[java] How to add directory to classpath in an application run profile in IntelliJ IDEA?

I'm trying to add a directory to the classpath of an application run profile

If I override by using -cp x:target/classes in the VM settings, I get the following error:

java.lang.NoClassDefFoundError: com/intellij/rt/execution/application/AppMain

Any idea on how to add a directory to the classpath for my project?

Suppose you need only x:target/classes in your classpath. Then you just add this folder to your classpath and %IDEA%\lib\idea_rt.jar. Now it will work. That's it.

Simply check that the directory/package of the class is marked as "Sources Root". I believe the package should be application or execution in your case.

To do so, right click on the package, and select Mark Directory As->Sources Root.

Set "VM options" like: "-cp $Classpath$;your_classpath"

It appears that IntelliJ 11 has changed the method, and the checked answer no longer works for me. In case anyone else arrives here via a search engine, here's how I solved it in IntelliJ 11:

1. Go to the Project Structure, click on Modules, and click on your Module
2. Choose the "Dependencies" tab
3. Click the "+" button on the right-hand side and select "Jars or directories..."
4. Add the directory(ies) you want (note you can multi-select) and click OK
5. In the dialog that comes up, select "classes" and NOT "jar directory"
6. Make sure you're using that Module in your run target

Note that step 5 seems to be the key difference. If you select "jar directory" it will look exactly the same in the IDE but won't include the path at runtime. There appears to be no way to determine whether you've previously selected "classes" or "jar directory" after the fact.

You need not specify the classes folder. Intellij should be able to load it. You will get this error if "Project Compiler output" is blank.

Just make sure that below value is set: Project Settings -> Project -> Project Compiler output to your projectDir/out folder

You can try -Xbootclasspath/a:path option of java application launcher. By description it specifies "a colon-separated path of directires, JAR archives, and ZIP archives to append to the default bootstrap class path."

I am using Idea 8. in your module dependancies tab (in the project structure dialog). Add a "Module Library". There you can select a Jar Directory to add. Then make sure the run profile is using the Classpath and JDK of the correct module when it runs (this is in the run config dialog.