Some background:
I have copied the master branch of an external github repository, not owned by me, into a personal repository
This repo contains a Java project and uses Maven for building and compilation
The group ID defined in all pom.xml files is org.mylibrary (let's assume)
When deploying to Artifactory, the deployment is done to myrepo/org/mylibrary/...
I'd like to deploy instead to:
myrepo/org/myorganization/mylibrary
but I would like to avoid editing all the pom.xml files, and replacing all lines containing:
<groupId>org.mylibrary</groupId>
with:
<groupId>org.myorganization.mylibrary</groupId>.
I'm configuring the deployment via the distributionManagement element:
<distributionManagement>
<repository>
<name>releases</name>
<id>deployment.credentials</id>
<url>https://artifactory.lab.myorg.org/artifactory/myrepo</url>
</repository>
</distributionManagement>
What's a clean way of solving this? Replacing the groupId definition in all pom.xml files does the trick, but, as said, that's something I want to avoid.
Thanks!
When deploying to any repository, Artifactory utilizes the layout that is configured for this repository. By default, for Maven repositories, Artifactory uses the "maven-default" layout.
I would recommend you to first add your requested layout and then configure your repository with the newly created layout.
I hope this information is found helpful.
org.apache.maven.plugin.PluginResolutionException: Plugin org.apache.maven.plugins:maven-resources-plugin:2.5 or one of its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.maven.plugins:maven-resources-plugin:jar:2.5
at org.apache.maven.plugin.internal.DefaultPluginDependenciesResolver.resolve(DefaultPluginDependenciesResolver.java:129)
at org.eclipse.m2e.core.internal.project.registry.EclipsePluginDependenciesResolver.resolve(EclipsePluginDependenciesResolver.java:48)
at org.apache.maven.plugin.internal.DefaultMavenPluginManager.getPluginDescriptor(DefaultMavenPluginManager.java:142)
at org.apache.maven.plugin.internal.DefaultMavenPluginManager.getMojoDescriptor(DefaultMavenPluginManager.java:261)
at org.apache.maven.plugin.DefaultBuildPluginManager.getMojoDescriptor(DefaultBuildPluginManager.java:185)
at org.apache.maven.lifecycle.internal.DefaultLifecycleExecutionPlanCalculator.setupMojoExecution(DefaultLifecycleExecutionPlanCalculator.java:152)
at org.eclipse.m2e.core.internal.embedder.MavenImpl.setupMojoExecution(MavenImpl.java:386)
at org.eclipse.m2e.core.internal.project.registry.ProjectRegistryManager.setupMojoExecution(ProjectRegistryManager.java:865)
at org.eclipse.m2e.core.internal.project.registry.MavenProjectFacade.getMojoExecution(MavenProjectFacade.java:355)
at org.eclipse.m2e.core.project.configurator.AbstractCustomizableLifecycleMapping.getBuildParticipants(AbstractCustomizableLifecycleMapping.java:66)
at org.eclipse.m2e.core.project.configurator.AbstractLifecycleMapping.configure(AbstractLifecycleMapping.java:87)
at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration(ProjectConfigurationManager.java:414)
at org.eclipse.m2e.core.internal.project.ProjectConfigurationManager.updateProjectConfiguration(ProjectConfigurationManager.java:351)
at org.eclipse.m2e.core.ui.internal.UpdateMavenProjectJob.runInWorkspace(UpdateMavenProjectJob.java:74)
at org.eclipse.core.internal.resources.InternalWorkspaceJob.run(InternalWorkspaceJob.java:38)
at org.eclipse.core.internal.jobs.Worker.run(Worker.java:54)
Caused by: org.sonatype.aether.resolution.ArtifactDescriptorException: Failed to read artifact descriptor for org.apache.maven.plugins:maven-resources-plugin:jar:2.5
at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.loadPom(DefaultArtifactDescriptorReader.java:296)
at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.readArtifactDescriptor(DefaultArtifactDescriptorReader.java:186)
at org.sonatype.aether.impl.internal.DefaultRepositorySystem.readArtifactDescriptor(DefaultRepositorySystem.java:279)
at org.apache.maven.plugin.internal.DefaultPluginDependenciesResolver.resolve(DefaultPluginDependenciesResolver.java:115)
I have read where many people were able to solve this by:
Deleting the folder from the local repository and letting it re-download it (this did not work)
By configuring eclipse to target your maven installation instead of the embedded one as described here (this did not work)
Could not calculate build plan :artifact org.apache.maven.plugins:maven-resources-plugin:pom:2.4.3 is not available in the local repository
I am new to Maven so please excuse any of my ignorance.
