_repo Apache Maven Packages</name>
<url>https://maven.pkg.github.com/my_nick/my_repo</url>
</repository>
</repositories>
<version>1.0.0</version>
<groupId>x</groupId>
<artifactId>some-plugin</artifactId>
<packaging>maven-plugin</packaging>
<dependencies>
<dependency>
<groupId>x</groupId>
<artifactId>my-dependency</artifactId>
<version>1.0.0</version>
</dependency>
<dependency>
<groupId>com.github.javaparser</groupId>
<artifactId>javaparser-core</artifactId>
<version>3.15.12</version>
</dependency>
<dependency>
<groupId>org.apache.maven.plugin-tools</groupId>
<artifactId>maven-plugin-annotations</artifactId>
<version>3.6.0</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.maven</groupId>
<artifactId>maven-plugin-api</artifactId>
<version>3.6.3</version>
</dependency>
<dependency>
<groupId>org.apache.maven</groupId>
<artifactId>maven-core</artifactId>
<version>3.6.3</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-plugin-plugin</artifactId>
<version>3.6.0</version>
</plugin>
</plugins>
</build>
</project>

Unfortunately I haven't found the right answer to my question, it seems that for now it's impossible to add Maven plugins to Github Packages.
However I found a workaround which uses S3 as a repository backend, so you don't need heavyweight solutions like Nexus or JFrog. You can read this and this on how to do it.

I had the same problem 422 from server: Unprocessable Entity when publishing Maven artifacts from GitHub Actions to GitHub Packages. The reason was that the corresponding tag for the uploaded artifact didn't exist yet.
The error message may be better in this case.

If you have already uploaded the artifact to the GitHub Packages then it means you have configured everything right.
I suppose the real reason for the 422 error is that you are trying to upload the same artifact with the same version that already was uploaded. And if it is not a SNAPSHOT version then the repository should deny replacing it so it behaves correctly.
I got the same error when trying to redeploy the already deployed package:
Failed to execute goal org.apache.maven.plugins:maven-deploy-plugin:2.7:deploy (default-deploy) on project MavenPluginForGithub:
Failed to deploy artifacts: Could not transfer artifact ru.dmochalov:SampleMavenPluginForGithub:jar:1.0.3 from/to github (https://maven.pkg.github.com/dmochalov/hello-world):
Failed to transfer file: https://maven.pkg.github.com/dmochalov/hello-world/ru/dmochalov/SampleMavenPluginForGithub/1.0.3/SampleMavenPluginForGithub-1.0.3.jar.
Return code is: 422, ReasonPhrase: Unprocessable Entity. -> [Help 1]
How to fix?
Is suppose you have two options:
Increment the version <version>1.0.0</version> of the plugin from 1.0.0 to 1.0.1. Consider using 1.0.1-SNAPSHOT versions if the plugin is unstable and under development. GitHub allows redeploying artifacts with SNAPSHOT versions. So you could always redeploy it when developing.
Delete the package from the repo. You can do it only for packages in a private repository.
422 error vs 401 error
I suppose that there is not accepted specification or standardization for error codes and different repositories behave differently. For example, the Maven Central repository replies with 401 error when attempting to replace the already deployed version.
Why GitHub decided to use 422 is a mystery. There is an answer in the community forum but without proper explanation.

Here's the official github link for how to do exactly that. However, since this doesn't seem to be of much help, here's a link to a gradle forum question that should help you with this. Best of luck!

How to use de.entropia.can package in pom.xml file

I'm trying to use this github repo: https://github.com/entropia/libsocket-can-java in pom.xml file. I couldn't find any maven dependency for this github repo. I added jitpack repository and maven dependency to pom file by following this link: https://jitpack.io/p/entropia/libsocket-can-java. Here is my code:
<repositories>
<repository>
<id>jitpack.io</id>
<url>https://jitpack.io</url>
</repository>
</repositories>
<dependency>
<groupId>com.github.entropia</groupId>
<artifactId>libsocket-can-java</artifactId>
<version>4433bb7</version>
</dependency>
where 4433bb7 is the latest commit number. I get this error when I try to build:
Missing artifact com.github.entropia:libsocket-can-java:jar:4433bb7
Could not resolve dependencies for projec: Failure to find com.github.entropia:libsocket-can-java:jar:4433bb7 in https://jitpack.io was cached in the local repository, resolution will not be reattempted until the update interval of jitpack.io has elapsed or updates are forced -> [Help 1]
I tried with bundle versions: 0.1.0, 1.0.0 still no luck. Please help me to resolve this issue. Thank you all in advance.

Seems issue with the specific version. try latest snapshot:
<dependency>
<groupId>com.github.entropia</groupId>
<artifactId>libsocket-can-java</artifactId>
<version>master-SNAPSHOT</version>
</dependency>

How to add Maven dependencies from different repositories

For example, let's say I have a Maven build file that has dependencies located in two different repositories:
<repository>
<id>id1</id>
<name>id1</name>
<url>http://localhost/mavenRepo/repository1</url>
</repository>
<repository>
<id>id2</id>
<name>id2</name>
<url>http://localhost/mavenRepo/repository2</url>
</repository>
With one dependencies from the first repository and the other from the second repository. How can I do this?

Just list all the dependencies in your <dependencies> section, and Maven will contact each repository in turn (including your local repository) to find them.
A POM file has no concept of "get these dependencies from this repository and get these dependencies from that repository".

How can you do what? What is the problem? Just add the dependencies and Maven will try to resolve them from central repository and then fallback on the next declared repository if not found and so on.