net.sf.mmm.util.lang.api

Class AbstractEqualsChecker<VALUE>

java.lang.Object

net.sf.mmm.util.lang.api.AbstractEqualsChecker<VALUE>

Type Parameters:

VALUE - is the generic type of the values to check.

All Implemented Interfaces:

Serializable, EqualsChecker<VALUE>

Direct Known Subclasses:

EqualsCheckerArray, EqualsCheckerCollection, EqualsCheckerIsEqual, EqualsCheckerIsSame

public abstract class AbstractEqualsChecker<VALUE>
extends Object
implements EqualsChecker<VALUE>, Serializable

This is the abstract base implementation of EqualsChecker. It contains the handling of null values.

Since:

3.0.0

Author:

Joerg Hohwiller (hohwille at users.sourceforge.net)

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
private static long	serialVersionUID

Constructor Summary

Constructors

Constructor and Description
AbstractEqualsChecker() The constructor.

Method Summary

Modifier and Type	Method and Description
boolean	isEqual(VALUE value1, VALUE value2) This method determines if the two given objects are equal to each other in a way semantically defined by this implementation.
protected abstract boolean	isEqualNotNull(VALUE value1, VALUE value2) Called from isEqual(Object, Object) if objects are both NOT same and NOT null.

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

Constructor Detail

AbstractEqualsChecker

public AbstractEqualsChecker()

The constructor.

Method Detail

isEqual

public final boolean isEqual(VALUE value1,
                             VALUE value2)

Description copied from interface: EqualsChecker

This method determines if the two given objects are equal to each other in a way semantically defined by this implementation. An implementation must fulfill the contract of the method Object.equals(Object). This means it is:

• reflexive: isEquals(x, x) == true, especially: isEquals(null, null) == true
• symmetric: isEquals(x, y) == isEquals(y, x)
• transitive: (isEquals(x, y) == isEquals(y, z) == true) implies isEquals(x, z)
• consistent: multiple invocations of isEquals(x, y) will always return the same result if x and y are unchanged.
• null-compatible: for all x != null: isEquals(x, null) == isEquals(null, x) == false

Specified by:

isEqual in interface EqualsChecker<VALUE>

Parameters:

value1 - is the first value.

value2 - is the second value.

Returns:

true if both values are null or both are NOT null and equal to each other in the way defined by this EqualsChecker implementation, false otherwise.

isEqualNotNull

protected abstract boolean isEqualNotNull(VALUE value1,
                                          VALUE value2)

Called from isEqual(Object, Object) if objects are both NOT same and NOT null.

Parameters:

value1 - is the first value to check.

value2 - is the first value to check.

Returns:

true if the given values are considered as equal, false otherwise.