This project is working on another machine, and just pulled it down from the repository on this one, with the same version of eclipse and m2e plugin installed. I have been fooling with this for over 10 hours now and it is driving me nuts (Maven has been nothing but headaches for me so far...)
EDITS
After looking closer I did notice that it is not downloading the .jar files into the local repository... I am not sure if that is something obvious...
I am not given the option to add Maven Dependencies to the build path.
I had the exact same problem.
[ERROR] Plugin org.apache.maven.plugins:maven-resources-plugin:2.5 or one of its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.maven.plugins:maven-resources-plugin:jar:2.5: Failure to find org.apache.maven.plugins:maven-resources-plugin:pom:2.5 in http://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced -> [Help 1]
...
Had maven 3.0.5, eclipse Kepler with JBoss Dev Studio 7 installed. Computer sitting on internal network with proxy to the internet. Here's what I did.
0. Check the maven repositiory server is up
1. Check Proxy is set up and working
First I thought it was a proxy problem, I made sure that maven settings.xml contained the proxy settings (settings.xml can exist in two places one in MAVEN_HOME. The other in %userprofile%.m2\ with the later having higher precedence):
<proxy>
<id>optional</id>
<active>true</active>
<protocol>http</protocol>
<username>optional-proxyuser</username>
<password>optional-proxypass</password>
<host>proxy.host.net</host>
<port>80</port>
<nonProxyHosts>local.net|some.host.com</nonProxyHosts>
</proxy>
and checked that the proxy is working by trying to telnet to it:
telnet [proxy] [port number]
2. Check not Eclipse Issue
ran 'mvn compile' at command line level outside of eclipse - same issue.
If 'mvn compile' worked. But it doesn't work using the maven plugin in eclipse, see Maven plugin not using eclipse's proxy settings
3. Check not Cache Issue
Deleted all contents in my local maven repository. (Default location: ~/.m2/repository) And then reran maven - same issue came up.
4. What worked for me
Automatically download & install missing plugin:
By declaring the missing plugin in the POM file build section for pluginManagement Maven will automatically retrieve the required plugin. In the POM file, add this code for the version of the plugin you require:
<build>
<pluginManagement>
<plugins>
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>2.7</version>
</plugin>
</plugins>
</pluginManagement>
</build>
Manually install missing plugin:
I went to http://mvnrepository.com/artifact/org.apache.maven.plugins/maven-resources-plugin/2.5 and downloaded maven-resources-plugin-2.5.jar and maven-resources-plugin-2.5.pom . Copied it directly into the maven repository into the correct folder ( ~/.m2/repository/org/apache/maven/plugins/maven-resources-plugin/2.5) and reran 'mvn compile'. This solved the problem.
Edit1
Following this I had another two problem with 'mvn install':
The POM for org.apache.maven.plugins:maven-surefire-plugin:jar:2.10 is missing, no dependency information available
The POM for org.apache.maven.plugins:maven-install-plugin:jar:2.3.1 is missing, no dependency information available
I approached this problem the same way as above, downloading from http://mvnrepository.com/artifact/org.apache.maven.plugins/maven-surefire-plugin/2.10 and http://mvnrepository.com/artifact/org.apache.maven.plugins/maven-install-plugin/2.3.1
I had the exact same problem and since I read somewhere that the error was caused by a cached file, I fixed it by deleting all the files under the .m2 repository folder.
