How to Run Java on the Command-Line to Attach a Debugger
It can be pretty useful to attach a debugging to a Java process, such as when you're running a JAR as a standalone process.
We can use the following to set up a debugger on port 5050:
# wait for the debugger to attach before running the process
java -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=y,address=5000
# don't wait for the debugger to attach before running the process
java -Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5000