Package com.sun.ejb.codegen

Class ClassGenerator

java.lang.Object

com.sun.ejb.codegen.ClassGenerator

public final class ClassGenerator
extends Object

This class serves to generate classes, because ...

MethodHandles.Lookup class restricts the generated class to use an already existing class as a source of the package and ProtectionDomain.

Proxy.newProxyInstance(ClassLoader, Class[], java.lang.reflect.InvocationHandler) has another requirements, ie. all referred classes must be loadable by used classloader.

Author:

David Matejcek

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ClassGenerator.ClassDefinitionException	The class wasn't generated.

Method Summary

Modifier and Type	Method	Description
static Class<?>	defineClass(Class<?> anchorClass, String className, byte[] classData)	Calls the MethodHandles.Lookup's defineClass method to create a new class
static Class<?>	defineClass(ClassLoader loader, Class<?> anchorClass, String targetPackageName, String className, byte[] classData)	Decides which method is suitable to define the new class and then uses it.
static Class<?>	defineClass(ClassLoader loader, String className, byte[] classData)	Calls the ClassLoader's protected defineClass method to create a new class
static Class<?>	defineClass(ClassLoader loader, String className, byte[] classData, int offset, int length)	Calls the ClassLoader's protected defineClass method to create a new class
static Class<?>	defineClass(ClassLoader loader, String className, byte[] classData, int offset, int length, ProtectionDomain protectionDomain)	Calls the ClassLoader's protected defineClass method to create a new class
static Class<?>	defineClass(ClassLoader loader, String className, byte[] classData, ProtectionDomain protectionDomain)	Calls the ClassLoader's protected defineClass method to create a new class

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

defineClass

public static Class<?> defineClass(ClassLoader loader,
 Class<?> anchorClass,
 String targetPackageName,
 String className,
 byte[] classData)

Decides which method is suitable to define the new class and then uses it.

Parameters:

loader - the classloader instance used to generate the class

anchorClass - the class used as an "orientation" class. See the MethodHandles.Lookup class for more info.

targetPackageName - the name is used in decision logic; if the anchor class is from a different package, the MethodHandles.Lookup's method is not usable.

className - expected binary name or null

classData - the valid bytes that make up the class data.

Returns:

the new generated class

Throws:

ClassGenerator.ClassDefinitionException - invalid data, missing dependency, or another error related to the class generation

defineClass

public static Class<?> defineClass(Class<?> anchorClass,
 String className,
 byte[] classData)

Calls the MethodHandles.Lookup's defineClass method to create a new class

Parameters:

anchorClass - the class used as an "orientation" class. See the MethodHandles.Lookup class for more info.

className - expected binary name or null

classData - the valid bytes that make up the class data.

Returns:

the new generated class

Throws:

ClassGenerator.ClassDefinitionException - invalid data, missing dependency, or another error related to the class generation

defineClass

public static Class<?> defineClass(ClassLoader loader,
 String className,
 byte[] classData)
                            throws ClassGenerator.ClassDefinitionException

Calls the ClassLoader's protected defineClass method to create a new class

Parameters:

loader - the classloader instance used to generate the class

className - expected binary name or null

classData - the valid bytes that make up the class data.

Returns:

the new generated class

Throws:

ClassGenerator.ClassDefinitionException - invalid data, missing dependency, or another error related to the class generation

defineClass

public static Class<?> defineClass(ClassLoader loader,
 String className,
 byte[] classData,
 int offset,
 int length)
                            throws ClassGenerator.ClassDefinitionException

Calls the ClassLoader's protected defineClass method to create a new class

Parameters:

loader - the classloader instance used to generate the class

className - expected binary name or null

classData - the valid bytes that make up the class data.

offset - The start offset in b of the class data

length - The length of the class data

Returns:

the new generated class

Throws:

ClassGenerator.ClassDefinitionException - invalid data, missing dependency, or another error related to the class generation

defineClass

public static Class<?> defineClass(ClassLoader loader,
 String className,
 byte[] classData,
 ProtectionDomain protectionDomain)
                            throws ClassGenerator.ClassDefinitionException

Calls the ClassLoader's protected defineClass method to create a new class

Parameters:

loader - the classloader instance used to generate the class

className - expected binary name or null

classData - the valid bytes that make up the class data.

protectionDomain - The ProtectionDomain of the class

Returns:

the new generated class

Throws:

ClassGenerator.ClassDefinitionException - invalid data, missing dependency, or another error related to the class generation

defineClass

public static Class<?> defineClass(ClassLoader loader,
 String className,
 byte[] classData,
 int offset,
 int length,
 ProtectionDomain protectionDomain)
                            throws ClassGenerator.ClassDefinitionException

Calls the ClassLoader's protected defineClass method to create a new class

Parameters:

loader - the classloader instance used to generate the class

className - expected binary name or null

classData - the valid bytes that make up the class data.

offset - The start offset in b of the class data

length - The length of the class data

protectionDomain - The ProtectionDomain of the class

Returns:

the new generated class

Throws:

ClassGenerator.ClassDefinitionException - invalid data, missing dependency, or another error related to the class generation