m2eclipse: How do I configure parameters to the Maven Project Builder? - eclipse

In Eclipse Helios with m2eclipse installed, Build Automatically is on by default. I can see that this uses some sort of incremental Maven builder under the covers (for Maven projects, obviously).
How can I customize the Maven builder so that, for example, I can supply it with some -D options? Specifically, I want my automatic, incremental Maven builds to be run with -Dmaven.buildNumber.doCheck=false. I see nowhere where I can actually affect the configuration of the m2eclipse-supplied Maven builder.
I am aware that I can create a run configuration and then explicitly build my project using Run As..., but I don't want to pursue that path. I want to customize the way my project is built when I choose the Build All command from the Project menu. I also want these customizations to be in effect when an automatic build is triggered.
I don't particularly want to add settings to my ~/.m2/settings.xml file because I don't actually want my command-line Maven installation to pick up these settings outside of Eclipse.
Thanks in advance for any help here.

At the moment, you need to put the settings in a profile and then trigger that profile. The M2E gang has removed the settings that used to be useful for this purpose.
You can make a custom settings.xml in a separate location and configure THAT in the m2e prefs.

Related

How do I get my Eclipse-Maven project to automatically update its classpath when I change a dependency in my pom.xml file?

I’m using Eclipse Mars with Maven (v 3.3). When I update a dependency in my pom (change the version), my Eclipse-Maven project doesn’t pick it up, even when I right click my project, and select “Maven” -> “Update Project.” I know this because I do not see compilation errors in the Eclipse Java editor that I see when I build the project on the command line using
mvn clean install
When I remove the project from the workspace and re-import it, then things get back to normal. However this is a cumbersome process. How do I get my Maven-Eclipse project to automatically detect changes in my pom and update the project libraries appropriately?
And yes, in the “Project” menu, “Build Automatically” is checked.
When you import the project into Eclipse, use Eclipse's own built-in Maven support (aka, m2e). I recommend against using mvn eclipse:eclipse as it doesn't give the best results (as you're seeing). Maven is a build and dependency management tool, not an IDE; expecting it to manage IDE-specific stuff is silly, in my opinion (I realize the Maven team thinks differently, that Maven should be responsible for managing your IDE, but that's nonsense).
So if you have the project available on your system, delete any Eclipse-specific files (typically just .classpath, .project, and folder .settings), they were generated by mvn eclipse:eclipse and you don't want them interfering with the "proper" import process described here. Then inside Eclipse, use File > Import > Maven > Existing Maven Projects to import the project. That should result in better integration between Eclipse and maven, including automatically updating the Eclipse build path when the pom is changed.
As a quick check, after doing the import that way, you should see a group called Maven Dependencies in the Libraries tab of the project's Build Path (in Properties dialog). Like this:
If you want the Eclipse project configuration to be automatically updated every time the pom is changed, there's a (experimental) setting for that under Preferences > Maven. Be aware that doing so might not be desirable, though - as mentioned in this feature request, it's a somewhat lengthy process that touches a bunch of stuff in the Eclipse Project; doing that automatically on every pom.xml change could end up being more trouble than it's worth.
Three Mandatory checks you should do for automatic update in your classpath
Your Repository is not in-sync with your Eclipse IDE, Please check the below settings in your IDE.
Right Click your any POM.xml from your IDE and check for the Maven profile which should be auto-activated. Also offline and Force update check box shouldn't be enabled. Please refer the below image.
Always check for your user settings which should reflect your local maven settings.xml, as shown in the below figure.
After performing all these checks, refresh your Eclipse Work-space to get these changes reflected.
Eclipse should be updating your classpath. If it's not, that implies something is going wrong.
It's hard to say what the problem could be exactly without knowing more about your project's pom.xml. More information might be necessary to solve the issue, but I'll just make a stab in the dark:
Open the .project file in your project's root folder and check the ordering of builders and natures there. It might be possible that some other nature on the project is also causing maven2Nature to fail. Move maven nature up and see if that helps any.
Alternatively you might be thinking that Eclipse does not update your dependencies because it does not add some some error indicators in the project that should be there with new dependencies. If that's the case try cleaning the current project (project>clean...). Maven in Eclipse does not necessarily trigger a full rebuild when dependencies are updated.
If none of this works, closing/opening the project might solve the issue quicker than re-importing.
What you wrote, should work. Did you check this:
does "pure" mvn install from terminal see your changes in POM?
maybe some Maybe plugin is buggy, cached some dependencies in target, and mvn clean install is needed
you can run Eclipse in a new workspace, and import your project there, sometimes it helps in case of such strange problems
instead of importing Maven project to Eclipse via m2eclipse, you can try to create Eclipse files via the old mvn eclipse:eclipse and see what happens then
does it work well when you try to import your Maven project to other IDE, the free IntelliJ Community Edition for example?
As a last resort, you can delete your current Eclipse installation and install a new version. When you add several plugins, they might interfere with one another and create weird behavior. After you do that, do not import your Maven project into your workspace, but rather create a new one and copy and paste the files that you had.

