Apache Commons Collections 4.4 · org.apache.commons.collections4.ClosureUtils

Access	Constructor and Description
private	ClosureUtils() This class is not normally instantiated.

Method Summary

Modifier and Type	Method and Description
public static < the type that the closure acts on E> Closure<E>	Returns: the closure asClosure(final Transformer<? super E, ?> the transformer to run each time in the closure, null means nop transformer) Creates a Closure that calls a Transformer each time it is called.
public static < the type that the closure acts on E> Closure<E>	Returns: the `chained` closure chainedClosure(final Closure<? super E>... an array of closures to chain closures) Create a new Closure that calls each closure in turn, passing the result into the next closure.
public static < the type that the closure acts on E> Closure<E>	Returns: the `chained` closure chainedClosure(final Collection<? extends Closure<? super E>> a collection of closures to chain closures) Create a new Closure that calls each closure in turn, passing the result into the next closure.
public static < the type that the closure acts on E> Closure<E>	Returns: the `do-while` closure doWhileClosure(final Closure<? super E> the closure to call repeatedly, not null closure, final Predicate<? super E> the predicate to use as an end of loop test, not null predicate) Creates a Closure that will call the closure once and then repeatedly until the predicate returns false.
public static < the type that the closure acts on E> Closure<E>	Returns: the closure exceptionClosure() Gets a Closure that always throws an exception.
public static < the type that the closure acts on E> Closure<E>	Returns: the `for` closure forClosure(final int the number of times to loop count, final Closure<? super E> the closure to call repeatedly closure) Creates a Closure that will call the closure `count` times.
public static < the type that the closure acts on E> Closure<E>	Returns: the `if` closure ifClosure(final Predicate<? super E> the validating predicate predicate, final Closure<? super E> the closure called if the predicate is true trueClosure) Create a new Closure that calls another closure based on the result of the specified predicate.
public static < the type that the closure acts on E> Closure<E>	Returns: the `switch` closure ifClosure(final Predicate<? super E> the predicate to switch on predicate, final Closure<? super E> the closure called if the predicate is true trueClosure, final Closure<? super E> the closure called if the predicate is false falseClosure) Create a new Closure that calls one of two closures depending on the specified predicate.
public static < the type that the closure acts on E> Closure<E>	Returns: the `invoker` closure invokerClosure(final String the name of the method methodName) Creates a Closure that will invoke a specific method on the closure's input object by reflection.
public static < the type that the closure acts on E> Closure<E>	Returns: the `invoker` closure invokerClosure(final String the name of the method methodName, final Class<?>[] the parameter types paramTypes, final Object[] the arguments args) Creates a Closure that will invoke a specific method on the closure's input object by reflection.
public static < the type that the closure acts on E> Closure<E>	Returns: the closure nopClosure() Gets a Closure that will do nothing.
public static < the type that the closure acts on E> Closure<E>	Returns: the `switch` closure switchClosure(final Predicate<? super E>[] an array of predicates to check, not null predicates, final Closure<? super E>[] an array of closures to call, not null closures) Create a new Closure that calls one of the closures depending on the predicates.
public static < the type that the closure acts on E> Closure<E>	Returns: the `switch` closure switchClosure(final Predicate<? super E>[] an array of predicates to check, not null predicates, final Closure<? super E>[] an array of closures to call, not null closures, final Closure<? super E> the default to call if no predicate matches defaultClosure) Create a new Closure that calls one of the closures depending on the predicates.
public static < the type that the closure acts on E> Closure<E>	Returns: the `switch` closure switchClosure(final Map<Predicate<E>, Closure<E>> a map of predicates to closures predicatesAndClosures) Create a new Closure that calls one of the closures depending on the predicates.
public static < the type that the closure acts on E> Closure<E>	Returns: the closure switchMapClosure(final Map<? extends E, Closure<E>> a map of objects to closures objectsAndClosures) Create a new Closure that uses the input object as a key to find the closure to call.
public static < the type that the closure acts on E> Closure<E>	Returns: the `while` closure whileClosure(final Predicate<? super E> the predicate to use as an end of loop test, not null predicate, final Closure<? super E> the closure to call repeatedly, not null closure) Creates a Closure that will call the closure repeatedly until the predicate returns false.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

ClosureUtils	back to summary
private ClosureUtils() This class is not normally instantiated.

