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.
Method Summary |
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 |
nullValue
private final boolean nullValue
NullCheckPredicate
public NullCheckPredicate(boolean nullValue)
- Creates a new predicate.
- Parameters:
nullValue
- The value to return for null.
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.