A tool that can hot swap the class byte code while jvm is running. Very suitable for SpringBoot framework.
Based on the jvm instrumentation tech, ASM, javassist and JVMTI.
Download swapper.jar from the release page.
Make sure you have a JDK >= 1.8.
$ java -jar swapper.jar
// All of the java processes will be listed
// Choose the pid you want to attach
// Then the backend service will startIf you want to change the HTTP server port or WebSocket port:
$ java -jar -Dw_http_port=9999 -Dw_ws_port=19999 swapper.jarAfter swapper.jar starts, visit http://localhost:8000 and use the Web UI.
Now you can enjoy the functionalities of swapper tool.
For example, Watch some methods. Trigger this method, and then the params and return value and execution time cost will be printed.
It's Watch one of the functions provided by swapper tool.
Get more functions and details from the wiki.
You can use the TUI client in the same way as the Web UI.
Install it from npm:
$ npm i -g jbs-client
$ jbs-clientOr download the standalone binary for your platform from the jbs-client-opentui releases, then run:
$ jbs-clientThe interaction flow is consistent with the Web UI.



