Is there some way to stop Maven from resolving artefacts in the Eclipse workbench?
I know I can set it manually, but I would be nice if it can be set through the POM.
No I don't think so. In my opinion Maven even should not bother about IDE settings. This would only mess up the POM (like already done with the eclipse lifecycle-mapping configuration for plugins in eclipse).
I would support if this would be a global setting of the m2e plugin of eclipse.
There's a plugin that will do it: see http://code.google.com/p/mad-mvntools-m2eclipsegen/
Tested and this works fine (it's available in mvn central so no additional repos).
Related
m2e is no longer working in my Eclipse Indigo. Nothing is printed to the Maven console, I can't download any sources and some dependencies won't be resolved.
I'm using the embedded Maven installation.
Do you know how to fix this issue?
Just a wild guess (due to similar problems I had in the past):
If you use the embedded m2e Maven installation, Maven has no information to your settings.
If you are in a corporate environment, you have to set your proxy in a Maven related location:
In your users settings.xml file.
In your Maven installation settings.xml file
m2e can only use the proxy set in your Maven settings file, not the one in your eclipse environment. So as a result, you could see all the old libraries contained in local repositories, but no new ones contained only in remote repositories located somewhere on the internet.
Please add some more information about your configuration in eclipse (does eclipse find your user settings.xml file?) and the errors you get.
Try -clean workspace option. Or if it doesn't help, create new workspace, test if m2e started working and import your old projects. I just resolved issue very similar to yours using second option.
Here is good explanation of such kind of troubles: http://www.eclipsezone.com/eclipse/forums/t61566.html
I've just set up a brand new installation of Eclipse Helios and have configured M2Eclipse to use an external (v 2.2.1) installation of Maven.
The system compiles fine on the command line, but from within M2Eclipse several of my project modules have an error:
Missing artifact javax.jms:jms:jar:1.1:test
I can get past the error by excluding the jms artifact from the Atomikos dependencies. But my main question is how can the two provide different results!
Even more odd is that I have another installation of Eclipse Helios and everything works fine.
The dependency resolver in m2eclipse is not using the external Maven installation, it has to use the embedded Maven version. So, I'd recommend to get the latest version of m2eclipse, as well as Maven 3.x version to minimize the difference in dependency resolution.
Additionally, it is possible that you had some alternative repositories defined in your maven 2.2.1 conf/settings.xml file. If you use the embedded maven3 these will be ignored.
You also can specify your maven 2.2.1 installation as the maven installation for m2eclipse.
I posted a similar question and finally found an answer. See m2eclipse says "Missing artifact" but I can build from cmdline!
You can find a different solution at http://getsatisfaction.com/sonatype/topics/_missing_artifact_from_m2eclipse_but_it_is_not_true
Same problem here: I use maven 2.2.1 as the installation to use from eclipse, as it is the one which works on the command line. Maven 3 does not work for this concrete project, complaining about some missing dependencies which, after much research, in my case turned out to come from old maven 1 repositories with legacy layout. Maven 3 hates these and will burst burst into cry when it finds them.
So maven 2 works just fine on the command line, but maven 3 does not. The problem with eclipse is that even if you specify maven 2 as the installation to build your projects, it uses maven 3 (the embedded installation) for dependency resolution, so if you are so unlucky to require a legacy repository you are screwed (I mean, eclipse won't help).
I have a project (built from an AppFuse template) that requires Maven 2.2.1. So I upgraded to this (from 2.1.0) and set my path and my M2_HOME and MAVEN_HOME env variables.
Then I ran mvn eclipse:eclipseand imported the project into Eclipse (Galileo).
However, in the problems list for the project (and at the top of the pom.xml GUI editor) it says:
Unable to build project
'/export/people/clegg/data/Workspace/funcserve/pom.xml;
it requires Maven version 2.2.1
This persists whether I set Eclipse to use its Embedded Maven implementation, or the external 2.2.1 installation, in the Preferences -> Maven -> Installations dialog.
