Book Image

Mastering Eclipse Plug-in Development

By : Alex Blewitt, Bandlem Limited
Book Image

Mastering Eclipse Plug-in Development

By: Alex Blewitt, Bandlem Limited

Overview of this book

Table of Contents (18 chapters)
Mastering Eclipse Plug-in Development
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Free Chapter
1
Plugging in to JFace and the Common Navigator Framework
Index

Overview of ClassLoaders


One of JVM's biggest contributions to runtime loading has been the ClassLoader design and infrastructure. This allows a JVM to load the bytecode from arbitrary locations or even generate them on demand. It was this infrastructure that enabled Applets and Remote Method Invocation (RMI)—two key technologies that propelled Java toward enterprise use in the late 1990s.

The purpose of a ClassLoader is to take a class name (such as com.example.Test) and return an instantiated Class object. This typically involves translating the name to some kind of file reference (such as com/example/Test.class), loading the content of that file, and passing it to the JVM to define a Class. ClassLoaders can also be used to synthesize classes on demand or even weave additional data to the classes at load time.

The most common ClassLoader used in Java is the URLClassLoader. This takes an array of URLs that either point to JARs or directory roots, and when a class is requested, it iterates...