net.sf.basedb.util
Class EqualsHelper

java.lang.Object
  net.sf.basedb.util.EqualsHelper

public class EqualsHelper
extends Object

Helper class for implementing equals and hash code calculations in classes.

Since:

2.15

Author:

nicklas

Constructor Summary

EqualsHelper()

Method Summary

static boolean	equals(Object o1, Object o2) Check if two objects are equal according to their equals implementation.
static int	hashCode(Object o) Get the hashcode for an object.
static <T> int	hashCode(T... objects) Hashcode calculation for an array of objects that doesn't depend on the position in the array.
static <T> boolean	invariantEquals(T[] a1, T[] a2) Checks if two arrays contains equal elements disregarding their positions in the array.

Methods inherited from class java.lang.Object

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

Constructor Detail

EqualsHelper

public EqualsHelper()

Method Detail

equals

public static boolean equals(Object o1,
                             Object o2)

Check if two objects are equal according to their equals implementation. This method is safe to use with null values and returns true if both objects are null. Otherwise, it calls o1.equals(o2).

Parameters:

o1 - The first object

o2 - The second object

Returns:

TRUE if the objects are equal

hashCode

public static int hashCode(Object o)

Get the hashcode for an object. This method is safe to use with null and returns 0.

Parameters:

o - The object to get the hash code for

Returns:

The hash code

hashCode

public static <T> int hashCode(T... objects)

Hashcode calculation for an array of objects that doesn't depend on the position in the array. Null objects are ignored.

Parameters:

objects - An array of objects

Returns:

The combined hash code for objects in the array

See Also:

invariantEquals(Object[], Object[])

invariantEquals

public static <T> boolean invariantEquals(T[] a1,
                                          T[] a2)

Checks if two arrays contains equal elements disregarding their positions in the array. Eg. [1, 2] is equal to [2, 1]

Parameters:

a1 - The first array

a2 - The second array

Returns:

TRUE if both arrays contains the same elements