Import Maven dependencies in IntelliJ IDEA

Fix before IntelliJ 14

File [menu] -> Settings -> maven -> importing and uncheck "use maven3 to import project"

ref: http://youtrack.jetbrains.com/issue/IDEA-98425 (which may have a few other ideas too)

Fix IntelliJ 15+

Ran into this again, with IntelliJ 15 this time, which has no "use maven3 to import" option available anymore. The cause was that sometimes IntelliJ "doesn't parse maven dependencies right" and if it can't parse one of them right, it gives up on all of them, apparently. You can tell if this is the case by opening the maven projects tool window (View menu -> Tool Windows -> Maven Projects). Then expand one of your maven projects and its dependencies. If the dependencies are all underlined in red, "Houston, we have a problem".

You can actually see the real failure by mousing over the project name itself.

In my instance it said "Problems: No versions available for XXX" or "Failed to read descriptor for artifact org.xy.z" ref: https://youtrack.jetbrains.com/issue/IDEA-128846 and https://youtrack.jetbrains.com/issue/IDEA-152555

It seems in this case I was dealing with a jar that didn't have an associated pom file (in our maven nexus repo, and also my local repository). If this is also your problem, "urrent work around: if you do not actually need to use classes from that jar in your own code (for instance a transitive maven dependency only), you can actually get away with commenting it out from the pom (temporarily), maven project reload, and then uncomment it. Somehow after that point IntelliJ "remembers" its old working dependencies. Adding a maven transitive exclude temporarily might also do it, if you're running into it from transitive chain of dependencies."

Another thing that might help is to use a "newer version" of maven than the bundled 3.0.5. In order to set it up to use this as the default, close all your intellij windows, then open preferences -> build, execution and deployment -> build tools -> maven, and change the maven home directory, it should say "For default project" at the top when you adjust this, though you can adjust it for a particular project as well, as long as you "re import" after adjusting it.

Clear Caches

Deleting your intellij cache folders (windows: HOMEPATH/.{IntellijIdea,IdeaC}XXX linux ~/.IdeaIC15) and/or uninstalling and reinstalling IntelliJ itself. This can also be done by going to File [menu] -> Invalidate Caches / Restart.... Click invalidate and restart. This will reindex your whole project and solve many hard-to-trace issues with IntelliJ.

IntelliJ should download and add all your dependencies to the project's classpath automatically as long as your POM is compliant and all the dependencies are available.

When importing Maven projects into IntelliJ an information box usually comes up asking you if you want to configure Auto-Import for Maven projects. That means that if you make any changes to your POM those changes will be loaded automatically.

You can enable such feature going to File > Settings > Maven > Importing, there is a checkbox that says "Import Maven projects automatically".

If that doesn't help, then I would suggest to make a full clean-up and start again:

• Close your project window (and IntelliJ) and remove all *.iml files and all .idea folders (there should be one per module)
• Run mvn clean install from the command line
• Re-import the project into IntelliJ and pay attention when it asks you to enable auto-import

IntelliJ 2016 Update:

The Import Maven Projects automatically setting has been moved to Build, Execution, Deployment > Build Tools > Maven > Importing in your IntelliJ preferences.