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.
Related
All!
In our project team, people use either IntelliJ or Eclipse IDE depending on what they are comfortable with. Eacf of the IDEs have their own settings files. For instance, IntelliJ uses .idea and .iml and Eclipse uses .project, .settings, .classpath! While some other stack overflow thread says it's not needed to check in any of these files from either IDEs if you are using Maven, I'm unsure why that's the case. None of the threads say why using Maven does not warrant (some of) the settings, .project, .classpath be checked in?
Can someone help me understand 2 things
1) Why don't we need these files to be checked in when using Maven?
2) If we must check in (Assuming Maven is not used), how do we ensure that either IDEs work okay when checking out from source control and what to check in to ensure cross compatibility.
Thanks!
1) These files are not needed because bothe IDEs can import maven projects using the pom.xml file. So the pom.xml file is your single source of project description for both IDEs.
https://projects.eclipse.org/projects/technology.m2e
https://www.jetbrains.com/help/idea/maven-support.html#maven_import_project_start
2) You see it right, it's hard to ensure cross-compatibility if you use only the native project files of the IDEs. Among many other things that's why it's encouraged to separate the build chain (Maven, Gradle, etc.) from the IDE. Also continuous integration systems can be configured more easily if a unified build tool is used so it's kind of a best practice to use one and keep it independent from the IDE.
In case you don't want to switch to maven now, check in the Eclipse .project and .classpath files, Intellij is able to understand them.
I thought I understood Maven as I've worked on a few projects using it, but I seem to be having trouble creating my own project with it, so can someone correct me wherever I may be wrong?
Assuming I create a new Maven project (we'll say I did it through Eclipse or IntelliJ):
If I add a dependency to my POM file, assuming I add a public repository where that dependency can be found, shouldn't the IDE download the specified JAR and make it so that it is recognized when I use it in my code? Currently, my projects do not recognize any classes that should be found in JARs via my POM dependencies.
Assuming #1 does work, how can I determine via maven which transient dependencies I have? For example, I'm using classes from Pentaho Data Integration, and some of the plugins for it reference things like org.mozilla.javascript.*. Could maven automatically tell me that without me having to run the code, see it fail, and manually fix the dependency? There will be hundreds of those instances here, so manual fixing really isn't viable.
Here are my IntelliJ two cents:
1 - Adding a dependency in pom.xml of your project
Should indeed download the depended jar(s). You may need to approve "Import Changes" dialog if it pops in, or enable auto import.
2 - Seeing transitive dependencies
It can be achieved via Maven Dependencies Diagram - unfortunately only in IntelliJ Ultimate edition. You can use Maven Dependencies Plugin to see the dependencies tree in your favorite CLI.
Question 1: Adding a dependency
In Eclipse, depending on how you created the project, you should be able to add dependencies that are automatically recognized using the maven context menu.
Note that you should have created the project using the eclipse maven plugin so that it has maven nature.
To add dependencies/plugins from a remote repository, you can search in the resulting UI for a dependency if you know the artifactId or groupId. The plugin will pull up the deps whether the repo url is specified in the pom.xml or not.
After adding a dependency to the POM, the IDE will start downloading it and all transient dependencies as soon as you save the file.
If something goes wrong, you can try to "Update Project" from the context menu.
Question 2: Determining transitive dependencies
Transient dependencies are visible in the "Dependency Hierarchy" tab of the POM editor.
I usually default to the command line because it allows much more flexibility and functionality when tracking the dependency graph.
I am sorry but I have not worked with IntelliJ
I have a list of Eclipse projects that I would like to compile based on the existing project configuration.
As far as I can tell, if an ant script could read the .classpath files, it would pretty much be able to infer the project dependencies and perform a "javac" compilation in the right order. This would save time in describing the same dependencies again in the ant script or a Makefile.
The dependencies I am interested in are JAR Dependencies, JRE dependencies, and inter-project dependencies. These are -- as far as I can tell -- part of the .classpath XML file.
Any ideas on how Eclipse project dependencies could used in an ant script?