Method Detail

asClosure back to summary

asClosure	back to summary
public static <E> Closure<E> asClosure(final Transformer<? super E, ?> transformer) Creates a Closure that calls a Transformer each time it is called. The transformer will be called using the closure's input object. The transformer's result will be ignored. Parameters <E> the type that the closure acts on transformer:Transformer<? super E, ?> the transformer to run each time in the closure, null means nop Returns:Closure<E> the closure See Also `org.apache.commons.collections4.functors.TransformerClosure`

public static <E> Closure<E> asClosure(final Transformer<? super E, ?> transformer)

Creates a Closure that calls a Transformer each time it is called. The transformer will be called using the closure's input object. The transformer's result will be ignored.

Parameters

<E>: the type that the closure acts on
transformer:Transformer<? super E, ?>: the transformer to run each time in the closure, null means nop

Returns:Closure<E>

the closure

chainedClosure back to summary

chainedClosure	back to summary
public static <E> Closure<E> chainedClosure(final Closure<? super E>... closures) Create a new Closure that calls each closure in turn, passing the result into the next closure. Parameters <E> the type that the closure acts on closures:Closure<? super E>[] an array of closures to chain Returns:Closure<E> the `chained` closure Exceptions NullPointerException: if the closures array is null if any closure in the array is null See Also `org.apache.commons.collections4.functors.ChainedClosure`

public static <E> Closure<E> chainedClosure(final Closure<? super E>... closures)

Create a new Closure that calls each closure in turn, passing the result into the next closure.

Parameters

<E>: the type that the closure acts on
closures:Closure<? super E>[]: an array of closures to chain

Returns:Closure<E>

the chained closure

Exceptions

NullPointerException:

if the closures array is null
if any closure in the array is null

chainedClosure back to summary

chainedClosure	back to summary
public static <E> Closure<E> chainedClosure(final Collection<? extends Closure<? super E>> closures) Create a new Closure that calls each closure in turn, passing the result into the next closure. The ordering is that of the iterator() method on the collection. Parameters <E> the type that the closure acts on closures:Collection<? extends Closure<? super E>> a collection of closures to chain Returns:Closure<E> the `chained` closure Exceptions NullPointerException: if the closures collection is null if any closure in the collection is null IllegalArgumentException: if the closures collection is empty See Also `org.apache.commons.collections4.functors.ChainedClosure`

public static <E> Closure<E> chainedClosure(final Collection<? extends Closure<? super E>> closures)

Create a new Closure that calls each closure in turn, passing the result into the next closure. The ordering is that of the iterator() method on the collection.

Parameters

<E>: the type that the closure acts on
closures:Collection<? extends Closure<? super E>>: a collection of closures to chain

Returns:Closure<E>

the chained closure

Exceptions

NullPointerException:

if the closures collection is null
if any closure in the collection is null

IllegalArgumentException:

if the closures collection is empty

doWhileClosure back to summary

doWhileClosure	back to summary
public static <E> Closure<E> doWhileClosure(final Closure<? super E> closure, final Predicate<? super E> predicate) Creates a Closure that will call the closure once and then repeatedly until the predicate returns false. Parameters <E> the type that the closure acts on closure:Closure<? super E> the closure to call repeatedly, not null predicate:Predicate<? super E> the predicate to use as an end of loop test, not null Returns:Closure<E> the `do-while` closure Exceptions NullPointerException: if either argument is null See Also `org.apache.commons.collections4.functors.WhileClosure`

public static <E> Closure<E> doWhileClosure(final Closure<? super E> closure, final Predicate<? super E> predicate)

Creates a Closure that will call the closure once and then repeatedly until the predicate returns false.

Parameters

<E>: the type that the closure acts on
closure:Closure<? super E>: the closure to call repeatedly, not null
predicate:Predicate<? super E>: the predicate to use as an end of loop test, not null

Returns:Closure<E>

the do-while closure

Exceptions

NullPointerException:: if either argument is null

exceptionClosure back to summary

exceptionClosure	back to summary
public static <E> Closure<E> exceptionClosure() Gets a Closure that always throws an exception. This could be useful during testing as a placeholder. Parameters <E> the type that the closure acts on Returns:Closure<E> the closure See Also `org.apache.commons.collections4.functors.ExceptionClosure`

public static <E> Closure<E> exceptionClosure()

Gets a Closure that always throws an exception. This could be useful during testing as a placeholder.

