org.javers.core.diff

Class Diff

java.lang.Object

org.javers.core.diff.Diff

All Implemented Interfaces:

Visitable<ChangeVisitor>

public class Diff
extends Object
implements Visitable<ChangeVisitor>

Diff is a set of (atomic) changes between two graphs of objects.

Typically it is used to capture and trace changes made by user on his domain data. In this case diff is done between previous and current state of a bunch of domain objects.

Diff holds following data:

• who did change the data - #getAuthor()
• when the change was made - #getDiffDate()
• list of atomic changes between two graphs

Hints for JaversRepository implementation

• In Domain-driven design language, Diff is an aggregate, while Change is a Value Object.
• After persisting in database, Diff is considered immutable so it can not be updated.
• Since Diff is an aggregate it can be neatly persisted in document database like MongoDB.
• Persisting Diff in any kind of database is easy. Javers provides flexible JSON serialization/deserialization engine, designed as abstraction layer between Java types and specific database types.
• Essentially, object-oriented data are persisted as JSON.

Author:

bartosz walacik

See Also:

JsonConverter

Method Summary

Methods

Modifier and Type	Method and Description
void	accept(ChangeVisitor changeVisitor)
Map<Class<? extends Change>,Integer>	countByType()
List<Change>	getChanges()
boolean	hasChanges()
String	toString()

Methods inherited from class java.lang.Object

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

Method Detail

getChanges

public List<Change> getChanges()

Returns:

unmodifiable list

hasChanges

public boolean hasChanges()

accept

public void accept(ChangeVisitor changeVisitor)

Specified by:

accept in interface Visitable<ChangeVisitor>

toString

public String toString()

Overrides:

toString in class Object

countByType

public Map<Class<? extends Change>,Integer> countByType()