The next time I built the project I had to download all the dependencies again but it was worth it - 0 errors!!
Couple of things to try:
Doublecheck the location of the local artifact repo configured in your settings.xml file (at the following location {your home folder}/.m2/settings.xml). Are you sure the local repo is where you think it is? (Yes, a mistake I've made in the past...)
Remove entire contents of artifact repo on the new build machine (or at least anything related to Maven). You mentioned doing some artifact repo cleanup but I'm not sure what directory(ies) you removed. I've run into weird issues like these when a jar was corrupted.
Make sure you have enough disk space/quota for the local artifact repo. I have run into weird issues when I didn't have a large enough quota to hold all the artifacts, likely caused by partially downloaded jar files.
Try running with plain Maven on the command line; take Eclipse and m2e out of the equation. mvn -U dependency:resolve should do it. The -U forces Maven to download no matter what your repository update policies are. Add -X to get detailed debug logging.
Copy settings.xml from MAVEN_HOME\conf\ to USER_HOME.m2. Add proxies (if needed) in case you are behind a proxy server.
Follow easy steps to resolved the below issue:
Could not calculate build plan: Plugin org.apache.maven.plugins:maven-resources-plugin:2.5 or one of its dependencies could not be resolved: Failed to read artifact description for org.apache.maven.plugins:maven-ar-plugin:ar:2.4 in eclipse
Solution:
Step1:
Step2:
Issue solved ☺
i faced the same issue while using eclipse kepler and maven version 3.2,
while building the project, it showed me the same error in eclipse
there are two versions (2.5 and 2.6) of plugin under
.m2/repository/org/apache/maven/plugins/maven-resources-plugin/
i removed 2.5 version then it worked for me
My problem was the location of the config file.
In eclipse settings (Windows->preferences->maven->User Settings) the default config file for maven points to C:\users\*yourUser*\.m2\settings.xml. If you unzip maven and install it in a folder of your choice the file will be inside *yourMavenInstallDir*/conf/, thus probably not where eclipse thinks (mine was not). If this is the case maven won't load correctly. You just need to set the "User Settings" path to point to the right file.
It appears that there can be a lot of different causes for this issue. I experienced it after installing a new version of Eclipse (Luna). Command-line maven worked fine, but Eclipse had build issues.
I use a Certificate Authority in my JRE. This is important because this provides my authentication when downloading Maven resources. Even though my project was pointing to the appropriate JRE inside of Eclipse - Eclipse was running using a different JRE (this is apparent looking at the Java process properties in Windows task manager). My solution was to add the following in my eclipse.ini
and explicitly define the JRE I want to use.
-vm
C:\Program Files\Java\jdk1.7.0_51\bin\javaw.exe
You should check Force Update Snapshots/Releases when updating project with maven.It worked for me :-).
Try to delete all dirs in /usr/share/maven-repo - of course then maven will die so you must re-install and try again. In my case re-install from maven ver.3. to maven2 with deleting all repositories helped.
I tried by deleting all from .m2 but that didn't help.
Some files where missing at your local repository. Usually under ${user.home}/.m2/repository/
Neets answer solves the problem. However if you dont want do download all the dependencies to your local repository again you could add the missing dependency to a project of yours and compile it.
Use the maven repository website to find the dependency.
In your case http://mvnrepository.com/artifact/org.apache.maven.plugins/maven-resources-plugin/2.5 was missing.
Copy the listed XML to the pom.xml file of your project. In this case
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>2.5</version>
</dependency>
Run mvn compile in the root folder of the pom.xml. Maven will download all missing dependencies. After the download you can remove the added dependency.
Now you should be able to import the maven project or update the project without the error.
What I found out is that while m2e is looking for v2.5 by default, my local repo has 2.6 and no 2.5.
Without going into investigation of how this came about
simply adding the dependency to pom solved the problem
<dependency>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-resources-plugin</artifactId>
<version>2.6</version>
</dependency>
This can be removed after running a build once
his issue is happening due to change of protocol from http to https for central repository. please refer following link for more details. https://support.sonatype.com/hc/en-us/articles/360041287334-Central-501-HTTPS-Required
In order to fix the problem, copy following into your pom.ml file. This will set the repository url to use https.
