无法在 IntelliJIDEA 中打开调试器端口

It happens occasionally that when I restart my computer, everything is OK. Perhaps there is a port conflict.

Restart the computer works because instances of Java or Tomcat are killed during the restart. You can also consider killing the specific processes from Task Manager

This also happens if there is an issue in the context.xml file. In my case, I had accidentally changed the context value.

the key to the issue is in debugger port. I was having the same problem, I was killing every process listening on port 8081 (my http port), 1099 (JMX port), tomcat shutdown port, every java.exe, and still nothing.

The thing is this debugger port is different. If you run the application, it will go through the port you have Tomcat configured for, 8080, 8081 or whatever. But if you run it in Debug mode, it goes through a different port.

If you go edit your Tomcat configuration from IntelliJ, the last tab is Startup/Connection. Here go see the configuration for Debug mode, and you'll see its port. Mine was 50473. I changed it to 50472, and everything started working again.

I had same issue in windows 7 and IntellijIdea 14. I killed the java processes by going CTRL+ALT+ESc, find java and kill it. Now Re-Run, the application again it should be fine.. You can also do it with command line or shell(linux), but I found this easier for myself

I have the same issue,because my computer's DNS miss 127.0.0.1 localhost. When I add 127.0.0.1 localhost to my host file,it become ok.

While debug I got this issue: It worked with

1. tried changing my Tomcat http port 8082 to 8083(In debug configurations on IntelliJ and in Tomcat->conf->server.xml also)
2. tried changing JMX port from 1099 to 1009.
3. tried changing debug port in Startup/Connection in debug configurations
4. killed all java processes in TaskManager->Processes.

This works for me consistently (it happens to me from time to time, when I do things such a restart tomcat when I am running the integration tests, for example)

1) Find the process that has the port 1099 open

sudo netstat -anp | grep tcp | grep 1099
cp6       0      0 :::1099                 :::*                    LISTEN      9857/java

2) kill it

kill 9857

3) Start Tomcat.

For me, IntelliJ Event Log (right bottom corner) had below logs:

Error running EntitmentTooling-Debug: Cannot run program "/path-to/apache-tomcat-8.5.15/bin/catalina.sh" (in directory "path-to/apache-tomcat-8.5.15/bin"): error=13, Permission denied


Error running EntitmentTooling-Debug: Unable to open debugger port (127.0.0.1:58804): java.net.SocketException "Socket closed"

The command

$ chmod a+x /path-to/apache-tomcat-8.5.15/bin/catalina.sh

to sufficiently change privileges worked for me.

There are various reasons for this.
- There might be the problem with debugger port---Please change it to resolve( answered by T.M )
- There might be some issue with intellij cache --Invalidate cache and restart will solve it ( answered by feng smith )
- There might be problem with any other Port, like JMX, AJP --- Please change these port numbers as well.
I wanted to add this as comment but not enough rep

None of above methods worked in my case i.e. changing port number in run configuration, machine restart, invalidate cache in IntelliJ, killing process shown in netstat (nestat -anob | findstr <port-number> and then tskill <pid>). The only thing that finally helped was starting and shutting down tomcat manually via startup.bat and shutdown.bat (you should use correspondig .sh files on linux and macOS).

I solved the issue by this way.

1. I tried to kill all the java.exe processes but it was useless.
2. Then I tried deleting the Tomcat server
3. I re-deployed the project and restarted the project and it worked.

See these links for more information:

Delete Tomcat

Add a new Tomcat

In my case, there was a problem in server.xml for Tomcat/conf folder where I had extra comment tags under another comment tag. So I think, since there was some problem in server.xml, it was not able to start Tomcat. And moreover it copies the tomcat folder from your installation directory to C:\Users\username.IntelliJIdea2017.2\system\tomcat\Tomcat_service

I had this exact message.

The reason was that some IDE (I use Eclipse and Intellij) failed to shutdown the tomcat server. Or maybe crashed before it could do so.

The solution was to navigate to C:\...\apache-tomcat-xxx\bin and run shutdown.

The only thing that worked for me is to go to Task Manager on Windows, and end all the Java processes that is running by right click -> end Task.

There are multiple solution for the same.

1. Either we may close the IDE (e.g. IntellJ)
2. Find t IND00123:bin devbratanand$ lsof -i:30303 COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME idea 437 devbratanand 56u IPv4 0xb2720e580a7d6483 0t0 TCP 10.17.130.41:55222->vmqp-cms-pan-app1.emea.akqa.local:30303 (ESTABLISHED) IND00123:bin devbratanand$ kill -9 437

If you're on windows you can bypass the socket issue completely by switching to shared memory debugging.

