org.eclipse.persistence.dynamic

Class DynamicClassWriter

java.lang.Object

org.eclipse.persistence.dynamic.DynamicClassWriter

All Implemented Interfaces:

EclipseLinkClassWriter

public class DynamicClassWriter
extends java.lang.Object
implements EclipseLinkClassWriter

Write the byte codes of a dynamic entity class. The class writer will create the byte codes for a dynamic class that subclasses any provided class replicating its constructors and writeReplace method (if one exists).

The intent is to provide a common writer for dynamic JPA entities but also allow for subclasses of this to be used in more complex writing situations such as SDO and DBWS.

Instances of this class and any subclasses are maintained within the DynamicClassLoader.getClassWriters() and DynamicClassLoader.defaultWriter for the life of the class loader so it is important that no unnecessary state be maintained that may effect memory usage.

Since:

EclipseLink 1.2

Author:

dclarke, mnorman

Field Summary

Fields

Modifier and Type	Field and Description
static int[]	ICONST

Constructor Summary

Constructors

Constructor and Description
DynamicClassWriter()
DynamicClassWriter(java.lang.Class<?> parentClass)
DynamicClassWriter(java.lang.String parentClassName) Create using a loader and class name so that the parent class can be lazily loaded when the writer is used to generate a dynamic class.

Method Summary

Methods

Modifier and Type	Method and Description
java.lang.Class<?>	getParentClass()
java.lang.String	getParentClassName()
boolean	isCompatible(EclipseLinkClassWriter writer) Verify that the provided writer is compatible with the current writer.
java.lang.String	toString()
byte[]	writeClass(DynamicClassLoader loader, java.lang.String className)

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

ICONST

public static int[] ICONST

Constructor Detail

DynamicClassWriter

public DynamicClassWriter()

DynamicClassWriter

public DynamicClassWriter(java.lang.Class<?> parentClass)

DynamicClassWriter

public DynamicClassWriter(java.lang.String parentClassName)

Create using a loader and class name so that the parent class can be lazily loaded when the writer is used to generate a dynamic class.

The loader must not be null and the parentClassName must not be null and not an empty String. The parentClassName will be converted to a class using the provided loader lazily.

See Also:

getParentClass(), DynamicException.illegalDynamicClassWriter(DynamicClassLoader, String)

Method Detail

getParentClass

public java.lang.Class<?> getParentClass()

Specified by:

getParentClass in interface EclipseLinkClassWriter

getParentClassName

public java.lang.String getParentClassName()

Specified by:

getParentClassName in interface EclipseLinkClassWriter

writeClass

public byte[] writeClass(DynamicClassLoader loader,
                java.lang.String className)
                  throws java.lang.ClassNotFoundException

Specified by:

writeClass in interface EclipseLinkClassWriter

Throws:

java.lang.ClassNotFoundException

isCompatible

public boolean isCompatible(EclipseLinkClassWriter writer)

Verify that the provided writer is compatible with the current writer. Returning true means that the bytes that would be created using this writer are identical with what would come from the provided writer.

Used in DynamicClassLoader#addClass(String, DynamicClassWriter) to verify if a duplicate request of the same className can proceed and return the same class that may already exist.

Specified by:

isCompatible in interface EclipseLinkClassWriter

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object