• Instrumentation API - provides the ability to add byte-code to existing compiled Java classes

What is a Java Agent

• In general, a java agent is just a specially crafted jar file
• It utilizes the Instrumentation API that the JVM provides to alter existing byte-code that is loaded in a JVM

For an agent to work, we need to define two methods:

• premain – will statically load the agent using -javaagent parameter at JVM startup
• agentmain – will dynamically load the agent into the JVM using the Java Attach API

Subpages

• Java - Java Agent (Creating Agent)
• Java - Java Agent (Loading Agent)

Resources

• https://www.baeldung.com/java-instrumentation