This happens when you have application running on the same port number. One way to do this by killing the process forcefully. Open command prompt as an admin. Run command 'taskkill /IM "java.exe" /F'. This worked for me in Windows. Let me know if this works.

1. Check "Run" configuration to see which port it is using (8081).
2. Find all the other processes using that port lsof -t -i :8081
3. Kill the processes on that port. kill PROCESS_ID
4. Run Tomcat in Debug mode.

In my case, I wasted so much time on changing debugger port but it was not the issue. Since tomcat was not able to run on the port I chose in Run configuration, I was not able to debug my service.

In Server tab of Tomcat configuration in IntelliJ, change JMX port to another number.

Change debug port of your server configured in the Intelli J.

It will be fixed.

All the other solutions unfortunately did not work. This is what worked for me . I simply changed the debugger port to some other port number.

Intelij-> preferences->Build, execution, deployment ->Debugger-> Built in server->port(change value )

In my case I had another project open in IntelliJ, and had Tomcat running in debug mode in that project. Stopping that instance of Tomcat resolved the issue.

My assumption that this exception usually occurs when Tomcat is improperly closed and still holding the ports. Usually it is enough to kill any process listening to 1099 port. For Window 10:

netstat -aon | find "1099"




taskkill /F /PID $processId

Probably you get the same error message if the standalone.xml in your standalone/configuration folder cannot be found. At least I have the same error when using a WildFly 14.0.1:

I have encountered the same error while using IntelliJ. Since I have started multiple instances of IntelliJ. While starting two instance it started properly. However, when starting another one, it was giving below error.

unable to open debugger port (127.0.0.1:debug-port-number) java.net.socketexception interrupted function call accept failed

There are basically two places you can check your ports related to debugging in IntelliJ

1. JMX port - you can find this is
2. In Startup/Configuration, there is debug option just click this.

What to Check: If IntelliJ is throwing above error, means issue is any of the above listed ports. To verify this open event log (its available in right corner down) and check the exact message. Event log will have message like below

11:19 PM    Error running 'Tomcat-tp': Address localhost:1098 is already in use


11:19 PM    Error running 'Tomcat-tp': Unable to open debugger port (127.0.0.1:51787): java.net.SocketException "Interrupted function call: accept failed"

Solution-1 Check the JMX port of current intelliJ which is not starting with the working one and verify if JMX ports are not duplicated within IntelliJ instance or any of the software which is running in your machine is not using this port.

Solution-2 If JMX is not duplicated then verify your debug port, check in all IntelliJ instance and do the changes.

Surely either JMX or Debug port is having issue just use unique JMX and Debug port and it will work.

Hope this will help someone.

Just restart the Android studio before try these all. I face same right now and i fix it by this way.

Happy coding :)

For anyone who comes here with the similar message:

Unable to open debugger port (127.0.0.1:50470):
java.net.SocketException "Interrupted function call: accept failed"

This may be caused by something completely independent, i.e. it's not a port configuration. If you're running Tomcat, for instance, it may be that you have an invalid web.xml. Check your Event Log for any previous errors:

Cannot load C:\...\conf\web.xml: ParseError at [row,col]:[480,29]
Message: The element type "param-value" must be terminated by the matching end-tag "</param-value>".

Running IntelliJ as Administrator in Windows did the magic for me:

I came in this scenario and as the above answers I tried to change the port like Edit Configuration -> Startup/Connection -> debug -> change the Port but it didn't solve my problem cause I was running my application in debug mode so once try to run the application as normal without debug. it solved my problem!

My fix was the change debug port from 54444 to 7070

This problem is sometimes just because of a misconfiguration.

Please, check if you have, for example, an SSL port number defined at your run configuration. If so, and if you don't have a right configuration for it at tomcat's server.xml, then it won't be possible to start your debug session correctly, and you will unfortunately have the same error. I think this can be shown as a different error. So, this is in my opinion an idea issue also..

The solution is, removing the SSL port number value from the run configuration of the IDE.

#intellij-idea https://stackoverflow.com/questions/tagged/intellij-idea

This occurred to me, when I was running wildfly on intellij, and I switched the branch. I stopped wildfly, built the jar using maven, tried to re run Wildfly and got the error.

I tried changing port as mentioned in the accepted answer, but didn't work. I tried to find the process running on port, but netstat command didn't find it.

I tried restarting the OS, it also didn't help.

Then I checked the configuration folder of my Wildfly set up, that's when I realised

standalone.xml got replaced by standalone.xml.tmp

renaming it to standalone.xml helped me to resolve the error.