com.helger.commons.equals

Class EqualsHelper

java.lang.Object

com.helger.commons.equals.EqualsHelper

@Immutable
public final class EqualsHelper
extends Object

A small helper class that provides helper methods for easy equals method generation

Author:

Philip Helger

Method Summary

Modifier and Type	Method and Description
static boolean	equals(boolean aObj1, boolean aObj2) Check if two values are equal.
static boolean	equals(byte aObj1, byte aObj2) Check if two values are equal.
static boolean	equals(char aObj1, char aObj2) Check if two values are equal.
static boolean	equals(double aObj1, double aObj2) Check if two double values are equal.
static boolean	equals(float aObj1, float aObj2) Check if two float values are equal.
static boolean	equals(int aObj1, int aObj2) Check if two values are equal.
static boolean	equals(long aObj1, long aObj2) Check if two values are equal.
static boolean	equals(Object aObj1, Object aObj2) Check if two values are equal.
static boolean	equals(short aObj1, short aObj2) Check if two values are equal.
static boolean	equalsAsList(Object aObj1, Object aObj2) This is a sanity method that first calls CollectionHelper.getAsList(Object) on both objects an than calls equalsCollectionOnly(Collection, Collection) on the collections.
static boolean	equalsCollection(Object aObj1, Object aObj2) Check if the content of the passed containers is equal.
static <T> boolean	equalsCollectionOnly(Collection<T> aCont1, Collection<?> aCont2)
static <T> boolean	equalsCustom(T aObj1, T aObj2, BiPredicate<T,T> aPredicate) Perform an equals check with a custom predicate that is only invoked, if both objects are non-null.
static <T> boolean	equalsEumeration(Enumeration<T> aEnum1, Enumeration<?> aEnum2)
static boolean	equalsIgnoreCase(String sObj1, String sObj2) Check if the passed strings are equals case insensitive handling null appropriately.
static <T> boolean	equalsIterator(Iterator<T> aIter1, Iterator<?> aIter2)
static <K,V> boolean	equalsMap(Map<K,V> aCont1, Map<?,?> aCont2)
static <T> boolean	equalsSet(Set<T> aCont1, Set<?> aCont2)
static <T> boolean	identityEqual(T aObj1, T aObj2) The only place where objects are compared by identity.

Methods inherited from class java.lang.Object

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

Method Detail

identityEqual

public static <T> boolean identityEqual(@Nullable
                                        T aObj1,
                                        @Nullable
                                        T aObj2)

The only place where objects are compared by identity.

Type Parameters:

T - Type to check.

Parameters:

aObj1 - First object. May be null.

aObj2 - Second object. May be null.

Returns:

true if both objects are null or reference the same object.

equals

public static boolean equals(boolean aObj1,
                             boolean aObj2)

Check if two values are equal. This method only exists, so that no type differentiation is needed.

Parameters:

aObj1 - First value

aObj2 - Second value

Returns:

true if they are equal, false otherwise.

equals

public static boolean equals(byte aObj1,
                             byte aObj2)

Check if two values are equal. This method only exists, so that no type differentiation is needed.

Parameters:

aObj1 - First value

aObj2 - Second value

Returns:

true if they are equal, false otherwise.

equals

public static boolean equals(char aObj1,
                             char aObj2)

Check if two values are equal. This method only exists, so that no type differentiation is needed.

Parameters:

aObj1 - First value

aObj2 - Second value

Returns:

true if they are equal, false otherwise.

equals

public static boolean equals(double aObj1,
                             double aObj2)

Check if two double values are equal. This is necessary, because in some cases, the "==" operator returns wrong results.

Parameters:

aObj1 - First double

aObj2 - Second double

Returns:

true if they are equal, false otherwise.

equals

public static boolean equals(float aObj1,
                             float aObj2)

Check if two float values are equal. This is necessary, because in some cases, the "==" operator returns wrong results.

Parameters:

aObj1 - First float

aObj2 - Second float

Returns:

true if they are equal, false otherwise.

equals

public static boolean equals(int aObj1,
                             int aObj2)

Check if two values are equal. This method only exists, so that no type differentiation is needed.