<repositories>
<repository>
<snapshots>
<enabled>false</enabled>
</snapshots>
<id>central</id>
<name>Central Repository</name>
<url>https://repo.maven.apache.org/maven2</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<releases>
<updatePolicy>never</updatePolicy>
</releases>
<snapshots>
<enabled>false</enabled>
</snapshots>
<id>central</id>
<name>Central Repository</name>
<url>https://repo.maven.apache.org/maven2</url>
</pluginRepository>
</pluginRepositories>
A more subtle reason for this could be a Settings.xml file which has a space in the first line before the doctype
Hopefully I'm not late for the party.
Encountered this using Eclipse Kepler and Maven 3.1.
The solution is to use a JDK and not a JRE for your Eclipse project. Make sure to try maven clean and test from eclipse just to download missing jars.
I had the same problem but with an other cause. The solution was to deactivate Avira Browser Protection (in german Browser-Schutz). I took the solusion from m2e cannot transfer metadata from nexus, but maven command line can. It can be activated again ones maven has the needed plugin.
Most people will tell you to check your proxy settings or delete and re-add artifacts, but I will stay away from that and give another suggestion in case that doesn't turn out to be your problem. It could be your mirror settings.
If you use maven at the office then there's a good chance maven is configured to look for your company's internal maven repository. If you're doing some work from home and you are not connected to the network this could be the problem. An obvious solution might be VPN to the office to get visibility to this repo. Another way around this is to add another mirror site to your /User/.m2/settings.xml file so if it fails to find it on your office network it will try public repo.
<mirror>
<id>Central</id>
<url>http://repo1.maven.org/maven2</url>
<mirrorOf>central</mirrorOf>
<!-- United States, St. Louis-->
</mirror>
For other maven repositories take a look here: http://docs.codehaus.org/display/MAVENUSER/Mirrors+Repositories
In my case I'm using an external maven installation with m2e. I've added my proxy settings to the external maven installation's settings.xml file. These settings haven't been used by m2e even after I've set the external maven installation as default maven installation.
To solve the problem I've configured the global maven settings file within eclipse to be the settings.xml file from my external maven installation.
Now eclipse can download the required artifacts.
After entering your proxy settings in settings.xml
<proxies>
<!-- proxy
| Specification for one proxy, to be used in connecting to the network.
| -->
<proxy>
<id>optional</id>
<active>true</active>
<protocol>http</protocol>
<username>DOMAIN\YOURID</username>
<password>123456</password>
<host>proxy.company.com</host>
<port>8080</port>
<nonProxyHosts>local.net|some.host.com</nonProxyHosts>
</proxy>
</proxies>
Check whether the below tag is having the value false in settings.xml
<offline>false</offline>
This helped me.
In addition to what #JackDev replies, what also solved my problem was to
1) Install the jdk under directory with no spaces:
C:/Java
Instead of
C:/Program Files/Java
This is a known issue in Windows. I fixed JAVA_HOME as well
2) Install maven as in Java case, under C:/Maven. Fixed the M2_HOME accordingly.
3) I java 7 and java 8 on my laptop. So I defined the jvm using eclipse.ini. This is not a mandatory step if you don't have -vm entry in your eclipse.ini. I updated:
C:/Java/jdk1.7.0_79/jre/bin/javaw.exe
Instead of:
C:/Java/jdk1.7.0_79/bin/javaw.exe
Good luck
If you've configured a repository in your maven's settings.xml, check if you've access to it.
When I had this problem, there were enterprise repositories configured in settings.xml but I was out of the company.
JackDev's option 3 works for me after I changed the default repository to another folder.
Below is what I see after M2E plugin automatically download the maven-resources-plugin-2.6. Maybe this could give you some hint if you want to take the manual approach. The necessary files can be downloaded from here: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-resources-plugin/2.6/
If you have a proxy, you also have to clear SOCKS in
Window > Preferences > Network Connections.