Parameters

<E>: the type that the closure acts on

Returns:Closure<E>

the closure

forClosure back to summary

forClosure	back to summary
public static <E> Closure<E> forClosure(final int count, final Closure<? super E> closure) Creates a Closure that will call the closure `count` times. A null closure or zero count returns the `NOPClosure`. Parameters <E> the type that the closure acts on count:int the number of times to loop closure:Closure<? super E> the closure to call repeatedly Returns:Closure<E> the `for` closure See Also `org.apache.commons.collections4.functors.ForClosure`

public static <E> Closure<E> forClosure(final int count, final Closure<? super E> closure)

Creates a Closure that will call the closure count times.

A null closure or zero count returns the NOPClosure.

Parameters

<E>: the type that the closure acts on
count:int: the number of times to loop
closure:Closure<? super E>: the closure to call repeatedly

Returns:Closure<E>

the for closure

ifClosure back to summary

ifClosure	back to summary
public static <E> Closure<E> ifClosure(final Predicate<? super E> predicate, final Closure<? super E> trueClosure) Create a new Closure that calls another closure based on the result of the specified predicate. Parameters <E> the type that the closure acts on predicate:Predicate<? super E> the validating predicate trueClosure:Closure<? super E> the closure called if the predicate is true Returns:Closure<E> the `if` closure Exceptions NullPointerException: if the predicate or closure is null Since 3.2 See Also `org.apache.commons.collections4.functors.IfClosure`

public static <E> Closure<E> ifClosure(final Predicate<? super E> predicate, final Closure<? super E> trueClosure)

Create a new Closure that calls another closure based on the result of the specified predicate.

Parameters

<E>: the type that the closure acts on
predicate:Predicate<? super E>: the validating predicate
trueClosure:Closure<? super E>: the closure called if the predicate is true

Returns:Closure<E>

the if closure

Exceptions

NullPointerException:: if the predicate or closure is null

Since

3.2

ifClosure back to summary

ifClosure	back to summary
public static <E> Closure<E> ifClosure(final Predicate<? super E> predicate, final Closure<? super E> trueClosure, final Closure<? super E> falseClosure) Create a new Closure that calls one of two closures depending on the specified predicate. Parameters <E> the type that the closure acts on predicate:Predicate<? super E> the predicate to switch on trueClosure:Closure<? super E> the closure called if the predicate is true falseClosure:Closure<? super E> the closure called if the predicate is false Returns:Closure<E> the `switch` closure Exceptions NullPointerException: if the predicate or either closure is null See Also `org.apache.commons.collections4.functors.IfClosure`

public static <E> Closure<E> ifClosure(final Predicate<? super E> predicate, final Closure<? super E> trueClosure, final Closure<? super E> falseClosure)

Create a new Closure that calls one of two closures depending on the specified predicate.

Parameters

<E>: the type that the closure acts on
predicate:Predicate<? super E>: the predicate to switch on
trueClosure:Closure<? super E>: the closure called if the predicate is true
falseClosure:Closure<? super E>: the closure called if the predicate is false

Returns:Closure<E>

the switch closure

Exceptions

NullPointerException:: if the predicate or either closure is null

invokerClosure back to summary

invokerClosure	back to summary
public static <E> Closure<E> invokerClosure(final String methodName) Creates a Closure that will invoke a specific method on the closure's input object by reflection. Parameters <E> the type that the closure acts on methodName:String the name of the method Returns:Closure<E> the `invoker` closure Exceptions NullPointerException: if the method name is null See Also `org.apache.commons.collections4.functors.InvokerTransformer`, `org.apache.commons.collections4.functors.TransformerClosure`

public static <E> Closure<E> invokerClosure(final String methodName)

Creates a Closure that will invoke a specific method on the closure's input object by reflection.

