org.objenesis.instantiator.util

Class ClassDefinitionUtils

java.lang.Object

org.objenesis.instantiator.util.ClassDefinitionUtils

public final class ClassDefinitionUtils
extends Object

Helper class for ProxyObjectInstantiator. We can see the details of a class specification here

Author:

Henri Tremblay

Field Summary

Fields

Modifier and Type	Field and Description
static int	ACC_ABSTRACT
static int	ACC_ANNOTATION
static int	ACC_ENUM
static int	ACC_FINAL
static int	ACC_INTERFACE
static int	ACC_PUBLIC
static int	ACC_SUPER
static int	ACC_SYNTHETIC
static int	CONSTANT_Class
static int	CONSTANT_Double
static int	CONSTANT_Fieldref
static int	CONSTANT_Float
static int	CONSTANT_Integer
static int	CONSTANT_InterfaceMethodref
static int	CONSTANT_InvokeDynamic
static int	CONSTANT_Long
static int	CONSTANT_MethodHandle
static int	CONSTANT_Methodref
static int	CONSTANT_MethodType
static int	CONSTANT_NameAndType
static int	CONSTANT_String
static int	CONSTANT_Utf8
static byte[]	MAGIC
static byte	OPS_aload_0
static byte	OPS_areturn
static byte	OPS_dup
static byte	OPS_invokespecial
static byte	OPS_new
static byte	OPS_return
static byte[]	VERSION

Method Summary

Modifier and Type	Method and Description
static <T> Class<T>	defineClass(String className, byte[] b, Class<?> neighbor, ClassLoader loader) Define a class in the provided class loader from the array of bytes.
static byte[]	readClass(String className) Read the bytes of a class from the classpath
static void	writeClass(String fileName, byte[] bytes) Write all class bytes to a file.

Methods inherited from class java.lang.Object

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

Field Detail

OPS_aload_0

public static final byte OPS_aload_0

See Also:

Constant Field Values

OPS_invokespecial

public static final byte OPS_invokespecial

See Also:

Constant Field Values

OPS_return

public static final byte OPS_return

See Also:

Constant Field Values

OPS_new

public static final byte OPS_new

See Also:

Constant Field Values

OPS_dup

public static final byte OPS_dup

See Also:

Constant Field Values

OPS_areturn

public static final byte OPS_areturn

See Also:

Constant Field Values

CONSTANT_Utf8

public static final int CONSTANT_Utf8

See Also:

Constant Field Values

CONSTANT_Integer

public static final int CONSTANT_Integer

See Also:

Constant Field Values

CONSTANT_Float

public static final int CONSTANT_Float

See Also:

Constant Field Values

CONSTANT_Long

public static final int CONSTANT_Long

See Also:

Constant Field Values

CONSTANT_Double

public static final int CONSTANT_Double

See Also:

Constant Field Values

CONSTANT_Class

public static final int CONSTANT_Class

See Also:

Constant Field Values

CONSTANT_String

public static final int CONSTANT_String

See Also:

Constant Field Values

CONSTANT_Fieldref

public static final int CONSTANT_Fieldref

See Also:

Constant Field Values

CONSTANT_Methodref

public static final int CONSTANT_Methodref

See Also:

Constant Field Values

CONSTANT_InterfaceMethodref

public static final int CONSTANT_InterfaceMethodref

See Also:

Constant Field Values

CONSTANT_NameAndType

public static final int CONSTANT_NameAndType

See Also:

Constant Field Values

CONSTANT_MethodHandle

public static final int CONSTANT_MethodHandle

See Also:

Constant Field Values

CONSTANT_MethodType

public static final int CONSTANT_MethodType

See Also:

Constant Field Values

CONSTANT_InvokeDynamic

public static final int CONSTANT_InvokeDynamic

See Also:

Constant Field Values

ACC_PUBLIC

public static final int ACC_PUBLIC

See Also:

Constant Field Values

ACC_FINAL

public static final int ACC_FINAL

See Also:

Constant Field Values

ACC_SUPER

public static final int ACC_SUPER

See Also:

Constant Field Values

ACC_INTERFACE

public static final int ACC_INTERFACE

See Also:

Constant Field Values

ACC_ABSTRACT

public static final int ACC_ABSTRACT

See Also:

Constant Field Values

ACC_SYNTHETIC

public static final int ACC_SYNTHETIC

See Also:

Constant Field Values

ACC_ANNOTATION

public static final int ACC_ANNOTATION

See Also:

Constant Field Values

ACC_ENUM

public static final int ACC_ENUM

See Also:

Constant Field Values

MAGIC

public static final byte[] MAGIC

VERSION

public static final byte[] VERSION

Method Detail

defineClass

public static <T> Class<T> defineClass(String className,
                                       byte[] b,
                                       Class<?> neighbor,
                                       ClassLoader loader)
                                throws Exception

Define a class in the provided class loader from the array of bytes. Inspired by cglib ReflectUtils.defineClass

Type Parameters:

T - type of the class returned

Parameters:

className - class name in the format org.objenesis.MyClass

b - bytes representing the class

neighbor - a class in the same package as the loaded class

loader - the class loader where the class will be loaded

Returns:

the newly loaded class

Throws:

Exception - whenever something goes wrong

readClass

public static byte[] readClass(String className)
                        throws IOException

Read the bytes of a class from the classpath

Parameters:

className - full class name including the package

Returns:

the bytes representing the class

Throws:

IllegalArgumentException - if the class is longer than 2500 bytes

IOException - if we fail to read the class

writeClass

public static void writeClass(String fileName,
                              byte[] bytes)
                       throws IOException

Write all class bytes to a file.

Parameters:

fileName - file where the bytes will be written

bytes - bytes representing the class

Throws:

IOException - if we fail to write the class