I was getting the same issue.
I just installed the m2e (Maven2Eclipse)plugin from below site:
http://www.eclipse.org/m2e/
Eclipse>Help>Install New Software>Available Software Sites>Add
Name: m2e (any name is OK)
Location:m2e - http://download.eclipse.org/technology/m2e/releases/
Under Install Window> Work with:
Select this new location and Add all the plugins that appear. Eclipse restart and it was running properly with no previous errors.
If your working at a company, they may be preventing you from downloading outside software and installing it. You may need to install the plugins manually or repoint to an internal mirror repository.
Try downloading a different version of maven.
I had the same problem with maven 3.5.2 , I solved my problem just downloading maven 3.0.4
Very old stuff.
Got it solved fixing the localRepository in settings.xml.
This file was copied from my other computer and the path of the .m2 repository wasn't the same.
<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
<localRepository>C:\Users\foo\.m2</localRepository>
</settings>
I could solve the issue with the following steps
Install Maven separately
https://www.mkyong.com/maven/how-to-install-maven-in-windows/
Set the external Maven installation in Eclipse
3. Set the proxy in settings.xml in Maven installation
(C:\path\apache-maven-3.6.0\conf)
<proxy>
<id>optional</id>
<active>true</active>
<protocol>http</protocol>
<username>optional-proxyuser</username>
<password>optional-proxypass</password>
<host>proxy.host.net</host>
<port>80</port>
<nonProxyHosts>local.net|some.host.com</nonProxyHosts>
</proxy>
Update the Maven User Settings
Update Maven project
I have shifted my project to a different machine, copied all my maven libraries from old machine to new machine, did Right click on my project >> Maven >> Update Project. And then built my project. In addition to this, I have also done this one step which is shown in screenshot. And that's all it worked!!
Go to Window --> Preferences --> Maven --> User Setting, make sure you have these settings..
Also Right click on your project --> Properties --> Maven, and make sure you have the path here to maven repository..
I am facing the same issue and none of above works, like by updating the MVN also same error, by building is also same, entered details in settings.xml though even same issue.
After that again I tried and did something different which did not did before and it works.
Its simple, I clicked the force update while updating the Mvn project.
By right clicking on the pom file, there is option under Maven,
"Update Project" and it open up one popup to select update option.
PLEASE MAKE SURE FORCE UPDATE IS CHECKED, by default is unchecked. And
bingo, that works like charm!
To solve this issue I tried below method :
(I was working on eclipse IDE)
Go to location : C:\User\local.m2\setting.xml
Open setting.xml file in any editor.
Comment the proxy setting like I did(see below setting.xml file).
Then go to eclipse & perform Maven Update from :right clicking on your solution folder(Your Project)->select Maven->Update Project.
Hope it will work for you as like me.
<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
<!--
<proxies>
<proxy>
<id>optional</id>
<active>true</active>
<protocol>http</protocol>
<username>proxyuser</username>
<password>proxypass</password>
<host>proxy.host.net</host>
<port>80</port>
<nonProxyHosts>local.net|some.host.com</nonProxyHosts>
</proxy>
</proxies>
-->
</settings>
Correct me if I'm wrong, but a Mirror is used to redirect all traffic to a specific repository URL and block everything else (including Maven central repo).
Now what if I have a Mirror to http://a.com:8081 and a repository to http://b.com:8081. Would the second URL ever get used? I assume the answer is a No. Can you have multiple Mirrors?
Correct me if I'm wrong, but a Mirror is used to redirect all traffic to a specific repository URL and block everything else (including Maven central repo).
This is not entirely correct. Artifacts are downloaded by Maven by searching them inside defined repositories. Those repositories are defined in project's POM or in the Maven settings. But, as specified in the Mirror documentation:
However, you may want to use an alternative mirror for a particular repository without changing the project files.