I've tried closing and reopening the project, reindexing the repository, cleaning the project, restarting the IDE, logging out and back in again, everything I can think of! But Eclipse still won't believe I have Maven 2.2.1.
I just did a plugin update so I have the latest version of Maven Integration for Eclipse -- 0.9.8.200905041414.
Does anyone know how to convince Eclipse I really do have the right version of Maven? It's like it's recorded the previous version somewhere else and won't pay any attention to my changes :-(
Eclipse allows you to specify an external Maven installation. But there's a catch. :(
Have a look at Windows > Preferences > Maven > Installations.
You will see a message like this:
Note: Embedded runtime is always used for dependency resolution, but does
not use global settings when it is used to launch Maven.
To learn more, visit the maven web page.
Translating to English, it means that Eclipse will continue to employ its internal Maven instance in order to perform some tasks.
When you "Run As > maven install" it will run your pom.xml script employing the external Maven instance you specified but when Eclipse performs some of its internal stuff, it will continue to use the embedded Maven instance, whatever version it is.
(edited)
As far as I know, when you install M2Eclipse you are implicitly defining which "internal Maven instance" you will have, which is exactly that one packaged by the plugin.
In the plugin configuration, you can add external Maven instances by telling where they are installed.
If you are using a recent m2eclipse version, you can try this too:
<prerequisites>
<maven>>=2.2.1</maven>
</prerequisites>
Notice the greater than in >=2.2.1. It works fine for me.
A common source of trouble (of this kind) is if you change global preferences and don't remember or know that you have enabled some project specific settings. At least it's a chance that the global setting is now set to use the external maven but the project setting is still set to 'embedded'.
M2Eclipse uses an embedded maven instance, not the maven instance you have installed on your system.
Have you tried switching workspaces?
You can still reference the same project in the new workspace. This would provide about as much of a reset as you can do in terms of eclipses internal settings.
Try creating your eclipse project with mvn project:m2eclipse or use the maven import option under import project.
Using m2eclipse, my fallback in these situations is to do Maven > Update Dependencies and then Maven > Update Project Configuration. The first is just me being supersticious, but the second will rewrite .project and .classpath.
As Pascal says about, m2eclipse can also be pointed at an external instance. I've done this in the past, though not at 2.2.1.
Dan
I got the same issue. Resolved it by restarting the system because every time you change the 'Path' in environment variables you should restart the system or else if would not pick the changes.
What are some methods of utilising Eclipse for Dependency Management?
I really like the The Maven Integration for Eclipse (m2eclipse, Eclipse m2e). I use it purely for the dependency management feature. It's great not having to go out and download a bunch of new jars new each time I set up a project.
A simpler way to go is the Maven Eclipse plugin (as opposed to a Maven plugin for Eclipse). It's simply a maven plugin that generates the .project and .classpath file based on the contents of the pom, you just run mvn eclipse:eclipse and you're done. It uses a classpath variable in Eclipse to locate the local maven repo.
I personally prefer this approach most of the time because you have more control over when the maven plugin updates are done. It's also one less Eclipse plugin to deal with. The GUI features of the m2eclipse plugin in the latest version is pretty nice, though.
There's also an alternative to the m2eclipse plugin called Q4E, now called Eclipse IAM.
Another option is ivy. Ivy has eclipse integration as well.
A comparison of maven and ivy can be found here:
http://ant.apache.org/ivy/m2comparison.html
We recently started using maven for dependency management. Our team uses eclipse as it's IDE. Is there an easy way to get eclipse to refresh the maven dependencies without running mvn eclipse:eclipse?
The dependencies are up to date in the local maven repository, but eclipse doesn't pick up the changes until we use the eclipse:eclipse command. This regenerates a lot of eclipse configuration files.
Have you tried using the m2eclipse plugin? I use it with eclipse and it maintains the eclipse .classpath when I add dependencies. It'll also check for updated dependencies.
You generate the special eclipse files with mvn eclipse:eclipse, but once you've done that, you should let a plugin handle the dependencies while inside eclipse.
That's how we do it at my work place, and it generally works well.