Does maven maintain any setting cache? - maven

I comment out my local repository section im my pom.xml, but when I ran mvn eclipse: eclipse, it still try to download plugin from local repository. I also check the pom.xml it depends on and make sure to comment out them either, but this problem still occurs.
I think I might neglect some setting?

You may have a settings.xml in the default maven repository location .m2. If you are running maven inside eclipse, check your maven configuration inside Eclipse preferences, there you should find the location of the settings.xml file.

Related

Maven dependency not getting resolved in Intellij

I have Maven setup and updated settings.xml with proxy settings. While working on project it is unable to load any dependency in IntelliJ.
I verified all the config with one of my friend and its working in his machine correctly. Please help.
Ensure that you are pointing to correct settings.xml in the configuration of intellij
Go to-->File-->Settings-->Build,Execution,Deployment-->Mavan
and validate user settings file and local repository file, if its having different details update the path or replace the file.

maven + elicpse related questions

Forgive me asking following questions. I am totally lost in regards to maven+eclipse. I checked out someone's java project (maven built) from SVN to my local eclipse (kepler). When I click Windows > Preferences, I see Maven.
question 1)
Is this a maven plugin? When developers say maven in eclipse, are they referring to maven plugin? maven and maven plugin are two separate components?
question 2)
when I click on user settings, C:\Users\myName.m2\settings.xml is missing. Exact error message is "User settings file doesn't exist". Does it get created when you install maven plugin at first time?
question 3)
I found three folders may have to do with maven C:\workspace\maven_local_repo_artifactory directory, C:\maven_local_repo and C:\Users\myName.m2\respository but not sure how they get created and what is the relationship among them.
question 4)
Is it ok to remove current maven plugin from eclipse and re-install it then check out the java project from SVN? I think my maven or maven plugin settings are not correct in my local box.
1) Is this a maven plugin? When developers say maven in eclipse, are
they referring to maven plugin? maven and maven plugin are two
separate components?
Yes. This is the maven-plugin. maven-plugin uses the configurations of maven (%M2_HOME%/conf).
If you wanna work with maven, you need to install it on your machine. Then you can run maven commmands. In addition, if you want to invoke maven commands within eclipse (conveniently) - you can install the eclipse-plugin. "maven-plugin" is a plugin for eclipse, that lets you use maven within Eclipse conveniently.
2) when I click on user settings, C:\Users\myName.m2\settings.xml is
missing. Exact error message is "User settings file doesn't exist".
Does it get created when you install maven plugin at first time?
By default, the maven-plugin assumes that your settings.xml (which is the configuration file of maven) is in the path you have mentioned. However, there are cases (like in my case) where the config file is not there, but under %M2_HOME%/conf. you can update it in Eclipse, and the error will disappear.
3) I found three folders may have to do with maven
C:\workspace\maven_local_repo_artifactory directory,
C:\maven_local_repo and C:\Users\myName.m2\respository but not sure
how they get created and what is the relationship among them.
C:\Users\myName.m2\respository is the "local repository". If you learned a bit about how maven works, it holds a local repo on the local machine, and it keeps there all artifacts. It downloads them from the "repository" - if you have one in your company (Nexus, Artifactory, etc) or from Maven Central. However, this path is configurable by Maven's settings. So there might be that someone played with it and changed the path, and these other directories were created. You did not mention what resides inside these paths...
4) Is it ok to remove current maven plugin from eclipse and re-install
it then check out the java project from SVN? I think my maven or maven
plugin settings are not correct in my local box.
Sure it is OK. You may remove the plugin, and the source plus maven itself will not be deleted from your machine.
HTH.

Point maven settings file to refer from \.m3\settings.xml instead of \.m2\settings.xml

I am upgrading from maven 2 to maven 3. I have changed the maven home from M2_HOME to M3_HOME, created .m3 folder put the settings.xml inside it. Removed the .m2 folder also.
I see in the maven 3 global settings.xml, the default location of settings.xml is .m2\settings.xml. I could force maven to read the settings.xml from inside .m3 folder by supplying
mvn clean install -Dmaven.repo.local=C:/Users/tabeme/.m3/repository --settings C:\Users\tabeme\.m3\settings.xml
But I dont want to do this every time I build. Is there a way I can permanently make maven to read settings.xml from .m3 folder?
Maven 3 is a drop in replacement for maven 2.
It uses M2_HOME and .m2 folders as normal.
You should only change settings if you for some reason want to run multiple maven instances.

