Package net.shibboleth.shared.logic

Class PredicateSupport

java.lang.Object

net.shibboleth.shared.logic.PredicateSupport

public final class PredicateSupport
extends Object

Helper class for constructing predicates. Especially useful for creating internal DSLs via Java's static method import mechanism.

Constructor Summary

Constructors

Modifier	Constructor	Description
private	PredicateSupport()	Constructor.

Method Summary

Modifier and Type	Method	Description
static <T> Predicate<Iterable<T>>	allMatch(Predicate<T> target)	Creates a predicate that checks that all elements of an Iterable matches a given target predicate.
static <T> Predicate<T>	alwaysFalse()	Creates a predicate that is always false.
static <T> Predicate<T>	alwaysTrue()	Creates a predicate that is always true.
static <T> Predicate<T>	and(Iterable<? extends Predicate<? super T>> components)	Returns a predicate that evaluates to true if each of its components evaluates to true.
static <T> Predicate<T>	and(Predicate<? super T>... components)	Returns a predicate that evaluates to true if each of its components evaluates to true.
static <T> Predicate<T>	and(Predicate<? super T> first, Predicate<? super T> second)	Returns a predicate that evaluates to true if each of its components evaluates to true.
static <T> Predicate<Iterable<T>>	anyMatch(Predicate<T> target)	Creates a predicate that checks that any element in an Iterable matches a given target predicate.
static Predicate<CharSequence>	caseInsensitiveMatch(String target)	Creates a predicate that checks if a given CharSequence matches a target string while ignoring case.
static <T> Predicate<T>	constant(boolean flag)	Returns a predicate that returns the value of an input parameter.
static <T> Predicate<T>	fromFunction(Function<T,Boolean> function, Predicate<? super T> defValue)	Creates a predicate that applies a function to an input and returns its result, or a default value if null.
static <T> boolean	isAlwaysFalse(Predicate<T> p)	Returns true iff the input parameter is the result of calling alwaysFalse().
static <T> boolean	isAlwaysTrue(Predicate<T> p)	Returns true iff the input parameter is the result of calling alwaysTrue().
static <T> Predicate<T>	not(Predicate<? super T> predicate)	Returns a predicate that evaluates to true if the given predicate evaluates to false.
static <T> Predicate<T>	or(Iterable<? extends Predicate<? super T>> components)	Returns a predicate that evaluates to true if any one of its components evaluates to true.
static <T> Predicate<T>	or(Predicate<? super T>... components)	Returns a predicate that evaluates to true if any one of its components evaluates to true.
static <T> Predicate<T>	or(Predicate<? super T> first, Predicate<? super T> second)	Returns a predicate that evaluates to true if any one of its components evaluates to true.

Methods inherited from class java.lang.Object

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

Constructor Details

PredicateSupport

private PredicateSupport()

Constructor.

Method Details

alwaysTrue

@Nonnull
public static <T> Predicate<T> alwaysTrue()

Creates a predicate that is always true.

Type Parameters:

T - input type

Returns:

the constructed predicate

Since:

9.0.0

alwaysFalse

@Nonnull
public static <T> Predicate<T> alwaysFalse()

Creates a predicate that is always false.

Type Parameters:

T - input type

Returns:

the constructed predicate

Since:

9.0.0

isAlwaysTrue

public static <T> boolean isAlwaysTrue(@Nonnull
 Predicate<T> p)

Returns true iff the input parameter is the result of calling alwaysTrue().

Type Parameters:

T - predicate type

Parameters:

p - candidate to test

Returns:

true iff the input parameter is the result of calling alwaysTrue().

Since:

9.0.0

isAlwaysFalse

public static <T> boolean isAlwaysFalse(@Nonnull
 Predicate<T> p)

Returns true iff the input parameter is the result of calling alwaysFalse().

Type Parameters:

T - predicate type

Parameters:

p - candidate to test

Returns:

true iff the input parameter is the result of calling alwaysFalse().

Since:

9.0.0

constant

@Nonnull
public static <T> Predicate<T> constant(boolean flag)

Returns a predicate that returns the value of an input parameter.

Type Parameters:

T - input type

Parameters:

flag - flag controlling result of predicate

Returns:

the newly constructed predicate

Since:

9.0.0

allMatch

@Nonnull
public static <T> Predicate<Iterable<T>> allMatch(@Nonnull
 Predicate<T> target)

Creates a predicate that checks that all elements of an Iterable matches a given target predicate.

Type Parameters:

T - type of objects in the iterable and that the target operates upon

Parameters:

target - predicate used to check each element in the iterable

Returns:

the constructed predicate

anyMatch

@Nonnull
public static <T> Predicate<Iterable<T>> anyMatch(@Nonnull
 Predicate<T> target)

Creates a predicate that checks that any element in an Iterable matches a given target predicate.

