Why does IntelliJ want to accept incoming network connections?

Question

➠ What feature in IntelliJ is acting as a server to accept incoming connections?

When first running IntelliJ 2017.1.1 I get a dialog box asking permission for incomin

Answer 1

Problably it is linked to the below.

If you click on http://localhost:63342/ you should be able to access the built-in server. Which by default should listen only on the local interface.

Open port in range 6942-6992 seems to be linked to SocketLock.java

myServer = BuiltInServer.startNioOrOio(workerCount, 6942, 50, false, handler);

note: Ports 6953, 6969, 6970 are excluded from that range. See BuiltInServer.java

private static final int[] FORBIDDEN_PORTS = {6953, 6969, 6970};

Another open port is linked to a process org.jetbrains.idea.maven.server.RemoteMavenServer

jps -l | grep jetbrains
24628 org.jetbrains.idea.maven.server.RemoteMavenServer

You could find out open port with netstat

on Linux: `netstat -ltupne`
on OSX (something like): nettop -np java

and the related java processes with jps (as show above)

Answer 2

as doing so is a serious security risk.

It isn't, unless you don't trust the specific product. And if you don't trust a product, why are you using it at all?

IntelliJ needs to check its license once in a while, connect to update servers, maven repositories, plugin repositories, external application servers you may want to connect to, ditto with database servers.

Netbeans needs the same, you no doubt just forgot you gave it permission at some point, or it uses an external JVM that you gave permission at some point.