I am new to maven and I heard the term "maven clean repo" building ? What is the meaning of this ? How it different from the normal maven building process ? Also I want to know about the maven repository and how it changes when we build the software
I'm not sure if there is an exact term called "maven clean repo building" - but it is probably referring to doing a clean build by clearing out your entire LOCAL maven repository to ensure you have only the correct dependencies for your project.
All dependencies you need get downloaded into the repository which is at ${user.home}/.m2/repository by default. You can see this grows as the build runs and dependencies get downloaded into this folder.
The link
http://maven.apache.org/plugins/maven-dependency-plugin/examples/purging-local-repository.html explains one way of purging this.
You can change the maven repo being used for the build by providing the following argument to the build command
mvn clean install -Dmaven.repo.local=/tmp/sampleRepo
If relevant artifacts are not available in the pointed maven repo, it will download them from relevant repositories (maven central or repositories which are provided in the pom.xml file).
Hint;) Using a directory in /tmp/ will be more good as /tmp/ get automatically cleared in OS restart.
Today while doing the release of our project, the release:perform command failed in between as our nexus was having intermittent issues. The release command only able to upload one pom file to nexus.
Now, the nexus issue is resolved and I am trying to do the release, it fails as the pom file already exists and its not the snapshot version and we don't have access to nexus so that I can delete that file and start over again.
Is there any way I can pass an argument so that release:perform should continue if the file is already there and ignore this but continue with uploading the rest.
I have looked for options of such type but didn't find anything.
My last resource would be to start the release again, which will bump the version number, but would like to understand if there is any other approach where in I don't need to bump the version.
I am using maven 2.2.1
Here's how I have handled this in the past. The release:perform command does a checkout of the tag from your SCM provider (e.g. SVN). This is done in the target/checkout directory of that project - whatever is there should be an exact copy of the released tag, so it will have the right version number in the pom files etc.
If you move to that directory (target/checkout in the directory where you started the release), you can simply do a mvn deploy there and it should compile and package that version, and then upload it to your Nexus instance.
If you don't have the target/checkout directory, you can check out the Tag created as part of the release:prepare phase from your SCM system to a fresh directory and run mvn deploy there.
Since the tag in your SCM has already been created, the only thing that's left is really compiling, packaging and deploying the release, which is exactly what mvn deploy should do.
If you have provided additional parameters (e.g. for activating profiles) for the build during the call to mvn release:perform, you will have to provide these as well when you run mvn deploy.
Using this approach, your version number will not have to change, it can stay the same, since you're just uploading what has already been tagged as part of mvn release:prepare.
My advice would be for you to request from the admins that the old artifact be removed. You can either re-deploy the code from the tag by checking it out and simply doing
mvn deploy
Or rolling back your release:
mvn release:rollback
And re-doing it as usual.
It is essential to remove the old artifact from the remote repository, if the sizes do not match. Release repositories do not allow the redeployment of artifacts, unless this has been explicitly switched on on the server side.
Furthermore, #nwinkler's answer is also quite good.
My situation: I have project which contains several Maven modules. I make changes to one of them. Suddenly I find out, that my project is no longer possible to be built because of the errors in other modules. To fix this I need to run SVN UPDATE and rebuilt the project.
My assumption: probably, during the build process of my module some of the artifacts are taken from central repository and have the most newest version, while others are still outdated and taken from my local repo.
A question: I don't want to rebuild my project each time someone updates ANOTHER Maven module. I want to download the already built artefacts from the central repository without rebuilding them by myself. Is it possible?
You can tell Reactor which modules to build. In your case when you only change a single module and want to speed up the build you can pass -pl (Project Location) parameter to maven. For example:
mvn -pl module-with-changes
That will build single module, while taking other dependencies from your local Maven Repository or download from Central (whatever is the latest). That said, if you already ran mvn install for whole project and other artifacts have not been updated in Central repository, then Maven will see your local artifacts as latest and will not re-download them.
