ClassTransformer (Java EE 5)

Java EE API

previous page next page

Overview

Package

Class

Tree

Deprecated

Index

Help

PREV CLASS NEXT CLASS

FRAMES NO FRAMES

SUMMARY: NESTED | FIELD | CONSTR | METHOD

DETAIL: FIELD | CONSTR | METHOD

javax.persistence.spi Interface ClassTransformer

public interface ClassTransformer

持久性提供者向 PersistenceUnitInfo.addTransformer 方法供应此接口的实例。在加载或重定义实体类文件时，将调用供应的转换器实例来转换该实体类文件。转换在 JVM 定义类之前发生。

since

Java Persistence 1.0

英文文档：

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:: Java Persistence 1.0

Method Summary
`byte[]`	`transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer)` Invoked when a class is being loaded or redefined.

Method Detail

英文文档：

transform

byte[] transform(ClassLoader loader,
                 String className,
                 Class<?> classBeingRedefined,
                 ProtectionDomain protectionDomain,
                 byte[] classfileBuffer)
                 throws IllegalClassFormatException

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:: IllegalClassFormatException - If the input does not represent a well-formed class file