Let's take the example from the documentation and comment on it:
<mirrors>
<mirror>
<id>UK</id>
<name>UK Central</name>
<url>http://uk.maven.org/maven2</url>
<mirrorOf>central</mirrorOf>
</mirror>
</mirrors>
This defines a single mirror that will be used when Maven will want to fetch a dependency from the Maven Central Repository. Let's say you have 2 current repositories, which are Maven Central and a custom repo A. What happens is the following:
You are declaring a dependency to an artifact;
Maven will look for that dependency inside your defined repositories, so it will look for it inside the repository A and Maven Central;
Let's say it starts with A: it will hit the URL defined for that repository, like you would expect. Then let's say it wasn't found there;
It will then look inside Maven Central. However, Maven will notice that a mirror was configured for that repository. It will not hit Maven Central at repo1.maven.org. Instead, it will fetch it from uk.maven.org, which is the URL defined in the mirror configuration element.
As this example shows, a mirror only applies to certain repositories, which are defined with the <mirrorOf> configuration element. In the previous case, we had <mirrorOf>central</mirrorOf> which means "Mirror Maven Central". This element can have various values, and the documentation gives examples:
Examples:
* = everything
external:* = everything not on the localhost and not file based.
repo,repo1 = repo or repo1
*,!repo1 = everything except repo1:
Now what if I have a Mirror to http://a.com:8081 and a repository to http://b.com:8081. Would the second URL ever get used? I assume the answer is a No.
The above shows that the answer is not strictly no. The mirror to http://a.com:8081 will be used when Maven will try to fetch a dependency from one of the repository that it mirrors. If it indeed mirrors the repository to http://b.com:8081 then no requests will ever be made to http://b.com:8081 (they will be redirected to http://a.com:8081); but if it doesn't, Maven will continue to fetch dependencies from http://b.com:8081 like usual.
Can you have multiple Mirrors?
Yes, you can.
To answer your questions:
Correct me if I'm wrong, but a Mirror is used to redirect all traffic to a specific repository URL and block everything else (including Maven central repo).
Kind of right, but I would say all artifacts are redirected to the mirror.
The blocking doesn't happen because it's a mirror. The filtering or re-direction happens based on what is defined in the <mirrorOf> element.
The syntax <mirrofOf>*</mirrorOf> causes ALL repositories to be directed to that mirror. To use your words, the mirror blocks the other repository http://b.com:8081. (but I wouldn't use those words).
If, however, you defined the mirror pattern as:
<mirrofOf>*,!third-party-repo</mirrorOf>
then the mirror would handle all artifacts that were not found in the other repositories. So in this case (in your words), the mirror would not block access to the other repositories.
Now what if I have a Mirror to http://a.com:8081 and a repository to http://b.com:8081. Would the second URL ever get used? I assume the answer is a No.
This all depends on how you've defined your mirror and repositories as explained above, it is possible for them both to be used.
Can you have multiple Mirrors?
Yes. The maven docs explain how to do that here: https://maven.apache.org/guides/mini/guide-mirror-settings.html#advanced-mirror-specification
But I've never personally had the need to deal with multiple mirrors. Instead, I typically have one mirror and then one or more repos.
I'll explain that next.
Example using a mirror and two repos
In this example, I have:
One public mirror of Maven central (called acme-central) for my fictitious company Acme.
One repo for my companies locally developed artifacts (called acme-repo).
One repo for a 3rd party company third-party-repo that has some artifacts I needed (called third-party-repo).
The simplified syntax for all of this is shown below. I'm only showing the bits of the configuration that affect this example.
<settings>
<mirrors>
<mirror>
<mirrorOf>central,!acme-repo,!third-party-repo</mirrorOf>
<profiles>
<profile>
<id>default</id>
<repositories>
<repository>
<id>acme-repo</id>
<url>https://acme.com/repository/releases</url>
<repository>
<id>third-party-repo</id>
<url>https://third-party.com/repository/releases</url>
<activeProfiles>
<activeProfile>default</activeProfile>
So we have a mirror (of maven central), and two other repositories.
