ClassTransformer (Hibernate Javadocs)

All Superinterfaces:

ClassTransformer

All Known Implementing Classes:

EnhancingClassTransformerImpl
```
public interface ClassTransformer
extends ClassTransformer
```
A persistence provider provides an instance of this interface to the PersistenceUnitInfo.addTransformer(jakarta.persistence.spi.ClassTransformer) method. The supplied transformer instance will get called to transform entity class files when they are loaded and redefined. The transformation occurs before the class is defined by the JVM.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`void`	`discoverTypes(ClassLoader loader, String className)`
`byte[]`	`transform(@Nullable ClassLoader loader, String className, @Nullable Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer)`	Invoked when a class is being loaded or redefined to add hooks for persistence bytecode manipulation.

- Method Detail
  - transform
```
byte[] transform(@Nullable ClassLoader loader,
                 String className,
                 @Nullable Class<?> classBeingRedefined,
                 ProtectionDomain protectionDomain,
                 byte[] classfileBuffer)
          throws TransformerException
```
    Invoked when a class is being loaded or redefined to add hooks for persistence bytecode manipulation.
    
    Specified by:
    
    transform in interface ClassTransformer
    
    Parameters:
    
    loader - The defining class loader of the class being transformed. It may be null if using bootstrap loader
    
    className - The name of the class being transformed
    
    classBeingRedefined - If an already loaded class is being redefined, then pass this as a parameter
    
    protectionDomain - ProtectionDomain of the class being (re)-defined
    
    classfileBuffer - The input byte buffer in class file format
    
    Returns:
    
    A well-formed class file that can be loaded
    
    Throws:
    
    TransformerException
  - discoverTypes
```
void discoverTypes(ClassLoader loader,
                   String className)
```