net.sf.colossus.util

Class NullCheckPredicate<T>

java.lang.Object

net.sf.colossus.util.NullCheckPredicate<T>

Type Parameters:

T - The type of objects to check.

All Implemented Interfaces:

Predicate<T>

public class NullCheckPredicate<T>
extends java.lang.Object
implements Predicate<T>

A predicate checking objects on being the null object. This class can be used on its own, returning the boolean value given in its constructor for null values and its opposite for non-null values. In this case new NullCheckPredicate(true) creates a predicate checking for null values, and new NullCheckPredicate(false) creates one to check for values other than null. Alternatively subclasses can overwrite matchesNonNullValue(Object), in which case that determines the value for the non-null objects.

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	nullValue

Constructor Summary

Constructors

Constructor and Description
NullCheckPredicate(boolean nullValue) Creates a new predicate.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	matches(T object) Returns true iff the given object matches the predicate.
protected boolean	matchesNonNullValue(T object) Can be overwritten to apply further checks for values that are not null.

Methods inherited from class java.lang.Object

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

Field Detail

nullValue

private final boolean nullValue

Constructor Detail

NullCheckPredicate

public NullCheckPredicate(boolean nullValue)

Creates a new predicate.

Parameters:

nullValue - The value to return for null.

Method Detail

matches

public final boolean matches(T object)

Description copied from interface: Predicate

Returns true iff the given object matches the predicate. Note that null values are allowed and implementers are to return either true or false for them instead of throwing exceptions.

Specified by:

matches in interface Predicate<T>

Parameters:

object - The object to test. May be null.

Returns:

true iff the object matches.

matchesNonNullValue

protected boolean matchesNonNullValue(T object)

Can be overwritten to apply further checks for values that are not null.

Parameters:

object - The value to check. Not null.

Returns:

True iff the object matches. In the default implementation the opposite of the null value.