Note: I'm asking about the command line mvn tool, although I imagine similar answers would apply to the m2eclipse plugin?
It's a bit confusing what the command line mvn targets that mention Eclipse actually do and DON'T do.
Confirming what I believe I understand:
The mvn eclipse:eclipse command is just generating Eclipse dot-project files? You would them import them into Eclipse?
The -Declipse.workspace=(eclipse-workspace-path) eclipse:add-maven-repo is just updating workspace files to point a repository, but does not tell the workspace anything about your maven projects, even if you do both steps in the same command?
When I first saw the references to Eclipse in the Maven doc I thought perhaps you could generate set of Eclipse projects and add them to a template workspace from the command line, but I guess that was just wisshfull thinking.
The m2eclipse and command line mvn tool take two very different approaches to Eclipse/Maven integration. It sounds like your question is about mvn tool.
The mvn eclipse:eclipse command reads your pom file and creates Eclipse projects with correct metadata so that Eclipse will understand project types, relationships, classpath, etc. It does not actually import those projects into a workspace as creating a workspace or importing projects into a workspace requires running Eclipse. You have to re-run this command when anything in your pom changes. Once you run this command, it is simple to import the created projects into your workspace. Just start Eclipse and use File -> Import -> Existing Projects wizard. Once you've imported projects you will not have to repeat this process after re-generating metadata unless the number of projects have changes. Just start Eclipse back up, select all projects and invoke refresh from the context menu.
Related
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
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.
I have this simple question how to import whole project source into Ecplise so I can browse it easily? Specifically, I have downloaded Maven source code http://maven.apache.org/download.html and I just want to view it same as other projects in my Eclipse.
I've tried to import it with use of two possible options (as archive and as a project) without luck.
Thank you in advance!
Maven itself is a Mavenized multi-module project, Generally there are two ways to import a Mavenized project into a IDE like eclipse:
Pre-requirment:
Suppose you have installed Maven 3 and setup environment variable
properly.
if you use Eclipse, you also need add M2_REPO to you
Build Path -- Classpath Variable, check out here for how to
setup. this tells Eclipse where to find jar dependencies stored in
local maven repository.
Option 1 -- Import as Java Project:
Open a command prompt and go to the extracted source folder, run mvn eclipse:eclipse
and waiting for it finish, make sure it doesn't popup any message start with [ERROR], this
will download all required jar dependencies from internet to you
local maven repository and create .project and .classpath for Eclipse
to use when doing import.
In eclipse, go to File -- Import -- General -- Existing Project into
Workspace, select the extracted source folder as root directory. This
will import a group of projects into Eclipse as bunch of regular java
projects (i.e. project icon inside Package Explorer watermarked with a
capital J).
Option 2 -- Import as Maven Project:
Alternatively, if yo got m2e plugin installed in Eclipse, you can
directly import the extracted project folder, go to File -- Import --
Maven -- Existing Maven Projects, select the extracted source folder
as Root Directory. This will import a group of projects into Eclipse
as bunch of Maven projects (project icon inside Package Explorer
watermarked with a Capital M).
Hope this helps.
The maven repository versions are not uploaded in the exact format they are on disc (from where the the mvn deploy goal is run. I can think of 3 options assuming I understand your question correctly:
You can find the open source project if it exists and get all the
source and project from there.
On an existing project, you go the dependencies, right click on one
and select browse source. Not the same as having the show project
here you can build and run however.
You can download the sources from the maven repo and then
reconstruct the project. I'm not not sure how feasible this
actually is and I have never tried it. I would probably find other
ways before trying this.
he fellas, i need your help again.
Im trying to develop a new part for an existing software. The parts are all done using Maven. I have to work in several projects at once, which are all continously opened in Eclipse. In Eclipse i use M2E, but i tend to edit the poms directly in xml.
So, now I can build (clean install) the projects individually, works ok. But Eclipse now has problems with the online help: It shows me errors. Eclipse cant seem to see classes which are placed in the same project, but different packages. Note that it works fine when i compile it!
Also after I run the pom the dependencies dont show up as "Maven Dependencies" but as "Referenced Libraries".
This persists after I run mvn eclipse:eclipse from outside and refresh.
Thanks so much for your help!
"Do not ever do mvn eclipse:eclipse", only do mvn eclipse:clean from command line first and then import "as maven projects" using your eclipse M2E plugin.
M2E Plugin knows how to handle Maven Dependencies, whereas mvn eclipse:eclipse knows how to handle Referenced Libraries, and they are NOT compatible with each other. You can always do mvn update project in Eclipse after mvn eclipse:clean.
I had to delete the maven-project, too, after using eclipse:eclipse. It added the references as "Referenced Libraries".
Manually deleting the .project and .settings files in the project folder and importing the project again helped. I used the M2E import. Afterwards it displayed the libraries within the "Maven Dependencies". Subsequently I was able to run it on my local webserver.
I do not really know the reason for the behavior, but deleting the project and reimporting it solved it.
I agree with kisna. As an alternative to fix the project if already contains both "Referenced Libraries" and "Maven Dependencies", you can do the following:
https://docs.oracle.com/cd/E14545_01/help/oracle.eclipse.tools.weblogic.doc/html/j2eelib/operations/opRemoveLibRefFromClasspath.html
Right-click on the project and select Properties -> Java Build Path -> Libraries tab -> Find the entry in the list of libraries called Shared Library [] or/and all libraries that starts with 'M2_REPO/', and then select it/them and remove.
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).