Another issue you might get with -pl parameter is when other modules in your project depend on the module that you are building. If there is a problem in dependent module you will not see it by building only the dependency model. To avoid that you can pass -amd (Also Make Dependents). Like this:
mvn -pl module-with-changes -amd
That will trigger the build for module-with-changes + modules that depend on module-with-changes + their dependents.
You can get more info about Reactor parameters from here:
http://www.sonatype.com/people/2009/10/maven-tips-and-tricks-advanced-reactor-options/
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()
In one of my Maven projects, dependency resolution will succeed once, then fail for later build attempts:
[WARNING] The POM for commons-logging:commons-logging:jar:1.1.1 is missing, no dependency information available
[WARNING] The POM for commons-httpclient:commons-httpclient:jar:3.1 is missing, no dependency information available
[WARNING] The POM for javax.mail:mail:jar:1.4.4 is missing, no dependency information available
…and so on, until I delete the maven-metadata-local.xml files corresponding to the failing artifacts (e.g. ~/.m2/repository/commons-logging/commons-logging/maven-metadata-local.xml). After those files are deleted, the next mvn invocation proceeds properly; the metadata files are restored by that invocation (presumably as part of the process of checking my upstream repositories/mirrors for updated artifacts), and I am again presented with the above errors until I again delete the metadata files.
This impacts multiple projects, though it appears to be limited to a particular set of dependencies. I suppose I could go nuclear and blow away my local repo, but I'd like to understand what the problem is.
Thoughts?
Update: It looks like it's the maven-invoker-plugin (which these builds are using for general-purpose integration testing) that is producing these maven-metadata-local.xml files. I'm not using an integration-testing-only local repo as described here, simply because doing so causes the re-downloading of all transitive dependencies (unless you want to maintain an integration-specific settings.xml file!!!). I've used the invoker plugin with a variety of other projects in this way with good results -- certainly never encountering a wedged local repository in the process like this.
Update 2 OK, this is repeatable, even after starting with a completely fresh local repository. This is on OS X, Java 1.6.0_24 with Maven 3.0.3; note that Maven 2.2.1 does NOT exhibit this problem.
Here's one of the projects in question: the 1.3.0-compat branch of rummage. To reproduce:
> mvn clean test
# no error -- can run this and other builds that don't involve maven-invoker-plugin all day w/o problems
> mvn clean integration-test
# FAIL: "Could not resolve dependencies", with warnings as noted above
> mvn clean test
# FAIL: "Could not resolve dependencies", with warnings as noted above
Once the local repository is borked (by the generation of the maven-metadata-local.xml files, AFAICT), no builds will get past the dependency resolution stage.
Running mvn -X reveals lines like this for each artifact that is later apparently not found:
[DEBUG] Verifying availability of /Users/chas/.m2/repository/javax/mail/mail/1.4.4/mail-1.4.4.jar from []
Of course, /Users/chas/.m2/repository/javax/mail/mail/1.4.4/mail-1.4.4.jar et al. does exist, as does /Users/chas/.m2/repository/javax/mail/mail/1.4.4/mail-1.4.4.pom. Totally puzzled. At this point, I'm assuming this is a bug in Maven 3 (or some underlying library), now that I see that 2.2.1 is clean.
Update 3 Bug report filed with Maven project.
This issue is resolved in aether 1.12, one rev above the aether 1.11 library that ships with Maven 3.0.3. Replacing aether 1.11 with 1.12 in one's Maven install results in expected behaviour (as noted in the bug I filed). Here's hoping Maven 3.0.4 is released with aether 1.12 ASAP. :-)
you do not mention what you may have tried, so maybe you didn't try this one: adding the -U option to force update ? (tho maybe this -U option is only relevant for SNAPSHOTs ...)
I've seen similar errors caused by corrupted files in my local repository. For example, if a download failed partway through, or a file in a remote repository changed after I downloaded it. Deleting the affected directories under ~/.m2 fixed it.