Right click on your Project -> Export
"General/Ant Buildfiles".
Choose the projects and there you go.
Otherwise...
I have some experience with ant4eclipse and it is a hassle to get it stable.
Go check Buckminster or Maven Tycho for a good solution.
I'm currently using Ivy along with Ant, Eclipse and Maven.
I just love the way Ivy works.
Currently, we have a workspace with many projects using Liferay (with Tomcat) for the front-end and Glassfish for the back-end.
We were looking for a way to manage our dependencies a lot better than how we were doing it.
So I took Ivy, replaced all of the classpaths and deployment dependencies in eclipse and was able to build my application using 1 ivy file per project using either Eclipse or Ant.
Ivy integrates like a charm in ant and builds are done either from the workspace or by command line.
I strongly suggest you look at this avenue. Additionnaly, by adding Artifactory, we have a local repository in which the ivy files look for dependencies. This helps us maintain and rule which jars are to be used by developpers. Once everything is setup, we will build our application nightly using Jenkins and these builds will be using our Artifactory repository to resolve dependencies since our build servers do not have access to the internet.
Hope this helped
If you are running the Ant script only from eclipse using the "External Tools Configurations", you can add the variable ${project_classpath} to the Classpath.
Depending on if you are in a plugin project and dependencies you might need to add the
${eclipse_home}.
In case you get an error launching Variable references empty selection: ${project_classpath}, make sure the ant xml file or at least the project is selected. This is important.
I believe the ant4eclipse project provides support for executing Ant builds based on Eclipse metadata files.
However, in my opinion that is doing things back to front. You shouldn't have your build (Ant) depending on your IDE (Eclipse) environment. But it is useful if you can derive your Eclipse environment from your Ant build.
This is an approach used successfully in a team I worked in. We had a helper Ant target which applied XLST to project build.xml files to transform these into Eclipse .classpath files. Thus the Ant build.xml files were the single configuration point for our projects.
When sharing a project with team members through version control, it is customary to include the .project in the source under version control. This makes sure that others on the team get all the dependencies and resources for the project. But the .project uses full/rooted paths to the resource, and not all members of a team will be working in the same environment. Even if all the members are on the same platform, the paths can often be in the user's home directory.
For the .classpath file, we can get around this problem by using build path variables. Each member defines the path to location of dependent libraries on their system, and the .classpath only refers to the variable.
This is a particular concern for Grails project - when we add a plugin, it updates the .project accordingly.
IMO resources themselves should not be part of the project at all. There is excellent plugin called m2eclipse which simplifies such tasks using Maven. It will immensely simplify your dependency management. All you'd have to keep in your version control system, besides your source code, is project configuration (pom.xml) - all the dependencies will be downloaded and cached automatically no matter what environment developer works in. There a lot more advantages in this approach - just read up on it :)
UPDATE: Just noticed "grails" tag on your question. if you're using Groovy - Maven can be replaced with Gradle. STS is probably the best Eclipse build to use if you're coding in Groovy. Next version of STS will have Gradle support.
General Approach
As others have mentioned, you should not keep the IDE files in VCS, you should keep an IDE-agnostic description of the project in VCS and generate the IDE-specific project files from them.
Java-Maven Example
Keep the pom.xml file(s) in VCS and generate the Eclipse files by running mvn eclipse:eclipse
Grails Example
A Grails project is described by application.properties and grails-app/conf/BuildConfig.groovy. These files are present in every Grails application. You can generate the Eclipse project descriptions from them by running:
grails integrate-with --eclipse
This command also supports other tools such as IntelliJ and Textmate
I don't think its standard practice to include the project file. I personally tell my VCS to ignore all IDE files, and just use VCS for the source. I include at the root level a README telling others how to configure the project (e.g. jars are in lib)
The resource links feature that you are referring to also has ability to use path variables. These are defined under Preferences -> General -> Workspace -> Linked Resources.
You could try keeping the project files in a shared Dropbox with an agreed upon path for each developer.
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.