Interface ClassTransformer


  • public 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:
    1.0
    • Method Detail

      • transform

        byte[] transform​(ClassLoader loader,
                         String className,
                         Class<?> classBeingRedefined,
                         ProtectionDomain protectionDomain,
                         byte[] classfileBuffer)
                  throws TransformerException
        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 loader
        className - the name of the class in the internal form of fully qualified class and interface names
        classBeingRedefined - if this is a redefine, the class being redefined, otherwise null
        protectionDomain - the protection domain of the class being defined or redefined
        classfileBuffer - 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:
        TransformerException - if the input does not represent a well-formed class file