org.apache.commons.lang3

Class Functions

java.lang.Object

org.apache.commons.lang3.Functions

Deprecated.

Use Failable.

@Deprecated
public class Functions
extends java.lang.Object

This class provides utility functions, and classes for working with the java.util.function package, or more generally, with Java 8 lambdas. More specifically, it attempts to address the fact that lambdas are supposed not to throw Exceptions, at least not checked Exceptions, AKA instances of Exception. This enforces the use of constructs like:

 
     Consumer<java.lang.reflect.Method> consumer = m -> {
         try {
             m.invoke(o, args);
         } catch (Throwable t) {
             throw Functions.rethrow(t);
         }
     };
 

By replacing a Consumer<O> with a FailableConsumer<O,? extends Throwable>, this can be written like follows:

 
   Functions.accept((m) -> m.invoke(o,args));
 

Obviously, the second version is much more concise and the spirit of Lambda expressions is met better than the second version.

Since:

3.9

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Functions.FailableBiConsumer<O1,O2,T extends java.lang.Throwable> Deprecated. Use FailableBiConsumer.
static interface	Functions.FailableBiFunction<O1,O2,R,T extends java.lang.Throwable> Deprecated. Use FailableBiFunction.
static interface	Functions.FailableBiPredicate<O1,O2,T extends java.lang.Throwable> Deprecated. Use FailableBiPredicate.
static interface	Functions.FailableCallable<R,T extends java.lang.Throwable> Deprecated. Use FailableCallable.
static interface	Functions.FailableConsumer<O,T extends java.lang.Throwable> Deprecated. Use FailableConsumer.
static interface	Functions.FailableFunction<I,R,T extends java.lang.Throwable> Deprecated. Use FailableFunction.
static interface	Functions.FailablePredicate<I,T extends java.lang.Throwable> Deprecated. Use FailablePredicate.
static interface	Functions.FailableRunnable<T extends java.lang.Throwable> Deprecated. Use FailableRunnable.
static interface	Functions.FailableSupplier<R,T extends java.lang.Throwable> Deprecated. Use FailableSupplier.

Constructor Summary

Constructors

Constructor and Description
Functions() Deprecated.

Method Summary

Modifier and Type	Method and Description
static <O1,O2,T extends java.lang.Throwable> void	accept(Functions.FailableBiConsumer<O1,O2,T> consumer, O1 object1, O2 object2) Deprecated. Consumes a consumer and rethrows any exception as a RuntimeException.
static <O,T extends java.lang.Throwable> void	accept(Functions.FailableConsumer<O,T> consumer, O object) Deprecated. Consumes a consumer and rethrows any exception as a RuntimeException.
static <O1,O2,O,T extends java.lang.Throwable> O	apply(Functions.FailableBiFunction<O1,O2,O,T> function, O1 input1, O2 input2) Deprecated. Applies a function and rethrows any exception as a RuntimeException.
static <I,O,T extends java.lang.Throwable> O	apply(Functions.FailableFunction<I,O,T> function, I input) Deprecated. Applies a function and rethrows any exception as a RuntimeException.
static <O1,O2> java.util.function.BiConsumer<O1,O2>	asBiConsumer(Functions.FailableBiConsumer<O1,O2,?> consumer) Deprecated. Converts the given Functions.FailableBiConsumer into a standard BiConsumer.
static <O1,O2,O> java.util.function.BiFunction<O1,O2,O>	asBiFunction(Functions.FailableBiFunction<O1,O2,O,?> function) Deprecated. Converts the given Functions.FailableBiFunction into a standard BiFunction.
static <O1,O2> java.util.function.BiPredicate<O1,O2>	asBiPredicate(Functions.FailableBiPredicate<O1,O2,?> predicate) Deprecated. Converts the given Functions.FailableBiPredicate into a standard BiPredicate.
static <O> java.util.concurrent.Callable<O>	asCallable(Functions.FailableCallable<O,?> callable) Deprecated. Converts the given Functions.FailableCallable into a standard Callable.
static <I> java.util.function.Consumer<I>	asConsumer(Functions.FailableConsumer<I,?> consumer) Deprecated. Converts the given Functions.FailableConsumer into a standard Consumer.
static <I,O> java.util.function.Function<I,O>	asFunction(Functions.FailableFunction<I,O,?> function) Deprecated. Converts the given Functions.FailableFunction into a standard Function.
static <I> java.util.function.Predicate<I>	asPredicate(Functions.FailablePredicate<I,?> predicate) Deprecated. Converts the given Functions.FailablePredicate into a standard Predicate.
static java.lang.Runnable	asRunnable(Functions.FailableRunnable<?> runnable) Deprecated. Converts the given Functions.FailableRunnable into a standard Runnable.
static <O> java.util.function.Supplier<O>	asSupplier(Functions.FailableSupplier<O,?> supplier) Deprecated. Converts the given Functions.FailableSupplier into a standard Supplier.
static <O,T extends java.lang.Throwable> O	call(Functions.FailableCallable<O,T> callable) Deprecated. Calls a callable and rethrows any exception as a RuntimeException.
static <O,T extends java.lang.Throwable> O	get(Functions.FailableSupplier<O,T> supplier) Deprecated. Invokes a supplier, and returns the result.
static java.lang.RuntimeException	rethrow(java.lang.Throwable throwable) Deprecated. Rethrows a Throwable as an unchecked exception.
static <T extends java.lang.Throwable> void	run(Functions.FailableRunnable<T> runnable) Deprecated. Runs a runnable and rethrows any exception as a RuntimeException.
static <O> Streams.FailableStream<O>	stream(java.util.Collection<O> collection) Deprecated. Converts the given collection into a Streams.FailableStream.
static <O> Streams.FailableStream<O>	stream(java.util.stream.Stream<O> stream) Deprecated. Converts the given stream into a Streams.FailableStream.
static <O1,O2,T extends java.lang.Throwable> boolean	test(Functions.FailableBiPredicate<O1,O2,T> predicate, O1 object1, O2 object2) Deprecated. Tests a predicate and rethrows any exception as a RuntimeException.
static <O,T extends java.lang.Throwable> boolean	test(Functions.FailablePredicate<O,T> predicate, O object) Deprecated. Tests a predicate and rethrows any exception as a RuntimeException.
static void	tryWithResources(Functions.FailableRunnable<? extends java.lang.Throwable> action, Functions.FailableConsumer<java.lang.Throwable,? extends java.lang.Throwable> errorHandler, Functions.FailableRunnable<? extends java.lang.Throwable>... resources) Deprecated. A simple try-with-resources implementation, that can be used, if your objects do not implement the AutoCloseable interface.
static void	tryWithResources(Functions.FailableRunnable<? extends java.lang.Throwable> action, Functions.FailableRunnable<? extends java.lang.Throwable>... resources) Deprecated. A simple try-with-resources implementation, that can be used, if your objects do not implement the AutoCloseable interface.

