org.unitils.reflectionassert

Class ReflectionComparator

java.lang.Object

org.unitils.reflectionassert.ReflectionComparator

public class ReflectionComparator
extends Object

A comparator for comparing two values by reflection.

The actual comparison of the values is implemented as a comparator chain. The chain is passed as an argument during the construction. Each of the comparators in the chain is able to compare some types of values. E.g. a CollectionComparator is able to compare collections, simple values such as integers are compared by the SimpleCasesComparator... A number of 'leniency levels' can also be added to the chain: e.g. the LenientOrderCollectionComparator ignores the actual ordering of 2 collections.

The preferred way of creating new instances is by using the ReflectionComparatorFactory. This factory will make sure that a correct comparator chain is assembled.

A readable report differences can be created using the DifferenceReport.

Author:

Tim Ducheyne, Filip Neven

Field Summary

Fields

Modifier and Type	Field and Description
protected Map<Object,Map<Object,Difference>>	allDifferencesCachedResults
protected List<Comparator>	comparators The comparator chain.
protected Map<Object,Map<Object,Difference>>	firstDifferenceCachedResults A cache of results, so that comparisons are only performed once and infinite loops because of cycles are avoided A different cache is used dependent on whether only the first difference is required or whether we need all differences, since the resulting Difference objects differ.

Constructor Summary

Constructors

Constructor and Description
ReflectionComparator(List<Comparator> comparators) Creates a comparator that will use the given chain.

Method Summary

Methods

Modifier and Type	Method and Description
protected Map<Object,Difference>	getCachedDifference(Object left, boolean onlyFirstDifference)
Difference	getDifference(Object left, Object right) Checks whether there is a difference between the left and right objects.
Difference	getDifference(Object left, Object right, boolean onlyFirstDifference) Checks whether there are differences between the left and right objects.
boolean	isEqual(Object left, Object right) Checks whether there is no difference between the left and right objects.
protected void	saveResultInCache(Object left, Map<Object,Difference> cachedResult, boolean onlyFirstDifference)

Methods inherited from class java.lang.Object

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

Field Detail

comparators

protected List<Comparator> comparators

The comparator chain.

firstDifferenceCachedResults

protected Map<Object,Map<Object,Difference>> firstDifferenceCachedResults

A cache of results, so that comparisons are only performed once and infinite loops because of cycles are avoided A different cache is used dependent on whether only the first difference is required or whether we need all differences, since the resulting Difference objects differ.

allDifferencesCachedResults

protected Map<Object,Map<Object,Difference>> allDifferencesCachedResults

Constructor Detail

ReflectionComparator

public ReflectionComparator(List<Comparator> comparators)

Creates a comparator that will use the given chain.

Parameters:

comparators - The comparator chain, not null

Method Detail

isEqual

public boolean isEqual(Object left,
              Object right)

Checks whether there is no difference between the left and right objects.

Parameters:

left - the left instance

right - the right instance

Returns:

true if there is no difference, false otherwise

getDifference

public Difference getDifference(Object left,
                       Object right)

Checks whether there is a difference between the left and right objects.

Parameters:

left - the left instance

right - the right instance

Returns:

the difference, null if there is no difference

getDifference

public Difference getDifference(Object left,
                       Object right,
                       boolean onlyFirstDifference)

Checks whether there are differences between the left and right objects. This will return the root difference of the whole difference tree containing all the differences between the objects.

Parameters:

left - the left instance

right - the right instance

onlyFirstDifference - True if the comparison should stop at the first differnece

Returns:

the root difference, null if there is no difference

saveResultInCache

protected void saveResultInCache(Object left,
                     Map<Object,Difference> cachedResult,
                     boolean onlyFirstDifference)

getCachedDifference

protected Map<Object,Difference> getCachedDifference(Object left,
                                         boolean onlyFirstDifference)