Parameters

<E>: the type that the closure acts on
methodName:String: the name of the method

Returns:Closure<E>

the invoker closure

Exceptions

NullPointerException:: if the method name is null

invokerClosure back to summary

invokerClosure	back to summary
public static <E> Closure<E> invokerClosure(final String methodName, final Class<?>[] paramTypes, final Object[] args) Creates a Closure that will invoke a specific method on the closure's input object by reflection. Parameters <E> the type that the closure acts on methodName:String the name of the method paramTypes:Class<?>[] the parameter types args:Object[] the arguments Returns:Closure<E> the `invoker` closure Exceptions NullPointerException: if the method name is null IllegalArgumentException: if the paramTypes and args don't match See Also `org.apache.commons.collections4.functors.InvokerTransformer`, `org.apache.commons.collections4.functors.TransformerClosure`

public static <E> Closure<E> invokerClosure(final String methodName, final Class<?>[] paramTypes, final Object[] args)

Creates a Closure that will invoke a specific method on the closure's input object by reflection.

Parameters

<E>: the type that the closure acts on
methodName:String: the name of the method
paramTypes:Class<?>[]: the parameter types
args:Object[]: the arguments

Returns:Closure<E>

the invoker closure

Exceptions

NullPointerException:: if the method name is null
IllegalArgumentException:: if the paramTypes and args don't match

nopClosure back to summary

nopClosure	back to summary
public static <E> Closure<E> nopClosure() Gets a Closure that will do nothing. This could be useful during testing as a placeholder. Parameters <E> the type that the closure acts on Returns:Closure<E> the closure See Also `org.apache.commons.collections4.functors.NOPClosure`

public static <E> Closure<E> nopClosure()

Gets a Closure that will do nothing. This could be useful during testing as a placeholder.

Parameters

<E>: the type that the closure acts on

Returns:Closure<E>

the closure

switchClosure back to summary

switchClosure	back to summary
public static <E> Closure<E> switchClosure(final Predicate<? super E>[] predicates, final Closure<? super E>[] closures) Create a new Closure that calls one of the closures depending on the predicates. The closure at array location 0 is called if the predicate at array location 0 returned true. Each predicate is evaluated until one returns true. Parameters <E> the type that the closure acts on predicates:Predicate<? super E>[] an array of predicates to check, not null closures:Closure<? super E>[] an array of closures to call, not null Returns:Closure<E> the `switch` closure Exceptions NullPointerException: if the either array is null if any element in the arrays is null IllegalArgumentException: if the arrays have different sizes See Also `org.apache.commons.collections4.functors.SwitchClosure`

public static <E> Closure<E> switchClosure(final Predicate<? super E>[] predicates, final Closure<? super E>[] closures)

Create a new Closure that calls one of the closures depending on the predicates.

The closure at array location 0 is called if the predicate at array location 0 returned true. Each predicate is evaluated until one returns true.

Parameters

<E>: the type that the closure acts on
predicates:Predicate<? super E>[]: an array of predicates to check, not null
closures:Closure<? super E>[]: an array of closures to call, not null

Returns:Closure<E>

the switch closure

Exceptions

NullPointerException:

if the either array is null
if any element in the arrays is null

IllegalArgumentException:

if the arrays have different sizes

switchClosure back to summary

switchClosure	back to summary
public static <E> Closure<E> switchClosure(final Predicate<? super E>[] predicates, final Closure<? super E>[] closures, final Closure<? super E> defaultClosure) Create a new Closure that calls one of the closures depending on the predicates. The closure at array location 0 is called if the predicate at array location 0 returned true. Each predicate is evaluated until one returns true. If no predicates evaluate to true, the default closure is called. Parameters <E> the type that the closure acts on predicates:Predicate<? super E>[] an array of predicates to check, not null closures:Closure<? super E>[] an array of closures to call, not null defaultClosure:Closure<? super E> the default to call if no predicate matches Returns:Closure<E> the `switch` closure Exceptions NullPointerException: if the either array is null if any element in the arrays is null IllegalArgumentException: if the arrays are different sizes See Also `org.apache.commons.collections4.functors.SwitchClosure`

public static <E> Closure<E> switchClosure(final Predicate<? super E>[] predicates, final Closure<? super E>[] closures, final Closure<? super E> defaultClosure)

Create a new Closure that calls one of the closures depending on the predicates.

The closure at array location 0 is called if the predicate at array location 0 returned true. Each predicate is evaluated until one returns true. If no predicates evaluate to true, the default closure is called.

