com.helger.commons.equals

Class ContainerEqualsUtils

java.lang.Object

com.helger.commons.equals.ContainerEqualsUtils

public final class ContainerEqualsUtils
extends Object

A special equals helper class that handles collections and container classes. The different to the reqular EqualsUtils and EqualsImplementationRegistry methods is, that the methods contained in here are not strictly obeying to the equals contract, as the implementation classes must not match - only the content is relevant.

Author:

Philip Helger

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ContainerEqualsUtils.EContainerType This enum differentiates the different meta container types.

Method Summary

Modifier and Type	Method and Description
static boolean	equals(Object aObj1, Object aObj2) Check if the content of the passed containers is equal.
static boolean	equalsAsList(Object aObj1, Object aObj2) This is a sanity method that first calls getAsList(Object) on both objects an than calls equals(Object, Object) on the collections.
static List<?>	getAsList(Object aObj) Get the passed object as a List object.
static ContainerEqualsUtils.EContainerType	getContainerTypeOfClass(Class<?> aClass)
static ContainerEqualsUtils.EContainerType	getContainerTypeOfObject(Object aObj)
static boolean	isContainerClass(Class<?> aClass)
static boolean	isContainerObject(Object aObj)

Methods inherited from class java.lang.Object

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

Method Detail

getContainerTypeOfClass

@Nullable
public static ContainerEqualsUtils.EContainerType getContainerTypeOfClass(@Nullable
                                                                                     Class<?> aClass)

getContainerTypeOfObject

@Nullable
public static ContainerEqualsUtils.EContainerType getContainerTypeOfObject(@Nullable
                                                                                      Object aObj)

isContainerClass

public static boolean isContainerClass(@Nullable
                                       Class<?> aClass)

isContainerObject

public static boolean isContainerObject(@Nullable
                                        Object aObj)

equals

public static boolean equals(@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

aObj2 - The second container

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!

getAsList

@Nonnull
public static List<?> getAsList(@Nonnull
                                          Object aObj)

Get the passed object as a List object. This is helpful in case you want to compare the String array ["a", "b"] with the List<String> ("a", "b") If the passed object is not a recognized. container type, than a new list with one element is created!

Parameters:

aObj - The object to be converted. May not be null.

Returns:

The object as a collection. Never null.

equalsAsList

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

This is a sanity method that first calls getAsList(Object) on both objects an than calls equals(Object, Object) 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

aObj2 - The second object to be compared

Returns:

true if the contents are equal, false otherwise