Quick Byteman Tutorial

This is a quick tutorial on Byteman 2.0. You will need Eclipse and m2e to follow the steps below.

1. Download and unzip Byteman.

2. Create a new Maven Quickstart project in Eclipse.

3. Create the byteman script. This tutorial will use the filename quickbyteman.btm.

4. Set the content of the script.

RULE trace main entry 
CLASS App 
METHOD main 
AT ENTRY
IF true 
DO traceln("entering main") 
ENDRULE 

RULE trace main exit 
CLASS App 
METHOD main 
AT EXIT
IF true 
DO traceln("exiting main") 
ENDRULE

This script contains two rules, one injected on entry of App.main(), and another on exit. The code that runs calls the builtin function traceln(String) which prints to System.out().

5. Add the byteman javaagent to your Eclipse Run Configuration or in the Eclipse JRE. This tutorial will add it to the JRE.

 -javaagent:bytemanlibbyteman.jar=script:quickbyteman.btm 

6. Run App.java and you should see the “entering main” and “exiting main” in the console.

For more information about Byteman, visit the Byteman documentation and the Byteman Programmer’s Guide.