Type Parameters:

T - type of objects in the iterable and that the target operates upon

Parameters:

target - predicate used to check each element in the iterable

Returns:

the constructed predicate

caseInsensitiveMatch

@Nonnull
public static Predicate<CharSequence> caseInsensitiveMatch(@Nonnull
 String target)

Creates a predicate that checks if a given CharSequence matches a target string while ignoring case.

Parameters:

target - the target string to match against

Returns:

the constructed predicate

fromFunction

@Nonnull
public static <T> Predicate<T> fromFunction(@Nonnull
 Function<T,Boolean> function,
 @Nonnull
 Predicate<? super T> defValue)

Creates a predicate that applies a function to an input and returns its result, or a default value if null.

Type Parameters:

T - type of function input

Parameters:

function - function to apply to input

defValue - default predicate to apply if function returns null

Returns:

a predicate adapter

Since:

7.4.0

not

@Nonnull
public static <T> Predicate<T> not(@Nonnull
 Predicate<? super T> predicate)

Returns a predicate that evaluates to true if the given predicate evaluates to false.

Type Parameters:

T - predicate input type

Parameters:

predicate - the predicate to negate

Returns:

the negated predicate

and

@Nonnull
public static <T> Predicate<T> and(@Nonnull
 Iterable<? extends Predicate<? super T>> components)

Returns a predicate that evaluates to true if each of its components evaluates to true. The components are evaluated in order, and evaluation will be "short-circuited" as soon as a false predicate is found. It defensively copies the iterable passed in, so future changes to it won't alter the behavior of this predicate. If components is empty, the returned predicate will always evaluate to true.

Type Parameters:

T - predicate input type

Parameters:

components - the predicates to combine

Returns:

the composite predicate

and

@SafeVarargs
@Nonnull
public static <T> Predicate<T> and(@Nonnull
 Predicate<? super T>... components)

Returns a predicate that evaluates to true if each of its components evaluates to true. The components are evaluated in order, and evaluation will be "short-circuited" as soon as a false predicate is found. It defensively copies the iterable passed in, so future changes to it won't alter the behavior of this predicate. If components is empty, the returned predicate will always evaluate to true.

Type Parameters:

T - predicate input type

Parameters:

components - the predicates to combine

Returns:

the composite predicate

and

@Nonnull
public static <T> Predicate<T> and(@Nonnull
 Predicate<? super T> first,
 @Nonnull
 Predicate<? super T> second)

Returns a predicate that evaluates to true if each of its components evaluates to true. The components are evaluated in order, and evaluation will be "short-circuited" as soon as a false predicate is found. It defensively copies the iterable passed in, so future changes to it won't alter the behavior of this predicate. If components is empty, the returned predicate will always evaluate to true.

Type Parameters:

T - predicate input type

Parameters:

first - the first predicate

second - the second predicate

Returns:

the composite predicate

or

@Nonnull
public static <T> Predicate<T> or(@Nonnull
 Iterable<? extends Predicate<? super T>> components)

Returns a predicate that evaluates to true if any one of its components evaluates to true. The components are evaluated in order, and evaluation will be "short-circuited" as soon as a true predicate is found. It defensively copies the iterable passed in, so future changes to it won't alter the behavior of this predicate. If components is empty, the returned predicate will always evaluate to false.

Type Parameters:

T - predicate input type

Parameters:

components - the predicates to combine

Returns:

the composite predicate

or

@SafeVarargs
@Nonnull
public static <T> Predicate<T> or(@Nonnull
 Predicate<? super T>... components)

Returns a predicate that evaluates to true if any one of its components evaluates to true. The components are evaluated in order, and evaluation will be "short-circuited" as soon as a true predicate is found. It defensively copies the iterable passed in, so future changes to it won't alter the behavior of this predicate. If components is empty, the returned predicate will always evaluate to false.

Type Parameters:

T - predicate input type

Parameters:

components - the predicates to combine

Returns:

the composite predicate

or

@Nonnull
public static <T> Predicate<T> or(@Nonnull
 Predicate<? super T> first,
 @Nonnull
 Predicate<? super T> second)

Returns a predicate that evaluates to true if any one of its components evaluates to true. The components are evaluated in order, and evaluation will be "short-circuited" as soon as a true predicate is found. It defensively copies the iterable passed in, so future changes to it won't alter the behavior of this predicate. If components is empty, the returned predicate will always evaluate to false.

Type Parameters:

T - predicate input type

Parameters:

first - the first predicate

second - the second predicate

Returns:

the composite predicate