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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      https://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.lang3.function;
19  
20  import java.io.IOException;
21  import java.io.UncheckedIOException;
22  import java.lang.reflect.UndeclaredThrowableException;
23  import java.util.Collection;
24  import java.util.Objects;
25  import java.util.Optional;
26  import java.util.concurrent.Callable;
27  import java.util.function.BiConsumer;
28  import java.util.function.BiFunction;
29  import java.util.function.BiPredicate;
30  import java.util.function.Consumer;
31  import java.util.function.Function;
32  import java.util.function.Predicate;
33  import java.util.function.Supplier;
34  import java.util.stream.Stream;
35  
36  import org.apache.commons.lang3.exception.ExceptionUtils;
37  import org.apache.commons.lang3.stream.Streams;
38  import org.apache.commons.lang3.stream.Streams.FailableStream;
39  
40  /**
41   * This class provides utility functions, and classes for working with the {@code java.util.function} package, or more
42   * generally, with Java 8 lambdas. More specifically, it attempts to address the fact that lambdas are supposed not to
43   * throw Exceptions, at least not checked Exceptions, like instances of {@link Exception}. This enforces the use of
44   * constructs like:
45   *
46   * <pre>{@code
47   * Consumer<java.lang.reflect.Method> consumer = m -> {
48   *     try {
49   *         m.invoke(o, args);
50   *     } catch (Throwable t) {
51   *         throw Failable.rethrow(t);
52   *     }
53   * };
54   * }
55   * </pre>
56   *
57   * <p>
58   * By replacing a {@link java.util.function.Consumer Consumer&lt;O&gt;} with a {@link FailableConsumer
59   * FailableConsumer&lt;O,? extends Throwable&gt;}, this can be written like follows:
60   * </p>
61   *
62   * <pre>{@code
63   * Functions.accept(m -> m.invoke(o, args));
64   * }</pre>
65   *
66   * <p>
67   * Obviously, the second version is much more concise and the spirit of Lambda expressions is met better than the second
68   * version.
69   * </p>
70   *
71   * @since 3.11
72   */
73  public class Failable {
74  
75      /**
76       * Consumes a consumer and rethrows any exception as a {@link RuntimeException}.
77       *
78       * @param consumer the consumer to accept, may be null for a noop.
79       * @param object1 the first object to consume by {@code consumer}
80       * @param object2 the second object to consume by {@code consumer}
81       * @param <T> the type of the first argument the consumer accepts
82       * @param <U> the type of the second argument the consumer accepts
83       * @param <E> the type of checked exception the consumer may throw
84       */
85      public static <T, U, E extends Throwable> void accept(final FailableBiConsumer<T, U, E> consumer, final T object1,
86          final U object2) {
87          run(consumer, () -> consumer.accept(object1, object2));
88      }
89  
90      /**
91       * Consumes a consumer and rethrows any exception as a {@link RuntimeException}.
92       *
93       * @param consumer the consumer to accept, may be null for a noop.
94       * @param object the object to consume by {@code consumer}
95       * @param <T> the type the consumer accepts
96       * @param <E> the type of checked exception the consumer may throw
97       */
98      public static <T, E extends Throwable> void accept(final FailableConsumer<T, E> consumer, final T object) {
99          run(consumer, () -> consumer.accept(object));
100     }
101 
102     /**
103      * Consumes a consumer and rethrows any exception as a {@link RuntimeException}.
104      *
105      * @param consumer the consumer to accept, may be null for a noop.
106      * @param value the value to consume by {@code consumer}
107      * @param <E> the type of checked exception the consumer may throw
108      */
109     public static <E extends Throwable> void accept(final FailableDoubleConsumer<E> consumer, final double value) {
110         run(consumer, () -> consumer.accept(value));
111     }
112 
113     /**
114      * Consumes a consumer and rethrows any exception as a {@link RuntimeException}.
115      *
116      * @param consumer the consumer to accept, may be null for a noop.
117      * @param value the value to consume by {@code consumer}
118      * @param <E> the type of checked exception the consumer may throw
119      */
120     public static <E extends Throwable> void accept(final FailableIntConsumer<E> consumer, final int value) {
121         run(consumer, () -> consumer.accept(value));
122     }
123 
124     /**
125      * Consumes a consumer and rethrows any exception as a {@link RuntimeException}.
