javax.persistence.spi.ClassTransformer Maven / Gradle / Ivy
// $Id: ClassTransformer.java 17752 2009-10-15 01:19:21Z [email protected] $
// EJB3 Specification Copyright 2004-2009 Sun Microsystems, Inc.
package javax.persistence.spi;
import java.security.ProtectionDomain;
import java.lang.instrument.IllegalClassFormatException;
/**
* A persistence provider supplies an instance of this
* interface to the {@link PersistenceUnitInfo#addTransformer
* PersistenceUnitInfo.addTransformer}
* method. The supplied transformer instance will get
* called to transform entity class files when they are
* loaded or redefined. The transformation occurs before
* the class is defined by the JVM.
*
* @since Java Persistence 1.0
*/
public interface ClassTransformer {
/**
* Invoked when a class is being loaded or redefined.
* The implementation of this method may transform the
* supplied class file and return a new replacement class
* file.
*
* @param loader the defining loader of the class to be
* transformed, may be null if the bootstrap loader
* @param className the name of the class in the internal form
* of fully qualified class and interface names
* @param classBeingRedefined if this is a redefine, the
* class being redefined, otherwise null
* @param protectionDomain the protection domain of the
* class being defined or redefined
* @param classfileBuffer the input byte buffer in class
* file format - must not be modified
*
* @return a well-formed class file buffer (the result of
* the transform), or null if no transform is performed
*
* @throws IllegalClassFormatException if the input does
* not represent a well-formed class file
*/
byte[] transform(
ClassLoader loader,
String className,
Class classBeingRedefined,
ProtectionDomain protectionDomain,
byte[] classfileBuffer) throws IllegalClassFormatException;
}