How do you refresh maven dependencies from eclipse? - java

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.

Related

Eclipse m2e plugin stopped changing classpath to add dependencies

I have used the m2e plugin in luna 4.4.1 for a while for handling dependencies and it worked fine. Normally, I create new Java projects then convert them into a Maven project.
I decided I wanted to start using the standard Maven directory layout, so for my most recent project I created it as a Maven project and then added the Eclipse Java facet so that Eclipse would treat it like a Java project.
This has broken Maven, so that it is no longer making it's dependencies available to new projects. Normally, Eclipse adds a "Maven Managed Dependencies" library to a project with Maven dependencies; new projects no longer do this and the dependencies are never added to the project classpath. Projects that had been working before still add and remove them normally.
I have narrowed the problem down to a .classpath error; for some reason m2e has stopped modifying the project classpath to make it's dependencies available. I can work around it by manually copying and pasting the entries from a working project but I would like to find a way to "re-automate" it correctly.
I have sidestepped the issue by finally buckling down to learn Gradle.

Make maven generate dependencies even with errors

This feels like a really stupid question but I haven't been able to find an answer.
I'm working on a maven project but I do most of my development in eclipse. Is there any way for me to force maven to generate all of my dependencies under target even if there are errors in the code? I set my eclipse project's build path to use the jars under target/dependencies/jars, but calling mvn clean kills them and if there are any errors in my code causing it to not compile mvn package won't create the dependencies but will instead just crash saying BUILD FAILURE. This makes the problem even worse since instead of seeing the actual errors my eclipse will just bombard me with errors everywhere since all of its dependencies just died.
Or maybe the way I'm working with it is just stupid and there's a better way.
Are you using the m2e plugins for Eclipse to process maven projects, or simply importing the projects as general ones?
If the latter, you should use the m2 plugins (simply go to the Eclipse Marketplace and search for Maven), as they interrogate your POM and set up your dependences properly. You can then concentrate on any compile errors in your code.
You should not point to the jars in the target folder for dependent JAR's since this is where the products of building your project are stored. Performing a mvn clean removes this folder.
To use Maven with Eclipse install the m2e plugin in Eclipse. This makes Eclipse understand the structure of Maven projects.
Once installed you can import your Maven project into Eclipse. I use Import... | Existing Maven Projects for this. But you can also directly import form a versioning system.
During the import Eclipse will set up the Eclipse project to use the Maven dependencies to locate the required JAR's. These are taken from the repository as configured with the used Maven installation.

How to use Maven with EAR

If i want to convert an EAR project a maven project , do i need to add the module in the deployment assembly as maven dependency or just use the convert in m2eclipse without any further configuration.
Me personally I wouldn't attempt any kind of conversion of an existing project. I would add the poms, make sure that mvn clean install works on the command prompt and then create a new mavenized Eclipse project from the poms.
The main reason is that you current project settings are effectively wrong when you switch to Maven - the Maven poms are the truth and what feeds the Eclipse project setup, so you really do not want to make your life difficult and work against m2eclipse - let it do the project creation for you. Fresh.
You can install m2eclipse and then do the following as well.
Go to the project menu (right click on Package Explorer) > Configure > Convert to Maven Project
Open the pom.xml and right-click and choose Run As -> Maven Clean. Similarly Choose Run As -> Maven Install.
Note : Please ensure that your eclipse project settings are correct and classpath libraries are not absolute and you don't have any project specific environment variables defined in your workspace. Please take a backup of your project before you do this.This is to ensure we don't mess up the current stable project configurations. Once m2eclipse generates the pom.xml for your project, you can update and make changes to it to
fully obtain a mavenized ear build. hope this helps
You can also try creating new maven project with archetype selection of "jboss-javaee6-ear" and follow the similar structure for your project. Most probably you will need parent Pom and child poms per each module (ejb, war, jar etc). There are other few similar approach but almost all of them requires you to have mulitple POMs
maven-ear-plugin and JBoss AS 7
You can also go through all the examples for maven ear plugin to find settings suitable for you
http://maven.apache.org/plugins/maven-ear-plugin/
I ended up ditching ear for war :) single POM and even ditched the JBOss for tomcat/jetty :)
If you want to convert your existing eclipse dependencies into Maven dependencies, you can try the JBoss Tools (JBT) Maven integration feature, which contains an experimental conversion wizard, plugged into m2e's conversion process : http://docs.jboss.org/tools/whatsnew/maven/maven-news-4.0.0.Beta1.html.
So, all you have to do is, as Keerthi explained, right-click on your project and Configure > Convert to Maven...
If your dependencies already are maven artifacts, it should work easily. If not, you'll need to convert them to Maven (if they're workspace projects) or make them available in your maven enterprise repository, before converting the EAR project.
JBT (requires Eclipse JavaEE) can be installed from http://download.jboss.org/jbosstools/updates/stable/kepler/ or from the Eclipse Marketplace (See https://marketplace.eclipse.org/search/site/jboss%2520tools)

How to fix m2eclipse plugin?

I have java maven project in Eclipse that depends from other projects and for near 1000 library jar.
But I cannot use m2eclipse at all.
For create Eclipse project is use eclipse maven plugin like:
mvn eclipse:eclipse -Dwtpversion=1.5
It works well. But when I go to Eclipse and click on m2eclipe - update dependencies - all library jars disappear!
So for work I have disabled java projects as maven in Eclipse. I suppose that there is some problem with eclipse internal variables. Does it correct? What have I check? Does exist some log? Or this is common bug of m2eclipse plugin?
Thanks.
maven eclipse plugin (i.e. mvn eclipse:eclipse) no longer works with m2eclipse or its current version, m2e.
Assuming you have the latest Eclipse (Indigo, which comes with m2e), you should have better success opening the maven project directly (Import as Maven project).

Eclipse: Dependency Management

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

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