How do I add a JVM argument to Spring boot when running from command line?

Question

I'm using Spring Boot 2.1.5.RELEASE. I want to start the embedded Tomcat server passing in some JVM arguments so that I can debug my application in Eclipse. I tried doing this

localhost:todoapp-backend davea$ java -jar build/libs/todoapp-backend.jar -Drun.jvmArguments="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,address=8787"

and also this

localhost:todoapp-backend davea$ java -jar build/libs/todoapp-backend.jar -Xdebug -Xrunjdwp:transport=dt_socket,server=y,address=8787

but neither seems to do anything since it appears the server starts normally, but my debug port is closed (per telnet) ...

localhost:todoapp-backend davea$ telnet localhost 8787
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
telnet: connect to address 127.0.0.1: Connection refused
telnet: Unable to connect to remote host

Answer 1

Use for enabling debugging via remote:

java -jar myapp.jar -Dagentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=8000

or via maven run goal like :

mvn spring-boot:run -Dspring-boot.run.jvmArguments="-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5005"

Change address port to any value that you want to use.

In springboot 2 onwards there is no need for the -Drun.arguments part, you can skip that and provide the environment overides arguments directly after -D like :

$ java -jar myproject.jar --spring.config.name=myproject