Package org.javers.core.diff.custom

Interface CustomPropertyComparator<T,C extends PropertyChange>

Type Parameters:

T - Custom Type

C - Concrete type of PropertyChange returned by a comparator

All Known Implementing Classes:

CustomBigDecimalComparator

public interface CustomPropertyComparator<T,C extends PropertyChange>

Property-scope comparator bounded to CustomType.

Typically, Custom Types are large structures (like Multimap) or complex objects. For simple values, it's better to use CustomValueComparator.

Implementation should calculate a diff between two objects of given Custom Type.

Examples and doc: https://javers.org/documentation/diff-configuration/#custom-comparators

Usage:

 JaversBuilder.javers().registerCustomComparator(new GuavaCustomComparator(), Multimap.class).build()
 

Method Summary

Modifier and Type	Method	Description
java.util.Optional<C>	compare(T left, T right, GlobalId affectedId, Property property)	Called by JaVers to calculate property-to-property diff between two Custom Type objects.
boolean	equals(T a, T b)	Called by JaVers to calculate collection-to-collection diff, when Custom Type objects are Collection items.

Method Detail

compare

java.util.Optional<C> compare(T left,
                              T right,
                              GlobalId affectedId,
                              Property property)

Called by JaVers to calculate property-to-property diff between two Custom Type objects.

Parameters:

left - left (or old) value

right - right (or current) value

affectedId - Id of domain object being compared

property - property being compared

Returns:

should return Optional.empty() if compared objects are the same

equals

boolean equals(T a,
               T b)

Called by JaVers to calculate collection-to-collection diff, when Custom Type objects are Collection items.

Both equals() and compare() should return consistent results. When compare() returns Optional.empty(), equals() should return false.