org.unitils.mock.core.proxy

Class CloneUtil

java.lang.Object

org.unitils.mock.core.proxy.CloneUtil

public class CloneUtil
extends Object

Utility class for deep cloning objects. In a deep clone, not only the object itself is cloned, but also all the inner objects.

Author:

Tim Ducheyne, Filip Neven, Kenny Claes

Constructor Summary

Constructors

Constructor and Description
CloneUtil()

Method Summary

Methods

Modifier and Type	Method and Description
protected static Object	cloneArray(Object arrayToClone, Map<Object,Object> cloneCache) Clones the given array and all it's elements.
protected static void	cloneFields(Class<?> clazz, Object instanceToClone, Object clonedInstance, Map<Object,Object> cloneCache) Clones all values in all fields of the given class and superclasses.
protected static Object	cloneObject(Object instanceToClone, Map<Object,Object> cloneCache) Actual implementation of the cloning.
static <T> T	createDeepClone(T object) Creates a deep clone of the given object.
protected static Object	createInstanceUsingClone(Object instanceToClone) If the given value is cloneable and the cloning succeeds, the clone is returned, else null is returned.
protected static Object	createInstanceUsingObjenesis(Object instanceToClone) Tries to create an instance of the same type as the given value using Objenesis.
protected static boolean	isImmutable(Object instanceToClone)
protected static boolean	isJdkClass(Object instanceToClone)

Methods inherited from class java.lang.Object

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

Constructor Detail

CloneUtil

public CloneUtil()

Method Detail

createDeepClone

public static <T> T createDeepClone(T object)

Creates a deep clone of the given object. If for some reason, the clone cannot be made, a warning is logged and the object itself will be returned. This is also true for all inner objects. If an inner object cannot be cloned, the object itself is used instead.

Parameters:

object - The object to clone

Returns:

The cloned instance

cloneObject

protected static Object cloneObject(Object instanceToClone,
                 Map<Object,Object> cloneCache)
                             throws Throwable

Actual implementation of the cloning. It will try several ways to clone the object. First it will look for the simple cases: null, primitives, immutables... If not it will check whether it's an array and clone it using the cloneArray(java.lang.Object, java.util.Map<java.lang.Object, java.lang.Object>) method. Finally it will see whether the object is cloneable and the clone method can be used. If not, Objenisis is used to create the instance. The last step is to recursively do the same operation for the inner fields. An object is cloned once. All created clones are put in a cache and if an object is to be cloned a second time, the cached instance is used. This way the object graph is preserved.

Parameters:

instanceToClone - The instance, not null

cloneCache - The cached clones, not null

Returns:

The clone, the instance to clone if the clone could not be made

Throws:

Throwable

isImmutable

protected static boolean isImmutable(Object instanceToClone)

Parameters:

instanceToClone - The instance, not null

Returns:

True if the instance is immutable, e.g. a primitive

isJdkClass

protected static boolean isJdkClass(Object instanceToClone)

Parameters:

instanceToClone - The instance, not null

Returns:

True if the instance is should not be cloned, e.g. a java lang class or a data source

createInstanceUsingClone

protected static Object createInstanceUsingClone(Object instanceToClone)

If the given value is cloneable and the cloning succeeds, the clone is returned, else null is returned.

Parameters:

instanceToClone - The instance, not null

Returns:

The clone if it could be cloned, else null

createInstanceUsingObjenesis

protected static Object createInstanceUsingObjenesis(Object instanceToClone)

Tries to create an instance of the same type as the given value using Objenesis.

Parameters:

instanceToClone - The instance, not null

Returns:

The new instance if it could be created, else null

cloneFields

protected static void cloneFields(Class<?> clazz,
               Object instanceToClone,
               Object clonedInstance,
               Map<Object,Object> cloneCache)
                           throws Throwable

Clones all values in all fields of the given class and superclasses.

Parameters:

clazz - The current class

instanceToClone - The instance, not null

clonedInstance - The clone, not null

cloneCache - The cached clones, not null

Throws:

Throwable

cloneArray

protected static Object cloneArray(Object arrayToClone,
                Map<Object,Object> cloneCache)
                            throws Throwable

Clones the given array and all it's elements.

Parameters:

arrayToClone - The array, not null

cloneCache - The cached clones, not null

Returns:

The cloned array, not null

Throws:

Throwable