126      *
127      * @param consumer the consumer to accept, may be null for a noop.
128      * @param value the value to consume by {@code consumer}
129      * @param <E> the type of checked exception the consumer may throw
130      */
131     public static <E extends Throwable> void accept(final FailableLongConsumer<E> consumer, final long value) {
132         run(consumer, () -> consumer.accept(value));
133     }
134 
135     /**
136      * Applies a function and rethrows any exception as a {@link RuntimeException}.
137      *
138      * @param function the function to apply
139      * @param input1 the first input to apply {@code function} on
140      * @param input2 the second input to apply {@code function} on
141      * @param <T> the type of the first argument the function accepts
142      * @param <U> the type of the second argument the function accepts
143      * @param <R> the return type of the function
144      * @param <E> the type of checked exception the function may throw
145      * @return the value returned from the function
146      */
147     public static <T, U, R, E extends Throwable> R apply(final FailableBiFunction<T, U, R, E> function, final T input1,
148         final U input2) {
149         return get(() -> function.apply(input1, input2));
150     }
151 
152     /**
153      * Applies a function and rethrows any exception as a {@link RuntimeException}.
154      *
155      * @param function the function to apply
156      * @param input the input to apply {@code function} on
157      * @param <T> the type of the argument the function accepts
158      * @param <R> the return type of the function
159      * @param <E> the type of checked exception the function may throw
160      * @return the value returned from the function
161      */
162     public static <T, R, E extends Throwable> R apply(final FailableFunction<T, R, E> function, final T input) {
163         return get(() -> function.apply(input));
164     }
165 
166     /**
167      * Applies a function and rethrows any exception as a {@link RuntimeException}.
168      *
169      * @param function the function to apply
170      * @param left the first input to apply {@code function} on
171      * @param right the second input to apply {@code function} on
172      * @param <E> the type of checked exception the function may throw
173      * @return the value returned from the function
174      */
175     public static <E extends Throwable> double applyAsDouble(final FailableDoubleBinaryOperator<E> function,
176         final double left, final double right) {
177         return getAsDouble(() -> function.applyAsDouble(left, right));
178     }
179 
180     /**
181      * Applies a value to a function if the value isn't {@code null}, otherwise the method returns {@code null}. If the value isn't {@code null} then return the
182      * result of the applying function.
183      *
184      * <pre>{@code
185      * Failable.applyNonNull("a", String::toUpperCase)  = "A"
186      * Failable.applyNonNull(null, String::toUpperCase) = null
187      * Failable.applyNonNull("a", s -> null)            = null
188      * }</pre>
189      * <p>
190      * Useful when working with expressions that may return {@code null} as it allows a single-line expression without using temporary local variables or
191      * evaluating expressions twice. Provides an alternative to using {@link Optional} that is shorter and has less allocation.
192      * </p>
193      *
194      * @param <T>    The type of the input of this method and the function.
195      * @param <R>    The type of the result of the function and this method.
196      * @param <E>    The type of thrown exception or error.
197      * @param value  The value to apply the function to, may be {@code null}.
198      * @param mapper The function to apply, must not be {@code null}.
199      * @return The result of the function (which may be {@code null}) or {@code null} if the input value is {@code null}.
200      * @throws E Thrown by the given function.
201      * @see #applyNonNull(Object, FailableFunction, FailableFunction)
202      * @see #applyNonNull(Object, FailableFunction, FailableFunction, FailableFunction)
203      * @since 3.19.0
204      */
205     public static <T, R, E extends Throwable> R applyNonNull(final T value, final FailableFunction<? super T, ? extends R, E> mapper) throws E {
206         return value != null ? Objects.requireNonNull(mapper, "mapper").apply(value) : null;
207     }
208 
209     /**
210      * Applies values to a chain of functions, where a {@code null} can short-circuit each step. A function is only applied if the previous value is not
211      * {@code null}, otherwise this method returns {@code null}.
