спецификации, руководства, описания, API

Java™ java.lang.instrument Package

The java.lang.instrument package provides a Java™ programming language API for tools to instrument Java programming language applications -- for example, to monitor them or collect performance information. Tools use java.lang.instrument to modify the class file that defines a class -- generally, by inserting into the byte-code of methods additional byte-code which will perform the instrumentation.

java.lang.instrument was introduced in JDK™ 5.0.

API Specification

java.lang.instrument Package (package description)

API Enhancements

See the API Enhancements in JDK 6 - An annotated list of API changes between the 5.0 and 6 releases.

More Information

Java Virtual Machines Tool Interface - a native interface which can also perform instrumentation.
java.lang.management package - the monitoring and management package, often useful with instrumentation.