Experiment with java22 and Rust to monitor exceptions in a JVM

• It's a mini APM that leverages the java22 ClassFile API and java22 Foreign Function Interface.
• It's a java agent that instruments all throw opcodes in your bytecode with a call to a logger written in Rust.

Work in Progress. Proof of concept works, but needs optimization. Try this at home, not at work :)

Running:

• Update the path to the rust lib (temp fix) in ExceptionLogger for your setup
• mvn clean install
• cd rustlib; cargo build
• create a minimal class in a separate project

public class Main {
    public static void main(String[] args) throws Throwable {
        throw new Throwable();
    }
}

• run it with (adjust paths):

java22 -javaagent:$EXCEPTIONAL_PROJECT/exceptional/agent/target/exceptional-agent-1.0-SNAPSHOT.jar --enable-preview -classpath $YOUR_CLASSPATH Main