Maven fails to find local artifact

Occasionally maven complains that a particular dependency, which is built and packaged locally, cannot be found in the local repository while building another project that has it as a dependency. We get an error like:
Failed to execute goal on project X: Could not resolve dependencies for project X: Failure to find Y in [archiva repository] was cached in the local repository, resolution will not be reattempted until the update interval of internal has elapsed or updates are forced ->
Where X is the project being built, and Y is the supposedly missing artifact. If you look in the local repository, the artifact is there. This artifact is never installed in our archiva repository, so the problem is purely based in the local repository.
We have tried various profiles in settings.xml, and of course "mvn -U". Neither do any good, nor should they because this artifact never goes any further than the local repository.
The only two things that seem to work are to wait a very long time until maven smartens up, or to completely delete the local repository. Presumably the waiting option is related to the aforementioned update interval.
We have experienced this problem with maven 3.0.2 and 3.0.3. We are using Archiva 1.0.3 (but again this shouldn't be a factor). Any help would be greatly appreciated.
The local Maven repo tracks where artifacts originally came from using a file named "_maven.repositories" in the artifact directory. After removing it, the build worked. This answer fixed the problem for me.
As the options here didn't work for me, I'm sharing how I solved it:
My project has a parent project (with its own pom.xml) that has many children modules, one of which (A) has a dependency to another child (B). When I tried mvn package in A, it didn't work because B could not be resolved.
Executing mvn install in the parent directory did the job. After that, I could do mvn package inside of A and only then it could find B.
Even in offline mode, maven will check remote repositories if there is a _remote.repositories marker for the dependency. If you need to operate in offline mode, you may need to delete these files.
The simple shell command below deletes these marker files. This is safe to do if you only use offline mode for the machine. I would NOT do this on a machine that needs to pull files down from the web.
I have used this strategy on a build server that is disconnected from the web. We have to transfer the repository to it, delete the marker files and then run in offline mode.
On Linux / Unix you can delete the remote repository marker files this way:
cd ~/.m2
find . -name "_remote.repositories" -type f -delete
Maven remembers when it didn't find something. The key is "resolution will not be reattempted until the update interval of internal has elapsed or updates are forced ->"
The quick solution is to delete your local "repository" subdirectory for the problem artifact - assuming you have fixed the problem with it. :)
mvn -U will force update from remote repository - again, assuming you have now populated remote with said artifact.
When this happened to me, it was because I'd blindly copied my settings.xml from a template and it still had the blank <localRepository/> element. This means that there's no local repository used when resolving dependencies (though your installed artifacts do still get put in the default location). When I'd replaced that with <localRepository>${user.home}\.m2\repository</localRepository> it started working.
For *nix, that would be <localRepository>${user.home}/.m2/repository</localRepository>, I suppose.
If you have <repositories/> defined in your pom.xml apparently your local repository is ignored.
Catch all. When solutions mentioned here don't work(happend in my case), simply delete all contents from '.m2' folder/directory, and do mvn clean install.
Even I faced this issue and solved it with 2 ways:
1) In your IDE select project and clean all projects then install all the maven dependencies by right clicking on project -> go to maven and Update project dependencies select all projects at once to install the same. Once this is done run the particular project
2) Else What you can do is check in the pom.xml for the dependencies for which you are getting error and "mvn clean install" those dependent project first and the install maven dependencies of the current project in which you facing issue. By this the dependencies of the local project will be build and jars will be created.
I run to the similar problem when my new project depend on oracle jdbc jar(which I have installed in my local repository and work well for other projects). I tried -U option ,deleting .lastupdate file or the whole directory and downlaod again,but it did not work. finally,I deleted the directory and installed it locally again,it works.
One of the errors I found around Maven is when I put my settings.xml file in the wrong directory. It has to be in .m2 folder under your user home dir. Check to make sure that is in the right place (along with settings-security.xml if you are using that).
I had DependencyResolutionException in Ubuntu Linux when I've installed local artifacts via a shell script. The solution was to delete the local artifacts and install them again "manually" - calling mvn install:install-file via terminal.
This happened because I had http instead of https in this:
<repository>
<id>jcenter</id>
<name>jcenter-bintray</name>
<url>https://jcenter.bintray.com</url>
</repository>
check if if your artifact Y have packaging set to "jar". If you have defined it as "war" by error or copy paste, it will show this strange "was cached in the local repository, resolution will not be reattempted until the update interval of internal has elapsed or updates are forced". I would expect something like "artifact Y is war, jar type expected".