Methods inherited from class java.lang.Object

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

Constructor Detail

Functions

public Functions()

Deprecated.

Method Detail

accept

public static <O1,O2,T extends java.lang.Throwable> void accept(Functions.FailableBiConsumer<O1,O2,T> consumer,
                                                                O1 object1,
                                                                O2 object2)

Deprecated.

Consumes a consumer and rethrows any exception as a RuntimeException.

Type Parameters:

O1 - the type of the first argument the consumer accepts

O2 - the type of the second argument the consumer accepts

T - the type of checked exception the consumer may throw

Parameters:

consumer - the consumer to consume

object1 - the first object to consume by consumer

object2 - the second object to consume by consumer

accept

public static <O,T extends java.lang.Throwable> void accept(Functions.FailableConsumer<O,T> consumer,
                                                            O object)

Deprecated.

Consumes a consumer and rethrows any exception as a RuntimeException.

Type Parameters:

O - the type the consumer accepts

T - the type of checked exception the consumer may throw

Parameters:

consumer - the consumer to consume

object - the object to consume by consumer

apply

public static <O1,O2,O,T extends java.lang.Throwable> O apply(Functions.FailableBiFunction<O1,O2,O,T> function,
                                                              O1 input1,
                                                              O2 input2)

Deprecated.

Applies a function and rethrows any exception as a RuntimeException.

Type Parameters:

O1 - the type of the first argument the function accepts

O2 - the type of the second argument the function accepts

O - the return type of the function

T - the type of checked exception the function may throw

Parameters:

function - the function to apply

input1 - the first input to apply function on

input2 - the second input to apply function on

Returns:

the value returned from the function

apply

public static <I,O,T extends java.lang.Throwable> O apply(Functions.FailableFunction<I,O,T> function,
                                                          I input)

Deprecated.

Applies a function and rethrows any exception as a RuntimeException.

Type Parameters:

I - the type of the argument the function accepts

O - the return type of the function

T - the type of checked exception the function may throw

Parameters:

function - the function to apply

input - the input to apply function on

Returns:

the value returned from the function

asBiConsumer

public static <O1,O2> java.util.function.BiConsumer<O1,O2> asBiConsumer(Functions.FailableBiConsumer<O1,O2,?> consumer)

Deprecated.

Converts the given Functions.FailableBiConsumer into a standard BiConsumer.