Parameters

<E>: the type that the closure acts on
predicates:Predicate<? super E>[]: an array of predicates to check, not null
closures:Closure<? super E>[]: an array of closures to call, not null
defaultClosure:Closure<? super E>: the default to call if no predicate matches

Returns:Closure<E>

the switch closure

Exceptions

NullPointerException:

if the either array is null
if any element in the arrays is null

IllegalArgumentException:

if the arrays are different sizes

switchClosure back to summary

switchClosure	back to summary
public static <E> Closure<E> switchClosure(final Map<Predicate<E>, Closure<E>> predicatesAndClosures) Create a new Closure that calls one of the closures depending on the predicates. The Map consists of Predicate keys and Closure values. A closure is called if its matching predicate returns true. Each predicate is evaluated until one returns true. If no predicates evaluate to true, the default closure is called. The default closure is set in the map with a null key. The ordering is that of the iterator() method on the entryset collection of the map. Parameters <E> the type that the closure acts on predicatesAndClosures:Map<Predicate<E>, Closure<E>> a map of predicates to closures Returns:Closure<E> the `switch` closure Exceptions NullPointerException: if the map is null if any closure in the map is null IllegalArgumentException: if the map is empty ClassCastException: if the map elements are of the wrong type See Also `org.apache.commons.collections4.functors.SwitchClosure`

public static <E> Closure<E> switchClosure(final Map<Predicate<E>, Closure<E>> predicatesAndClosures)

Create a new Closure that calls one of the closures depending on the predicates.

The Map consists of Predicate keys and Closure values. A closure is called if its matching predicate returns true. Each predicate is evaluated until one returns true. If no predicates evaluate to true, the default closure is called. The default closure is set in the map with a null key. The ordering is that of the iterator() method on the entryset collection of the map.

Parameters

<E>: the type that the closure acts on
predicatesAndClosures:Map<Predicate<E>, Closure<E>>: a map of predicates to closures

Returns:Closure<E>

the switch closure

Exceptions

NullPointerException:

if the map is null
if any closure in the map is null

IllegalArgumentException:

if the map is empty

ClassCastException:

if the map elements are of the wrong type

switchMapClosure back to summary

switchMapClosure	back to summary
public static <E> Closure<E> switchMapClosure(final Map<? extends E, Closure<E>> objectsAndClosures) Create a new Closure that uses the input object as a key to find the closure to call. The Map consists of object keys and Closure values. A closure is called if the input object equals the key. If there is no match, the default closure is called. The default closure is set in the map using a null key. Parameters <E> the type that the closure acts on objectsAndClosures:Map<? extends E, Closure<E>> a map of objects to closures Returns:Closure<E> the closure Annotations @SuppressWarnings:unchecked Exceptions NullPointerException: if the map is null if any closure in the map is null IllegalArgumentException: if the map is empty See Also `org.apache.commons.collections4.functors.SwitchClosure`

public static <E> Closure<E> switchMapClosure(final Map<? extends E, Closure<E>> objectsAndClosures)

Create a new Closure that uses the input object as a key to find the closure to call.

The Map consists of object keys and Closure values. A closure is called if the input object equals the key. If there is no match, the default closure is called. The default closure is set in the map using a null key.

Parameters

<E>: the type that the closure acts on
objectsAndClosures:Map<? extends E, Closure<E>>: a map of objects to closures

Returns:Closure<E>

the closure

Annotations

@SuppressWarnings:unchecked

Exceptions

NullPointerException:

if the map is null
if any closure in the map is null

IllegalArgumentException:

if the map is empty

whileClosure back to summary

whileClosure	back to summary
public static <E> Closure<E> whileClosure(final Predicate<? super E> predicate, final Closure<? super E> closure) Creates a Closure that will call the closure repeatedly until the predicate returns false. Parameters <E> the type that the closure acts on predicate:Predicate<? super E> the predicate to use as an end of loop test, not null closure:Closure<? super E> the closure to call repeatedly, not null Returns:Closure<E> the `while` closure Exceptions NullPointerException: if either argument is null See Also `org.apache.commons.collections4.functors.WhileClosure`

public static <E> Closure<E> whileClosure(final Predicate<? super E> predicate, final Closure<? super E> closure)

Creates a Closure that will call the closure repeatedly until the predicate returns false.

Parameters

<E>: the type that the closure acts on
predicate:Predicate<? super E>: the predicate to use as an end of loop test, not null
closure:Closure<? super E>: the closure to call repeatedly, not null

Returns:Closure<E>

the while closure

Exceptions

NullPointerException:: if either argument is null

public Class ClosureUtils

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Constructor Detail

Method Detail