Parameters:

aObj1 - First value

aObj2 - Second value

Returns:

true if they are equal, false otherwise.

equals

public static boolean equals(long aObj1,
                             long aObj2)

Check if two values are equal. This method only exists, so that no type differentiation is needed.

Parameters:

aObj1 - First value

aObj2 - Second value

Returns:

true if they are equal, false otherwise.

equals

public static boolean equals(short aObj1,
                             short aObj2)

Check if two values are equal. This method only exists, so that no type differentiation is needed.

Parameters:

aObj1 - First value

aObj2 - Second value

Returns:

true if they are equal, false otherwise.

equals

public static boolean equals(@Nullable
                             Object aObj1,
                             @Nullable
                             Object aObj2)

Check if two values are equal. This method only exists, so that no type differentiation is needed.

Parameters:

aObj1 - First value

aObj2 - Second value

Returns:

true if they are equal, false otherwise.

See Also:

EqualsImplementationRegistry.areEqual(Object, Object)

equalsIgnoreCase

public static boolean equalsIgnoreCase(@Nullable
                                       String sObj1,
                                       @Nullable
                                       String sObj2)

Check if the passed strings are equals case insensitive handling null appropriately.

Parameters:

sObj1 - First object to compare

sObj2 - Second object to compare

Returns:

true if they are equal case insensitive, false otherwise.

equalsCollectionOnly

public static <T> boolean equalsCollectionOnly(@Nonnull
                                               Collection<T> aCont1,
                                               @Nonnull
                                               Collection<?> aCont2)

equalsMap

public static <K,V> boolean equalsMap(@Nonnull
                                      Map<K,V> aCont1,
                                      @Nonnull
                                      Map<?,?> aCont2)

equalsSet

public static <T> boolean equalsSet(@Nonnull
                                    Set<T> aCont1,
                                    @Nonnull
                                    Set<?> aCont2)

equalsIterator

public static <T> boolean equalsIterator(@Nonnull
                                         Iterator<T> aIter1,
                                         Iterator<?> aIter2)

equalsEumeration

public static <T> boolean equalsEumeration(@Nonnull
                                           Enumeration<T> aEnum1,
                                           Enumeration<?> aEnum2)

equalsCollection

public static boolean equalsCollection(@Nullable
                                       Object aObj1,
                                       @Nullable
                                       Object aObj2)

Check if the content of the passed containers is equal. If the container itself contains nested containers, this method is invoked recursively. For non-container elements, the EqualsImplementationRegistry.areEqual(Object, Object) method is invoked to test for equality!

Parameters:

aObj1 - The first container. May be null.

aObj2 - The second container. May be null.

Returns:

true if both objects are the same, or if they have the same meta type and have the same content.

Throws:

IllegalArgumentException - if one of the arguments is not a container!

equalsAsList

public static boolean equalsAsList(@Nullable
                                   Object aObj1,
                                   @Nullable
                                   Object aObj2)

This is a sanity method that first calls CollectionHelper.getAsList(Object) on both objects an than calls equalsCollectionOnly(Collection, Collection) on the collections. This means that calling this method with the String array ["a", "b"] and the List<String> ("a", "b") will result in a return value of true.

Parameters:

aObj1 - The first object to be compared. May be null.

aObj2 - The second object to be compared. May be null.

Returns:

true if the contents are equal, false otherwise

equalsCustom

public static <T> boolean equalsCustom(@Nullable
                                       T aObj1,
                                       @Nullable
                                       T aObj2,
                                       @Nonnull
                                       BiPredicate<T,T> aPredicate)

Perform an equals check with a custom predicate that is only invoked, if both objects are non-null.

Type Parameters:

T - parameter type

Parameters:

aObj1 - The first object to be compared. May be null.

aObj2 - The second object to be compared. May be null.

aPredicate - The predicate to be invoked, if both objects are non-null. May not be null.

Returns:

true if the contents are equal, false otherwise

Since:

9.4.5