setting up a maven project in Juno Eclipse - eclipse

I recently upgraded my Eclipse to Juno and am struggling with the way maven dependencies are handled.
I installed the m2e plugin. Still, many of my projects started complaining about libraries missing as if the dependencies specified in the pom were completely ignored. This happened despite right-clicking on the project, selecting Configure --> Convert to Maven project, which seems to be the replacement for what used to be "Maven --> Enable dependencies" before. When I looked at the Maven dependencies under the project directory, there were many fewer dependencies listed than in my pom.
Running a maven compile on the command line outside of Eclipse allowed my project to build and after selecting Maven --> Update project, I was able to see the dependencies added or removed accordingly to what I specified in the pom.xml.
Bottom line: maven dependencies seem to work now but I had to do some combination of operations I didn't think should have been needed:
- Configure -> Convert to Maven project
- Maven -> Update dependencies
- Run maven outside of Eclipse
To get everything to work when with previous versions of Eclipse, all I had to do was Maven -> enable dependencies. What is the equivalent of this in Juno, i.e. what is the correct way of setting up juno Eclipse to handle properly a maven project?

I have been using Juno for a while now and the reliable way to solve Maven dependencies from within Eclipse after importing a project that is maven based is simply:
Configure --> Convert to Maven project
Maven --> Update project
Running Maven outside of Eclipse doesn't seem to help.
I am not sure why these two steps are now required when they were not before with previous version of Eclipse (at least, two steps were not needed before for sure).
Running
mvn -Declipse.workspace=<path-to-eclipse-workspace> eclipse:add-maven-repo
outside of Eclipse has brought me the problems I described in my comment to the other answer.

On a Mac running Windows under Parallels Desktop on OS X? This similar discussion may solve your problem: intellij - java: Cannot find JDK '1.7' for module

Related

Regarding Maven

I am new to Maven and if you feel i am asking really basic question then please forgive me.
I am facing couple of problems with Maven mentioned below.
I am using Eclipse Luna 4.4.1 (Which comes with the Maven Plugin).Now i installed two plugins..out of which one is for subclipse(with SVNKit) and m2e-Subclipse which is used for integrating the maven with SVN.I downloaded the project in eclipse using svn plugin as "checkout as Maven project" and i could see the project being downloaded and now to remove all the errors related with the POM.XML i downloaded the Maven and given the local path of the Maven in the preferences > Maven > installations and changed the Global Settings and user settings files which are project specific.
1). Now even after doing all this circus i still can not see the Maven build options in my Eclipse.
2). I am not even able to clean the project from command prompt.
when i go to my project directory and type "mvn -version" which shows me the correct version of maven.
But when i try to clean it using mvn clean. it does not work.
Please help.
Regards.

How eclipse maven and ant work together?

I made simple maven project and I opened it with Eclipse. I have installed maven plugin for Eclipse. I'm interested in following:
How Eclipse compiles code when I hit save on my source code (does it use configuration from ant or maven or something else)?
When I run tests from JUnit plugin for Eclipse those Eclipse calls mvn test (I suppose not, but what is then happening exactly)?
Is it possible that maven does the build successfully but Eclipse is
showing errors in code?
The Maven Integration for Eclipse makes it easier to edit POM files, allows you to execute maven builds from within Eclipse and to help with dependency management. It doesn't actually compile your code (unless of course you execute a maven build from within Eclipse). The main help is with the dependency management and writing the .classpath file of your project within Eclipse.
To try and answer your questions:
Eclipse uses its standard mechanism to compile code. With a standard eclipse for java developers your project will have a Java Project nature and Eclipse will then use the Java Development Tools - JDT to compile the code. (Internally this uses an incremental builder to build the code http://help.eclipse.org/juno/index.jsp?topic=%2Forg.eclipse.platform.doc.isv%2Fguide%2FresAdv_builders.htm). What source files it will compile and where it will place the resultant .class files is configured in your project's Java Build Path (which I am guessing the maven plugin may well configure for you)
JUnit support is part of the Java Development Tools as well.
It is possible that maven will successfully build a project outside of Eclipse, but that the same project will show errors within Eclipse. This is usually down to classpath errors (dependencies defined in the project's POM not being added to the classpath in Eclipse). If you are using the maven plugin with eclipse this probably shouldn't happen. If you are not using the maven plugin within eclipse you can execute maven eclipse:eclipse to have maven update the Eclipse .classpath file of the project which should then fix any of these problems.

