javax.persistence.spi.ClassTransformer - JPA interface
javax.persistence.spi
Interface ClassTransformer
A persistence provider supplies an instance of this interface to the 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:
- JPA 1.0
byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer)
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.
- Parameters:
-
loader
- the defining loader of the class to be transformed, may be null if the bootstrap loaderclassName
- the name of the class in the internal form of fully qualified class and interface namesclassBeingRedefined
- if this is a redefine, the class being redefined, otherwise nullprotectionDomain
- the protection domain of the class being defined or redefinedclassfileBuffer
- the input byte buffer in class file format - must not be modified
- Returns:
- 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
- Since:
- JPA 1.0