Type Parameters:

O1 - the type of the first argument of the consumers

O2 - the type of the second argument of the consumers

Parameters:

consumer - a failable BiConsumer

Returns:

a standard BiConsumer

Since:

3.10

asBiFunction

public static <O1,O2,O> java.util.function.BiFunction<O1,O2,O> asBiFunction(Functions.FailableBiFunction<O1,O2,O,?> function)

Deprecated.

Converts the given Functions.FailableBiFunction into a standard BiFunction.

Type Parameters:

O1 - the type of the first argument of the input of the functions

O2 - the type of the second argument of the input of the functions

O - the type of the output of the functions

Parameters:

function - a Functions.FailableBiFunction

Returns:

a standard BiFunction

Since:

3.10

asBiPredicate

public static <O1,O2> java.util.function.BiPredicate<O1,O2> asBiPredicate(Functions.FailableBiPredicate<O1,O2,?> predicate)

Deprecated.

Converts the given Functions.FailableBiPredicate into a standard BiPredicate.

Type Parameters:

O1 - the type of the first argument used by the predicates

O2 - the type of the second argument used by the predicates

Parameters:

predicate - a Functions.FailableBiPredicate

Returns:

a standard BiPredicate

Since:

3.10

asCallable

public static <O> java.util.concurrent.Callable<O> asCallable(Functions.FailableCallable<O,?> callable)

Deprecated.

Converts the given Functions.FailableCallable into a standard Callable.

Type Parameters:

O - the type used by the callables

Parameters:

callable - a Functions.FailableCallable

Returns:

a standard Callable

Since:

3.10

asConsumer

public static <I> java.util.function.Consumer<I> asConsumer(Functions.FailableConsumer<I,?> consumer)

Deprecated.

Converts the given Functions.FailableConsumer into a standard Consumer.

Type Parameters:

I - the type used by the consumers

Parameters:

consumer - a Functions.FailableConsumer

Returns:

a standard Consumer

Since:

3.10

asFunction

public static <I,O> java.util.function.Function<I,O> asFunction(Functions.FailableFunction<I,O,?> function)

Deprecated.

Converts the given Functions.FailableFunction into a standard Function.

Type Parameters:

I - the type of the input of the functions

O - the type of the output of the functions

Parameters:

function - a {code FailableFunction}

Returns:

a standard Function

Since:

3.10

asPredicate

public static <I> java.util.function.Predicate<I> asPredicate(Functions.FailablePredicate<I,?> predicate)

Deprecated.

Converts the given Functions.FailablePredicate into a standard Predicate.

Type Parameters:

I - the type used by the predicates

Parameters:

predicate - a Functions.FailablePredicate

Returns:

a standard Predicate

Since:

3.10

asRunnable

public static java.lang.Runnable asRunnable(Functions.FailableRunnable<?> runnable)

Deprecated.

Converts the given Functions.FailableRunnable into a standard Runnable.

Parameters:

runnable - a Functions.FailableRunnable

Returns:

a standard Runnable

Since:

3.10

asSupplier

public static <O> java.util.function.Supplier<O> asSupplier(Functions.FailableSupplier<O,?> supplier)

Deprecated.

Converts the given Functions.FailableSupplier into a standard Supplier.

Type Parameters:

O - the type supplied by the suppliers

Parameters:

supplier - a Functions.FailableSupplier

Returns:

a standard Supplier

Since:

3.10

call

public static <O,T extends java.lang.Throwable> O call(Functions.FailableCallable<O,T> callable)

Deprecated.

Calls a callable and rethrows any exception as a RuntimeException.

Type Parameters:

O - the return type of the callable

T - the type of checked exception the callable may throw

Parameters:

callable - the callable to call

Returns:

the value returned from the callable

get

public static <O,T extends java.lang.Throwable> O get(Functions.FailableSupplier<O,T> supplier)

Deprecated.

Invokes a supplier, and returns the result.

Type Parameters:

O - The suppliers output type.

T - The type of checked exception, which the supplier can throw.

Parameters:

supplier - The supplier to invoke.

Returns:

The object, which has been created by the supplier

Since:

3.10

rethrow

public static java.lang.RuntimeException rethrow(java.lang.Throwable throwable)

Deprecated.

Rethrows a Throwable as an unchecked exception. If the argument is already unchecked, namely a RuntimeException or Error then the argument will be rethrown without modification. If the exception is IOException then it will be wrapped into a UncheckedIOException. In every other cases the exception will be wrapped into a UndeclaredThrowableException

Note that there is a declared return type for this method, even though it never returns. The reason for that is to support the usual pattern:

 throw rethrow(myUncheckedException);

instead of just calling the method. This pattern may help the Java compiler to recognize that at that point an exception will be thrown and the code flow analysis will not demand otherwise mandatory commands that could follow the method call, like a return statement from a value returning method.