212      *
213      * <pre>{@code
214      * Failable.applyNonNull(" a ", String::toUpperCase, String::trim) = "A"
215      * Failable.applyNonNull(null, String::toUpperCase, String::trim)  = null
216      * Failable.applyNonNull(" a ", s -> null, String::trim)           = null
217      * Failable.applyNonNull(" a ", String::toUpperCase, s -> null)    = null
218      * }</pre>
219      * <p>
220      * Useful when working with expressions that may return {@code null} as it allows a single-line expression without using temporary local variables or
221      * evaluating expressions twice. Provides an alternative to using {@link Optional} that is shorter and has less allocation.
222      * </p>
223      *
224      * @param <T>     The type of the input of this method and the first function.
225      * @param <U>     The type of the result of the first function and the input to the second function.
226      * @param <R>     The type of the result of the second function and this method.
227      * @param <E1>    The type of thrown exception or error by the first function.
228      * @param <E2>    The type of thrown exception or error by the second function.
229      * @param value1  The value to apply the functions to, may be {@code null}.
230      * @param mapper1 The first function to apply, must not be {@code null}.
231      * @param mapper2 The second function to apply, must not be {@code null}.
232      * @return The result of the final function (which may be {@code null}) or {@code null} if the input value or any intermediate value is {@code null}.
233      * @throws E1 Thrown by the first function.
234      * @throws E2 Thrown by the second function.
235      * @see #applyNonNull(Object, FailableFunction)
236      * @see #applyNonNull(Object, FailableFunction, FailableFunction, FailableFunction)
237      * @since 3.19.0
238      */
239     public static <T, U, R, E1 extends Throwable, E2 extends Throwable> R applyNonNull(final T value1,
240             final FailableFunction<? super T, ? extends U, E1> mapper1, final FailableFunction<? super U, ? extends R, E2> mapper2) throws E1, E2 {
241         return applyNonNull(applyNonNull(value1, mapper1), mapper2);
242     }
243 
244     /**
245      * Applies values to a chain of functions, where a {@code null} can short-circuit each step. A function is only applied if the previous value is not
246      * {@code null}, otherwise this method returns {@code null}.
247      *
248      * <pre>{@code
249      * Failable.applyNonNull(" abc ", String::toUpperCase, String::trim, StringUtils::reverse) = "CBA"
250      * Failable.applyNonNull(null, String::toUpperCase, String::trim, StringUtils::reverse)    = null
251      * Failable.applyNonNull(" abc ", s -> null, String::trim, StringUtils::reverse)           = null
252      * Failable.applyNonNull(" abc ", String::toUpperCase, s -> null, StringUtils::reverse)    = null
253      * Failable.applyNonNull(" abc ", String::toUpperCase, String::trim, s -> null)            = null
254      * }</pre>
255      * <p>
256      * Useful when working with expressions that may return {@code null} as it allows a single-line expression without using temporary local variables or
257      * evaluating expressions twice. Provides an alternative to using {@link Optional} that is shorter and has less allocation.
258      * </p>
259      *
260      * @param <T>     The type of the input of this method and the first function.
261      * @param <U>     The type of the result of the first function and the input to the second function.
262      * @param <V>     The type of the result of the second function and the input to the third function.
263      * @param <R>     The type of the result of the third function and this method.
264      * @param <E1>    The type of thrown exception or error by the first function.
265      * @param <E2>    The type of thrown exception or error by the second function.
266      * @param <E3>    The type of thrown exception or error by the second function.
267      * @param value1  The value to apply the first function, may be {@code null}.
268      * @param mapper1 The first function to apply, must not be {@code null}.
269      * @param mapper2 The second function to apply, must not be {@code null}.
270      * @param mapper3 The third function to apply, must not be {@code null}.
271      * @return The result of the final function (which may be {@code null}) or {@code null} if the input value or any intermediate value is {@code null}.
272      * @throws E1 Thrown by the first function.
273      * @throws E2 Thrown by the second function.
274      * @throws E3 Thrown by the third function.
275      * @see #applyNonNull(Object, FailableFunction)
276      * @see #applyNonNull(Object, FailableFunction, FailableFunction)
277      * @since 3.19.0
278      */
279     public static <T, U, V, R, E1 extends Throwable, E2 extends Throwable, E3 extends Throwable> R applyNonNull(final T value1,
280             final FailableFunction<? super T, ? extends U, E1> mapper1, final FailableFunction<? super U, ? extends V, E2> mapper2,
281             final FailableFunction<? super V, ? extends R, E3> mapper3) throws E1, E2, E3 {
282         return applyNonNull(applyNonNull(applyNonNull(value1, mapper1), mapper2), mapper3);
283     }
284 
285     /**
286      * Converts the given {@link FailableBiConsumer} into a standard {@link BiConsumer}.
