com.whitestein.lsps.common.collections

Class Diff<E>

java.lang.Object

com.whitestein.lsps.common.collections.Diff<E>

Type Parameters:

E - the type of an element in the sets

public final class Diff<E>
extends Object

Difference between two sets of the same elements. The result (the sets of added, removed, and unchanged elements) is computed against the first set.

Example of usage:

 Set<Integer> set1 = ...  // { 1, 3, <strong>5</strong>, <strong>7</strong> }
 Set<Integer> set2 = ...  // { <strong>5</strong>, 6, <strong>7</strong>, 8, 9 }
 <strong>Diff<</strong>Integer<strong>> diff</strong> = <strong>Diff.of(</strong>set1, set2<strong>)</strong>;
 Set<Integer> added = <strong>diff.added()</strong>  // { 6, 8, 9 }
 Set<Integer> removed = <strong>diff.removed()</strong>  // { 1, 3 }
 Set<Integer> unchanged = <strong>diff.unchanged()</strong>  // { 5, 7 }
 // set2 == set1 + added - removed
 

Author:

vgr

Method Summary

Modifier and Type	Method and Description
Set<? extends E>	added() Returns the set of elements that are missing in the first set, but are present in the second set (they need to be added into the first set).
static <E> Diff<E>	of(Set<? extends E> set1, Set<? extends E> set2) Returns a Diff instance based on the set1 and the set2 arguments.
Set<? extends E>	removed() Returns the set of elements that are present in the first set, but are missing in the second set (they need to be removed from the first set).
Set<? extends E>	unchanged() Returns the set of elements that exist in both sets being compared.

Methods inherited from class java.lang.Object

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

Method Detail

of

public static <E> Diff<E> of(Set<? extends E> set1,
                             Set<? extends E> set2)

Returns a Diff instance based on the set1 and the set2 arguments.

Type Parameters:

E - the type of an element in the sets

Parameters:

set1 - the elements of the first set. All the results (added , removed, unchanged) are computed against this set. Cannot be null

set2 - the elements of the second set. Cannot be null

Returns:

a Diff instance

added

public Set<? extends E> added()

Returns the set of elements that are missing in the first set, but are present in the second set (they need to be added into the first set).

Returns:

the set of elements that need to be added into the first set

removed

public Set<? extends E> removed()

Returns the set of elements that are present in the first set, but are missing in the second set (they need to be removed from the first set).

Returns:

the set of elements that need to be removed from the first set

unchanged

public Set<? extends E> unchanged()

Returns the set of elements that exist in both sets being compared.

Returns:

the set of elements that exist in both sets