How to run NetBeans 31 through terminal as a specific instance by project?

[manueljordan]

Hello Friends

I have installed NetBeans 31 in Ubuntu and I am able to execute the IDE in peace through the terminal with the ./netbeans script file execution. I've created two projects as follows:

• File -> New Project -> Java with Maven -> Java Application

For simplicity consider the projects as:

• spring-framework
• spring-boot

Now in Eclipse is possible open the IDE for a dedicated workspace as follows:

./eclipse -data /home/user/path/to/workspace/spring-framework
./eclipse -data /home/user/path/to/workspace/spring-boot

Therefore is opened 2 instances of the IDE. Each one for a dedicated workspace. So is possible move each instance (window) to a specific monitor. Furthermore for each instance is possible edit it isolated against the other (.ie: the Views)

I know the workspace term does not exist in NetBeans and so far the best equivalence is a project.

./netbeans /home/user/NetBeansProjects/spring-framework
./netbeans /home/user/NetBeansProjects/spring-boot

But practically the second project is opened within the single unique instance. In other words together with the first project

Therefore:

Question

• How to run NetBeans 31 through terminal as a specific instance by project?

Is possible accomplish that goal?

Thanks in advance

[ChangkeunJ]

Yes, --userdir is the flag you're after. It's the closest thing NetBeans has to Eclipse's -data:

netbeans --userdir ~/.netbeans-instances/spring-framework
netbeans --userdir ~/.netbeans-instances/spring-boot

Each userdir carries its own settings, its own list of open projects and its own window layout, so you end up with two genuinely separate IDE windows you can put on different monitors and configure independently of each other.

The reason your current commands collapse into one window is that NetBeans keeps a lock file inside the userdir and uses it to notice an instance that's already running. Both of your invocations resolve to the same default userdir, so the second one finds that lock, hands the project path over to the process that's already up, and exits. Point them at different userdirs and there's no lock to find, so you get a second process.

You don't need to pass --cachedir alongside it, which is the bit people usually go hunting for. netbeans.conf spells it out: if you give a non-default --userdir and no --cachedir, the cache goes to <userdir>/var/cache on its own, so the two instances aren't quietly sharing one.

One adjustment to the mental model that might help. The userdir is the instance, not the project. Passing a project path on the command line only opens that project inside whichever instance the userdir resolves to. So the userdir is what decides which window you land in, and opening the project is a separate thing you do once and let it remember.