The mirror statement says to use the mirror instead of maven central, but not for the two repos acme-repo and third-party-repo.
The profile is required (just because that is the syntax of the settings.xml file). You can only define <repositories> within a profile.
The repositories have names, and the way artifacts are looked up is as follows (see Repository Order in Maven docs). What follows is simplified for this answer.
settings.xml file is used
pom.xml file is used
Before downloading from a repository, mirrors configuration is applied.
The maven docs show an example with two <mirror>s.
Running the command mvn help:effective-pom -Dverbose is a good way to see which repo/mirror was used to download an artifact because the syntax is:
Downloading from third-party-repo: https://third-party.com/...
Downloading from acme-repo: https://third-party.com/...
I have a Maven project shared with a team of people. While attempting to buildi it on Jenkins, I'm looking at the details of the project's parent pom. I'd like a confirmation of my interpretation of the following setting in parent pom:
<repository>
<id>m2-local</id>
<url>file:m2</url>
</repository>
To me, the above appears to refer to the parent's m2 folder of the project. But the id m2-local makes no sense to me. There are no other references of m2-local anywhere else in the pom. I also looked for m2-local in .m2/settings.xml, but nothing for it there either. Is it possible that m2-local has no significance at all here? Also, file:m2 is for Windows notation, but Jenkins is sitting on Linux. What should it look like on Linux?
<repository>
<id>m2-local</id>
<url>file:m2</url>
</repository>
This configuration is declaring a Maven repository, whose id is m2-local and that points to file:m2. The id is just an identifier and has no other meaning. What is more relevant is the URL.
It means that when Maven will try to look for dependencies, it will look for them at the URL file:m2, along with the URL of the other potential repositories. The URL file:m2 points to a folder on the local machine called m2 and located at the same place as the POM (this is because it is using a relative path). Such a notation is both valid in Windows and Linux.
Basically, it means that for your build to run on your Jenkins machine, you need to have a folder name m2 located at the root of the project (location of the POM) and Maven will look inside for artifacts.
I suggest you read Introduction to Repositories on the Maven documentation.
I am in the process of learning maven and setting up a build environment. One thing I can't figure out, how to set up a project such that it finds a company-wide parent pom. I would like this to work:
$ git clone some_project
$ cd some_project
$ mvn install some_project
The some_project/pom.xml should reference a company-wide pom which it could get from a company maven repository. But where do I specify the company repository?
Putting it in some_project/pom.xml would probably do but then the location is hardcoded in many projects, which could lead to quite some trouble down the road should the server location change.
Having it in settings.xml could work I guess but would break the above requirement.
Edit
Thanks for the answers. I am going with the settings.xml solution although it won't allow the above sequence of commands. Seems like there is no solution that does not require some sort of initial manual setup and of the proposed solutions settings.xml is the simplest to me. Therefore I can't decide which of the two answers to accept. Both are equally good.
Here's the part from settings.xml I came up with:
...
<profiles>
<profile>
<activation>
<property>
<name>!skip</name>
</property>
</activation>
<repositories>
<repository>
<id>internalrepo</id>
<name>Central Internal Maven Repository</name>
<url>http://server.company.example.com/mvnrepo</url>
</repository>
</repositories>
</profile>
</profiles>
...
I'd recommend putting it in settings.xml.
If your company runs its own maven repo, it makes sense to have this configured in settings.xml - especially as you may need to add things like access credentials, which of course should never appear in a (shared) project pom. The only downside is that each user will have to jump through one additional (one-time) hoop when first installing their maven client.
An alternative is to not actually get the root pom from the company maven repo initially, but instead install it directly into your local repo from git. If your root pom is itself a maven project (which is not uncommon) and is available in git, simply clone it and run mvn install.
Putting the company repository URL in settings.xml is considered a good practice. You can also have associated username/password needed for repository upload.
If you care about repository relocation, you must rely on a good DNS choice (repository.mycompany.com is generaly fine) and a good usage of web servers rewrite rules.