Can I Configure m2eclipse through pom.xml?

With the maven-eclipse-plugin, using mvn eclipse:eclipse, you can specifiy eclipse project natures and builders that will automatically be added to the eclipse project.
Earlier versions of m2eclipse used the configuration block of the maven-eclipse-plugin and also let you activate natures and builders using the same mechanisms. This seems to no longer be the case because a) I can't find any reference to maven-eclipse-plugin in the m2eclipse sources and b) it just doesn't work :-)
So this is my question: is there any way to configure the eclipse project generated by m2eclipse from the pom.xml? Specifically: project builders and natures, but I'd be interested in other options as well.
The following thread summarizes almost everything. First, it explains that m2eclipse doesn't and won't support anything from the Maven Eclipse Plugin anymore because:
Sonatype doesn't maintain it.
It causes them too much troubles.
Second, it states that the m2eclipse way to handle additional project natures and builders is to write project configurators:
(...) we encourage writing configurators to add the natures and builders you want based on what it available in the POM.
See this link for a guide and this project for some existing configurators for checkstyle, findbugs, pmd.
I have now implemented this as a maven plugin I call maven-eclipseconf-plugin.
Unfortunately it's proprietary work for a client, so I can't share it. But let me describe what I do:
Tied to the lifecycle verify, I check for the existence of an eclipse .project file. If it's there, I check it for the presence of the builders and natures I want to automatically add (and you can deactivate this behavior by using a maven property or a stop file with a configurable name). You can also define configuration files that will be written (like .pmd, which is related to this other question of mine). The contents of the Configuration files can be specified inline, it can come from an external file, or from a URL. I also tried to introduce variable substitution in the config files where a special placeholder would be replaced with a multi-moduke-project's root folder, but I had to give up on that approach.
Anyway, the plugin gives me pretty much all the functionality of the maven-eclipse-plugin I ever used (of course there is a lot more though) and I'm happy with that. Perhaps I will build something similar once more in open source when this contract is finished.
Project configurators are the proposed approach. But the latest version of m2e-extensions is from early 2010 and developed against m2eclipse 0.10.x. There is a successor project called m2e-code-quality which is more recent and active and developed against m2eclipse 0.12.x.
But neither m2e-extensions nor m2e-code-quality do support FindBugs at the moment. And there are some other limitations with header files, exclusions and modified JARs.
I have successfully used a universal approach with AntRun, Ant and XMLTask to automatically add project natures, builders and configuration files for Eclipse plugins from pom.xml.

How can I configure additional eclipse settings with m2eclipse?

With the maven eclipse plugin, I can configure checkstyle or sonar configurations by adding the necessary invocations to the pom.xml and calling "mvn eclipse:eclipse" to create the project configuration.
Some members of my team want to just use "Import Maven project" and therefore don't get the benefits of the project preconfigurations. Is there a way to provide the same (or similiar) hints to m2eclipse?
What I want to accomplish is that people simply "Import Maven Project", and they automatically get a project preconfigured with the correct checkstyle configuration (which is possibly downloaded from somewhere as defined in the POM) without having to manually go into the project preferences and click around a lot. That somehow defeats the purpose of automatic project generation :-)
There are more detailed answers to this topic in Can I Configure m2eclipse through pom.xml?: Completely automatic configuration can only be achieved with a ProjectConfigurator. But there is a solution based on AntRun and XMLTask even for FindBugs and Sonar. It needs manual triggering only once after checkout.
This is doable by writing custom ProjectConfigurator (as mentioned in this thread). And it looks like somebody plublished some of them (for Checkstyle, PMD, FindBugs) in the m2e-extensions project.