Eclipse:Run on server option not visible for maven project

I'm running through the jboss as7 getting started guide here http://hudson.jboss.org/jenkins/job/JBoss-AS7-Docs/lastSuccessfulBuild/artifact/guides/developer-getting-started-guide/target/docbook/publish/en-US/html/helloworld.html . The tutorial has us setting up an example helloworld quickstart maven project.
I'm able to deploy this project from the command line successfully
mvn package jboss-as:deploy
but when I attempt to deploy the helloworld example from Eclipse - the 'run on server' option is missing from the run menu. I have Eclipse 3.7 and maven wtp installed.
Not sure how to fix, any advice appreciated.
The run on server related options only appears if your project has the Dynamic Web Moudle project facets.
You can try to configure it using the Project Facets options in your project properties
To help any other developer with this problem.
I was dealing with this issue recently. Maven projects are structured differently than Dynamic Web Projects. So when you manually add the Dynamic Web Module using Project Facets, eclipse may not register it properly as a Maven project.
To solve this, you have to install the m2e plugin and M2E Eclipse WTP plugin (this tells Eclipse how to run your maven projects).
Go to Help -> Eclipse Marketplace to search for the plugins.
After installing, you will need to restart Eclipse then you will be able to use "run on server" for your Maven projects.
Note: You may need to remove/delete the previous project then import/create it again after the restart.
You have to add maven eclipse pluginin your pom.xml file..
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-eclipse-plugin</artifactId>
<version>2.9</version>
</plugin>
According to Red Hat's site, The M2E Eclipse WTP plugin (m2eclipse-wtp) has been deprecated in favor of the newer m2e-wtp plugin. If you don't want to go through the marketplace, the URL for the new plugin is http://download.eclipse.org/technology/m2e/releases.
After copying the project and refreshing it, closing and reopening it, removing and re-adding it (right-click on server) and updating Maven... the option reappeared.
I think it occurs when you up the version of the Java compiler in your .pom file, when you up the compiler in project properties or it has to do with using the newer Jersey (2) version or when you both include local libraries and maven dependencies, it may also be a consequence of a combination of these. It's pretty unclear.
Note though, that you can still add/remove projects by right-clicking on the server in the servers tab.

How can I add a classpath entry as a publish/export dependency in an Eclipse dynamic web project?

I successfully created a project using Wicket quickstart and turned it into an Eclipse dynamic web project by running
mvn eclipse:clean eclipse:eclipse -Dwtpversion=2.0
I imported the project to Eclipse without any issues, but got this warning for each JAR:
Classpath entry M2_REPO/**.jar will not be exported or published.
Runtime ClassNotFoundExceptions may result.
I can fix this by using right click → QuickFix on each warning and selecting "Mark the associated raw classpath entry as a publish/export dependency," but this takes a lot of time and would not be possible if there were a lot of dependencies.
There must be a way to have Maven do this for me; what is it?
EDIT: I've found out that using m2eclipse core + Maven Integration for WTP (from m2eclipse extras) resolves my issues.
I'm still interested in how to achieve this without m2eclipse, though, just out of curiosity :p
The two Maven plugins needed to work with web projects in Eclipse are available from the Eclipse Marketplace.
Maven Integration for Eclipse (included in the Java version of Eclipse)
Maven Integration for Eclipse WTP

m2eclipse and Eclipse WTP

I have a very large workspace with about 30 projects all together. I am using Eclipse 3.5 with m2eclipse. I check out of my subversion repository using the defaults in order to import the projects into my workspace.
I create a Tomcat server instance, and publish my web project to the tomcat server. Sounds easy enough.
The problem is that it does not appear as though the transitive dependencies for my other projects are being automatically added to the container, so when the container starts up I get classnotfound exceptions, etc.
I go into the web project's properties, and I notice that the Java EE Module Dependencies are NOT checked for some of the transitive dependencies. I check them, and everything seemingly works until I do a project clean build, when the Java EE Module Dependencies are automatically reset by eclipse, so I need to recheck them. This is maddening, and I was hoping there was some way to automatically pull in all of the transitive dependencies when working with Eclipse WTP.
I should mention, using standard maven build works just fine, and everything gets pulled in appropriately into the resulting WAR file. It just doesn't work so good with WTP for some reason.
You need to make sure that you have "Maven integration for WTP" feature from m2eclipse installed. There is a simple tutorial available at http://docs.sonatype.org/display/M2ECLIPSE/WTP+mini+howto
What version of WTP and m2eclipse you are using? Check that dependency version declared in project's pom.xml matches with version declared in workspace project and make sure that workspace dependency resolution is enabled.
Also, you can try to run "Maven / Update project configuration" from the project popup menu and check that there is no errors on Maven console and in Eclipse's own log.
If the above won't help, try to reproduce issue on a smaller project and then submit it with a bug report
It appears as though the latest version of m2eclipse (.99x) solves all of my issues.
If you are tempted to use m2eclipse wtp extras you need to be aware that they are not supported by Sonatype and, although mostly OK, are not 100% robust.
See http://maven.40175.n5.nabble.com/What-is-the-recommended-alternative-to-m2eclipse-extras-WTP-integration-td135727.html