Force the use of an alternate POM file in eclipse - eclipse

In my maven project I usually use the POM file named pom.xml. I have a second POM file though (call it pom_alt.xml), which I occasionally use to perform a very different build of the same project. To do so I specify the -f option in the command line
mvn clean package -fpom_alt.xml
as suggested by man mvn:
-f,--file
Force the use of an alternate POM file.
Now, when I am coding in eclipse I usually need maven to use pom.xml, but sometimes I should code or debug while the other file pom_alt.xml is used instead. Is there a way to tell the eclipse maven integration to use that file? Currently I am temporarily copy-pasting from pom_alt.xml to pom.xml since I seldom happen to need that, but you can see that's not optimal.
I am with Eclipse IDE for Java EE Developers, Mars Release 4.5.0.
UPDATE
I could build from the command line or use Run As Maven build as in
Carlos Andres' solution, but ideally I would like to define a persistent setting, like a property or preference. This because I find nice if the POM file can be fixed while I am doing things like running as Java Application and test cases, or executing on a server. Processes that require a project clean or server restart are often triggering a maven build with the default POM.

Check that M2E - Maven Integration for Eclipse is installed on Eclipse. Once that is installed go to the project and press right click
Next, put the command that you want to execute
This option allow you to save the commands, and the next time all your commands will be saved.
To execute the command recorded go to

Related

How do I automatically run a Maven configuration when I save a Java file in Eclipse?

I’m using Eclipse Mars on Mac El Capitan. I have a multi-module Maven project, where each module is loaded into Eclipse as a Maven-Eclipse project. My question is, if I change a Java file and save it, how do I then automatically launch an action in Eclipse that will run a Maven goal? My objective is to run a certain Maven configuration (mvn —file ../pom.xml clean package -DskipTests) every time I make a Java change.
Note that I do have the Project -> Build Automatically checked but I don’t think this has any tie in to Maven.
See the Save Hook Eclipse Plug in:
This plug-in listen for save action. If a save event is fired in the workspace, the plug-in search for a configuration file in each project. If found it will execute the specified java class or external program. The code is allowed to modify project files too. Useful to trigger some command on save, like code generation, resource sync, enhancement, deploy and so on.
For creating an own Save Action hook see hook to save action in eclipse plugin.

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.

Force Eclipse to clean a project automatically before every run

I'm looking for a solution that will force Eclipse to automatically clean a project before I run it (I'm talking about running a project using just Eclipse- no Maven, no Ant). For building I already have a Maven configuration, but sometimes I run the build directly from Eclipse as well and this is when I need that cleaning.
Shouldn't it be possible to have Maven and Eclipse use different class folders, e.g. /target for the Maven build and /bin for the Eclipse internal Java compiler? If so, you should be able to have 2 different launch configurations running the code from 2 different locations.
Second alternative: You can create a small Ant script to clear the target directory. That Ant script can be run from inside Eclipse, so a workaround is running the Ant launch configuration first and your Java launch configuration afterwards. To make this a one-step process, please install the launch groups feature from Eclipse CDT (you only need that small feature, not the whole CDT!), then you can create a "batch" like launch configuration from the other two launch configurations. Now everything is inside Eclipse with a single launch configuration!

Extract eclipse project .classpath dependencies into ant script

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.

NetBeans -- Is it possible to bypass the IDE-generated Ant build for an existing project?

I have a Java project with sub-projects that is currently built using NetBeans's IDE-generated Ant scripts. I am converting the entire project to a Maven build.
My Maven build works fine from the command line and loads perfectly in Eclipse. However, the only way I can get the project to load as a Maven project in NetBeans is to delete the Ant scripts, i.e. build.xml and the directory nbproject for each sub-project. It seems that as long as I have the old IDE-generated build files, NetBeans recognizes the project as a NetBeans Java project only, not as a Maven Java project, even though there is also a pom.xml file present.
Short of deleting the IDE-generated build files, is there any way to tell NetBeans to load the project as a Maven project?
I have been told that we want to keep the Ant build for a while during the transition to Maven.
Using NetBeans 6.9.1, Maven 2.2.
Any help would be appreciated.
Thanks
Well, the nb ant project metadata has precedence over occurence of pom.xml file (that's how maven projects are recognized and loaded). The whole precedence order hardwired in the IDE, you could only influence it be uninstalling the j2se ant project type for example.
So, yes. You need to get rid of the ant project metadata before you can open the project as maven project. Depending on how and when you delete the metadata, you might need to restart the IDE as well to get the new stuff loaded.
Have you seen http://wiki.netbeans.org/MavenBestPractices? It indicates that you must install the NetBeans maven plugin first. Perhaps that's why your Maven projects aren't recognized.
I must note that I'm not a NetBeans user anymore!
Here is what I ended up doing:
I wrote an Ant script (ironic, huh?) that, for every subproject of my project, renames the file nbproject/project.xml if it exists to nbproject/nb_project_disabled.xml. If nbproject/nb_project_disabled.xml exists instead, the script renames it back to nbproject/project.xml. In this way, the script toggles the opening of the project as a NetBeans Ant build or as a Maven build.
It would be nice if NetBeans, you know, had a setting to open both kinds of projects. Currently (6.9.1), there is just the "Open Project" command. In Eclipse, there is the command "Import Existing Maven Projects" vs. "Import Existing Project Into Workspace" (i.e. native Eclipse format).