How do I disable maven build when using Maven 2.0 integration for eclipse?

How do I stop the "Maven 2.0 integration" plugin from running maven build, while keeping "build automatically" checked?
I'm pretty sure it used to be some check box to disable maven build before, but after upgrading Ubuntu; eclipse seems to have been updated in the process, and now I cannot find any way to turn off the maven build. The maven build takes literally minutes (about 5 minutes or so), while just running java build used to finish in seconds.
Is it no longer possible to disable it or have they just hidden it well?
If it's not possible, will eclipse be able to compile my maven project without the plugin?
(Trying to google for a solution the closes I got to an answer was several archives of this old post where the answer essentially were "You should be able to disable Maven builder in project preferences..." which doesn't really help because I cannot find any on/off settings there)
To disable the Maven Project Builder, right-click on your project then Preferences > Builders and uncheck the Maven Project Builder (you cannot modify the default maven builder).
alt text http://www.imagebanana.com/img/fikqaidv/screenshot_010.png
If this removes "too much" things, you can maybe create your own custom Maven builder. Click New, select Maven Build and configure it as you want.
alt text http://www.imagebanana.com/img/rwkmm7jb/screenshot_010.png
Disabling it seems to stop eclipse from knowing about the related projects causing the java build to fail. Is there a some sort of dummy, no-operation goal I can use for auto build goals?
I guess you would have to add the related projects in the Project References (or to uncheck Resolve dependencies from Workspace projects).
Is there a way to disable it for all 6 related projects in the workspace simultaneously?
I don't think so.
At the end, all this tweaks looks like ugly hacks. If you're not satisfied by the m2eclipse plugin, maybe you should use the maven-eclipse-plugin instead (i.e. run mvn eclipse:eclipse) instead to generate the .project and .classpath files and import your projects as Existing Project into Eclipse.

How can I reference ANT HOME from the libraries in the properties of a project when using eclipse?

In our code base we have a dependency on the ant version used in eclipse.
In the the ant.jar has been set up as a library which the project uses
This is a pain when moving versions of eclipse as the Ant plugin folder name changes (although I see it is now just called Ant1.7)
Is there a way to access eclipses reference to ANT Home which appears in the workspace preferences so that I don't have to explicitly set a variable that has the hard coded path to the ant plugins folder
Your project should not have a dependency on eclipse's version of Ant in the first place, you should keep your own version so as to decouple your project from eclipse. What if a developer or yourself decides to use intelliJ?
Although i don't know what the nature of your project is, i would have thought all dependencies should be added to your projects lib directory or something similar.
One possible suggestion would be to :
transform your project into a plugin project (properties on your project / PDE tools / convert Project to Plug-in Projects...) and
add to its dependencies the 'ant' required plugin.
That would be easier to manage when you change the version of eclipse.
Have you considered installing Ant separately, creating an environment variable, and then referencing the location via the ANT_HOME environment variable within your Ant build.xml?
From within your eclipse, on the package explorer view, right click on the specific project and build path.
Move into the Libraries tab and select the "Add Variable..." button. From here you'll see that is where the JDK system libraries path, maven(if you're using it, tomcat, eetc...) If ANT_HOME doesn't appear, you can add it by clicking the Configure Variables... button. From this moment, the ANT_HOME path will be considered in the build path of the project.
Hope it helps.
Carlos
Your ant home is available in the property ${ant.home}
E.g:
<echo> ${ant.home} </echo>
Gives the following on my machine:
[echo] D:\java\eclipse_3.4_jee\plugins\org.apache.ant_1.7.0.v200803061910