Parameters:

throwable - The throwable to rethrow possibly wrapped into an unchecked exception

Returns:

Never returns anything, this method never terminates normally.

run

public static <T extends java.lang.Throwable> void run(Functions.FailableRunnable<T> runnable)

Deprecated.

Runs a runnable and rethrows any exception as a RuntimeException.

Type Parameters:

T - the type of checked exception the runnable may throw

Parameters:

runnable - The runnable to run

stream

public static <O> Streams.FailableStream<O> stream(java.util.Collection<O> collection)

Deprecated.

Converts the given collection into a Streams.FailableStream. The Streams.FailableStream consists of the collections elements. Shortcut for

 Functions.stream(collection.stream());

Type Parameters:

O - The collections element type. (In turn, the result streams element type.)

Parameters:

collection - The collection, which is being converted into a Streams.FailableStream.

Returns:

The created Streams.FailableStream.

Since:

3.10

stream

public static <O> Streams.FailableStream<O> stream(java.util.stream.Stream<O> stream)

Deprecated.

Converts the given stream into a Streams.FailableStream. The Streams.FailableStream consists of the same elements, than the input stream. However, failable lambdas, like Functions.FailablePredicate, Functions.FailableFunction, and Functions.FailableConsumer may be applied, rather than Predicate, Function, Consumer, etc.

Type Parameters:

O - The streams element type.

Parameters:

stream - The stream, which is being converted into a Streams.FailableStream.

Returns:

The created Streams.FailableStream.

Since:

3.10

test

public static <O1,O2,T extends java.lang.Throwable> boolean test(Functions.FailableBiPredicate<O1,O2,T> predicate,
                                                                 O1 object1,
                                                                 O2 object2)

Deprecated.

Tests a predicate and rethrows any exception as a RuntimeException.

Type Parameters:

O1 - the type of the first argument the predicate tests

O2 - the type of the second argument the predicate tests

T - the type of checked exception the predicate may throw

Parameters:

predicate - the predicate to test

object1 - the first input to test by predicate

object2 - the second input to test by predicate

Returns:

the boolean value returned by the predicate

test

public static <O,T extends java.lang.Throwable> boolean test(Functions.FailablePredicate<O,T> predicate,
                                                             O object)

Deprecated.

Tests a predicate and rethrows any exception as a RuntimeException.

Type Parameters:

O - the type of argument the predicate tests

T - the type of checked exception the predicate may throw

Parameters:

predicate - the predicate to test

object - the input to test by predicate

Returns:

the boolean value returned by the predicate

tryWithResources

@SafeVarargs
public static void tryWithResources(Functions.FailableRunnable<? extends java.lang.Throwable> action,
                                                 Functions.FailableConsumer<java.lang.Throwable,? extends java.lang.Throwable> errorHandler,
                                                 Functions.FailableRunnable<? extends java.lang.Throwable>... resources)

Deprecated.

A simple try-with-resources implementation, that can be used, if your objects do not implement the AutoCloseable interface. The method executes the action. The method guarantees, that all the resources are being executed, in the given order, afterwards, and regardless of success, or failure. If either the original action, or any of the resource action fails, then the first failure (AKA Throwable) is rethrown. Example use:

 
     final FileInputStream fis = new FileInputStream("my.file");
     Functions.tryWithResources(useInputStream(fis), null, () -> fis.close());
 

Parameters:

action - The action to execute. This object will always be invoked.

errorHandler - An optional error handler, which will be invoked finally, if any error occurred. The error handler will receive the first error, AKA Throwable.

resources - The resource actions to execute. All resource actions will be invoked, in the given order. A resource action is an instance of Functions.FailableRunnable, which will be executed.

See Also:

tryWithResources(FailableRunnable, FailableRunnable...)

tryWithResources

@SafeVarargs
public static void tryWithResources(Functions.FailableRunnable<? extends java.lang.Throwable> action,
                                                 Functions.FailableRunnable<? extends java.lang.Throwable>... resources)

Deprecated.

A simple try-with-resources implementation, that can be used, if your objects do not implement the AutoCloseable interface. The method executes the action. The method guarantees, that all the resources are being executed, in the given order, afterwards, and regardless of success, or failure. If either the original action, or any of the resource action fails, then the first failure (AKA Throwable) is rethrown. Example use:

 
     final FileInputStream fis = new FileInputStream("my.file");
     Functions.tryWithResources(useInputStream(fis), () -> fis.close());
 

Parameters:

action - The action to execute. This object will always be invoked.

resources - The resource actions to execute. All resource actions will be invoked, in the given order. A resource action is an instance of Functions.FailableRunnable, which will be executed.

See Also:

tryWithResources(FailableRunnable, FailableConsumer, FailableRunnable...)