In my case I needed project Y to be a WAR to be deployed through Tomcat, as well as it needed to be a JAR to be able to add it as a dependency in project X.
So in project Y's pom.xml, I added this plugin to create a JAR along with the WAR:
<plugin>
<artifactId>maven-war-plugin</artifactId>
<version>3.2.2</version>
<configuration>
<attachClasses>true</attachClasses>
<classesClassifier>classes</classesClassifier>
</configuration>
</plugin>
And while adding the dependency of project Y in project X's pom.xml, I had to add a classifier:
<dependency>
<groupId>groupId.of.project.Y</groupId>
<artifactId>project.Y</artifactId>
<version>1.0-SNAPSHOT</version>
<classifier>classes</classifier>
</dependency>
Note: when you build project Y, you will see 2 packagings in the target folder: project-Y.war and project-Y-classes.jar, so that's why while importing you are specifying the classes classifier to import the JAR and not the WAR.
Here is the long Solution to the problem
(Not Quick fix but will work if no other solution)
You're going to hate me for saying this but this is the truth about open source projects like eclipse. Because Open source is modular and allows you to build and develop a project in many ways with many tools such as maven, spring boot, options for xml or groovy, different eclipse updates & Etc. The problem is that eclipse allows you to run the project with missing maven builds because the IDE is smart enough to resolve dependencies using a remote_repository where it stores and catches the jar files that is not properly built on the project.
Because of this feature, You may actually have local build issues but just like DNS servers; if the solution is not found in the local directory, Eclipse will look for a solution in it's remote cached repository. When you delete the remote_repository and let Maven rebuild it a second time, The project may end up creating more errors and not build a second time or may possibly rebuild a cache that was missing. But that is unlikely.
So the long answer to fix your solution.
This is a project architecture issue!
SOLUTION:
What you need to do is look in to all your dependant project's pom.xml file and the maven dependencies folder in your local project and try to resolve all the missing dependency jars in your maven dependency folder. If you have a referenced library, I suggest moving those jars into your local project's maven dependency folder.
You have to work your way into solving every child project and then navigate into your root project and fix every single project by using Maven -> Build -> clean install (check off "skip tests" & "resolve workspace artifacts") until every project builds with a clean success.
most likely, when you force update your entire solution to all your projects, you will get a list of errors that you have the IDE auto-resolve. The auto-resolve will refer to a easy reference to fix the issue. But to deploy, you have to manually fix the project because Eclipse, Spring & Maven will work well together but there are maybe a few things they don't agree on. So, you have to play diplomat in those situations and figure it out.
That's the sad truth.
All said, I have a list of problems in my project. I have this issue. The war file generated has empty jar folders and the build is not clean without errors unless i force it. The WAR file generate will run a 404 error on tomcat server production and my angular application will throw a Cors-Error when executing the API.
All the errors on my front end project is artificial because the root of all issues is the WAR file generated. It did not generate with dependencies, the Main project did not execute in tomcat and tomcat server cannot run the spring initializer to deploy the cors-policy on the server to allow my angular application to communicate. But all in all, development environment works fine with no issues.
So that is my long ended solution for this thread.
I had the same error from a different cause: I'd created a starter POM containing our "good practice" dependencies, and built & installed it locally to test it. I could "see" it in the repo, but a project that used it got the above error. What I'd done was set the starter POM to pom, so there was no JAR. Maven was quite correct that it wasn't in Nexus -- but I wasn't expecting it to be, so the error was, ummm, unhelpful. Changing the starter POM to normal packaging & reinstalling fixed the issue.
In my case I had to add mavenLocal() in root level gradle dependency
mavenCentral()
mavenLocal()

jenkins maven repository configuration

I am new to maven and Jenkins, I am trying to build a maven 3 project.
I have maven in c drive and I moved the repository to d drive.
But when I configure a build in Jenkins, it is creating its own repository(I think so)
Now How to configure jenkis, so that it can use my repository in D drive.
Hope I made sense.
you need to adjust the settings.xml to point out which repository to use.
<localRepository>C:\\USER_LOCAL_DIR\.m2\m2repository</localRepository>
where USER_LOCAL_DIR is your user directory (e.g. Users\your_user_name).
Further more you should make sure which settings.xml the maven is using, if you dont have any specific user settings.xml the maven will start using the settings.xml which is at maven configuration directory, which will be M2_HOME/conf/settings.xml (M2_HOME being the Maven home directory). The hierarchy for settings.xml is first the user .m2 directory and if it could not find that, it will try to find the one in M2_HOME/conf/settings.xml.
Hope this helps.
You may need to check for settings.xml file under
..\maven-xx\conf\settings.xml file
C:\Users\Username.m2\settings.xml file
You may need to remember precedence in the order mentioned. In case if you need to point to a private maven repository consider to check both the files and in case if it's not pointing to intended location then update the settings file accordingly.

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