Can I force Maven to verify downloaded jars? - maven

I'm having a lot of problems lately with Maven 3.5.0 downloading corrupted JARs.
I don't know why, it could be a problem with my workplace's network, the repos we use, or just my computer. Anyway, usually it's easy to solve them, I just need to delete the jar from .m2/repository and force a new download. But it's making me waste a lot of time, specially because sometimes I can't tell there is a problem at all until I'm already deploying the war to the server.
Is there any command prompt, or a parameter I could add to my settings file, so that Maven would check the integrity of each downloaded jar and pom, and redownload them automatically if needed?

As far as I know there were some bugs in Maven 3.5.0 that causes corrupt jars to be uploaded to your Maven repository. I would suggest you update to the latest Maven 3.5.x version and look if that fixes your problem, because I think Maven always verifies the downloaded jars.

Related

What if maven artifact not anymore available?

As we just migrated all projects to maven projects, one question came up and I couldn't find any suitable solutions yet.
What if maven shuts down forever or just one artifact is not available anymore? Or what if some versions are not available anymore, and the software cannot run with the newer ones?
Since we're not hosting a copy of the artifacts locally, should we host copies of every jar somewhere for such a scenario?
Thanks
Unlikely, but if you build your artifacts with Maven, you already have a copy of each relevant artifact - in your local repository. If you backup it from time to time, you have the necessary level of security.
Alternatively, use a company repository manager (Nexus/Artifactory) to proxy MavenCentral. It will also keep copies of the used artifacts.

broken classpath with Intellij Idea on maven dependency

i'm using Intellij IDEA 12.1.6, almost everyone in my company use Eclipse and dont notice my problem. We have a local nexus repository where we deploy artifacts, but some of them are systematically created with an invalid maven-metadata.xml (the latest snapshot timestamp and build number does not match the effective artifact name on repo) and intellij ends up telling me those libraries have broken classpath.
Is there a way to force intellij on hooking the maven jars on my local repository without worrying about those metadata additional information? Eg eclipse hook the jar in his classpath taking the version which does not include those data (in my m2 repo dir i see both 2 jars downloaded, the one with full data and the other one without them)
eg.
library-0.0.6-SNAPSHOT.jar
library-0.0.6-SNAPSHOT-20131028.111135-10.jar
Thank you for your help.
If Importing the eclipse project did not work. You should be able to Configure the library contents . The step for Configure Library Dialog should allow you to point the library to a different location.

Intellij Debugging picking up old version project files

I am debugging code in Intellij. I use maven to build the project and there are various versions of the project sitting in the local .m2 repository. Intellij keeps on picking the old version of the code from the previous snapshot of the project when I start debugging. How do I make IntelliJ debug the latest code from the local repository?
You can tell Intellij 2016 to ask you each time which source code to step through.
File->Settings->Debugger
Show alternative source switcher
Try removing .jar and .war files that contain your code from your ~/.m2/repository/
For me the issue is that I built something and it is now registered in Maven under what Maven considers a newer version, but isn't what I was currently working on. I compiled, say, version "2.1" to debug something and then went back to working on "sand-box-idea-SNAPSHOT". I keep thinking why isn't Intellij picking up my latest sand box change but it's because it's deferring to the Maven version 2.1 which Maven assumes is better than 'sand-box-SNAPSHOT'.
It may be that you have some plug-ins interfering with IntelliJ's build process. I know that the Google Protocol Buffers Plugin can cause my Intellij to be unable to detect dirty classes that need to be re-compiled.
I've met similar behavior, maybe it can help you :-)
I developed app (using maven) and during the time I change output packaging from jar to war. Maven repository than contained both versions, jar and war, because maven does not remove old jar when you change it. As project pointed to mvn repository, it still used old reference to jar but new version within war was updated.
I was really upset as maven compilation and tests worked fine but Idea used me old version. I've had rebuild idea project and it worked later fine.
I have seen this very recently after upgrading from IDEA 13 to IDEA 14. It seems like launching configurations created in IDEA 13 are no longer automatically triggering a mvn package prior to launch.
In order to fix this I manually added a mvn goal in the "Before Launch" dialog.

Maven and ibiblio

I searched a lot in apache documentation and ibiblio.org and I could not find a decent straight answer.
My questions:
When I download a jar using maven dependency (setup in pom), how can I be sure that the file does not change on the remote repository? for example, if I'm using log4j version 1.2.3, downloaded from ibiblio.org (or any other repo for that matter), how can I be sure I'm getting the exact same jar each time?
Does maven delete jars from the local repository? let's assume I'm not clearing the repository at all, will it fill up eventually? or does maven have some kind of mechanism to clear old jars?
In Maven conventions a released version like log4j 1.2.3 will never be changed. It will be left in your locale repository until you manually delete it. It can't be changed by anyone except for the admins on maven central, but i suppose they don't do such a stupid thing.
Furthermore the download by default is done from maven central (repo1.maven.org/maven2 instead of ibiblio).
One of the "tricks" in Maven is download an artifact (released) only once...that improved your build performance in contradiction to the SNAPSHOT dependencies.
You could configure your own repository, and point all your project poms at that. It's easy to configure your poms to use a different (private) repository, but I've never set one up myself. Doesn't seem too hard, other than managing it to keep all the needed artifacts available.

How to enable inside glassfish access to maven repository?

I have a following problem. We have a central maven repository hosted on our company server. Our team is working on a project. Everyone here uses that repository to get the required artifacts. If something is missing at the moment and is required for the task that the developer is currently dealing with, he installs this artifact manually to the central repository, so that his commits don't break the automated builds.
Now, each developer also has Glassfish v2 installed on his machine. That is for testing and debugging purposes. Before committing the changes, developer makes the .ear for the project with Maven help. However, after the developer deploys the ear to it's local glassfish, frequent errors arise, because the set of glassfish libraries may not contain all the latest dependencies of the central company repository.
Right now in case of the error the developer simply reads the log and looks what exactly is missing. After that he manually copies the required jar inside his local $GLASSFISH_HOME$/lib dir. But that seems a little bit frustrating. How can this be done automatically?
Right now we are trying to implement the following solution. The developer has to synchronize his local maven repository gathering all the artifacts from the central one that are required by the project. This local repository has to be placed on the java classpath, so that glassfish would also see it. Is that a correct approach? Maybe there is a way to install directly all the required artifacts from the central repository inside $GLASSFISH_HOME$/dir and this can be done automatically during deploy?
About having to install dependencies. If the developers need to install dependencies missing from public maven repositories, take into account that usually maven proxies have the ability to cache public repos. For instance, archiva has a proxying cache. If the dependencies are your own project deliverables you should consider releasing and deploying with maven to your company repo.
About latest versions. You need to specify maven what version of dependencies should use. I would prefer editing my poms manually, anyway there's a variety of ways to achieve that.
The libraries should be part of the project, I think. If not standard libraries of glassfish, they should be included, for instance, in your war file as part of your project. If not standard but not part of your project (not the regular approach) consider managing this glassfish as a project on its own (own git/svn repo, own pom, own versions, own everything).
Good luck.

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