287      *
288      * @param <T> the type of the first argument of the consumers
289      * @param <U> the type of the second argument of the consumers
290      * @param consumer a failable {@link BiConsumer}
291      * @return a standard {@link BiConsumer}
292      */
293     public static <T, U> BiConsumer<T, U> asBiConsumer(final FailableBiConsumer<T, U, ?> consumer) {
294         return (input1, input2) -> accept(consumer, input1, input2);
295     }
296 
297     /**
298      * Converts the given {@link FailableBiFunction} into a standard {@link BiFunction}.
299      *
300      * @param <T> the type of the first argument of the input of the functions
301      * @param <U> the type of the second argument of the input of the functions
302      * @param <R> the type of the output of the functions
303      * @param function a {@link FailableBiFunction}
304      * @return a standard {@link BiFunction}
305      */
306     public static <T, U, R> BiFunction<T, U, R> asBiFunction(final FailableBiFunction<T, U, R, ?> function) {
307         return (input1, input2) -> apply(function, input1, input2);
308     }
309 
310     /**
311      * Converts the given {@link FailableBiPredicate} into a standard {@link BiPredicate}.
312      *
313      * @param <T> the type of the first argument used by the predicates
314      * @param <U> the type of the second argument used by the predicates
315      * @param predicate a {@link FailableBiPredicate}
316      * @return a standard {@link BiPredicate}
317      */
318     public static <T, U> BiPredicate<T, U> asBiPredicate(final FailableBiPredicate<T, U, ?> predicate) {
319         return (input1, input2) -> test(predicate, input1, input2);
320     }
321 
322     /**
323      * Converts the given {@link FailableCallable} into a standard {@link Callable}.
324      *
325      * @param <V> the type used by the callables
326      * @param callable a {@link FailableCallable}
327      * @return a standard {@link Callable}
328      */
329     public static <V> Callable<V> asCallable(final FailableCallable<V, ?> callable) {
330         return () -> call(callable);
331     }
332 
333     /**
334      * Converts the given {@link FailableConsumer} into a standard {@link Consumer}.
335      *
336      * @param <T> the type used by the consumers
337      * @param consumer a {@link FailableConsumer}
338      * @return a standard {@link Consumer}
339      */
340     public static <T> Consumer<T> asConsumer(final FailableConsumer<T, ?> consumer) {
341         return input -> accept(consumer, input);
342     }
343 
344     /**
345      * Converts the given {@link FailableFunction} into a standard {@link Function}.
346      *
347      * @param <T> the type of the input of the functions
348      * @param <R> the type of the output of the functions
349      * @param function a {code FailableFunction}
350      * @return a standard {@link Function}
351      */
352     public static <T, R> Function<T, R> asFunction(final FailableFunction<T, R, ?> function) {
353         return input -> apply(function, input);
354     }
355 
356     /**
357      * Converts the given {@link FailablePredicate} into a standard {@link Predicate}.
358      *
359      * @param <T> the type used by the predicates
360      * @param predicate a {@link FailablePredicate}
361      * @return a standard {@link Predicate}
362      */
363     public static <T> Predicate<T> asPredicate(final FailablePredicate<T, ?> predicate) {
364         return input -> test(predicate, input);
365     }
366 
367     /**
368      * Converts the given {@link FailableRunnable} into a standard {@link Runnable}.
369      *
370      * @param runnable a {@link FailableRunnable}
371      * @return a standard {@link Runnable}
372      */
373     public static Runnable asRunnable(final FailableRunnable<?> runnable) {
374         return () -> run(runnable);
375     }
376 
377     /**
378      * Converts the given {@link FailableSupplier} into a standard {@link Supplier}.
379      *
380      * @param <T> the type supplied by the suppliers
381      * @param supplier a {@link FailableSupplier}
382      * @return a standard {@link Supplier}
383      */
384     public static <T> Supplier<T> asSupplier(final FailableSupplier<T, ?> supplier) {
385         return () -> get(supplier);
386     }
387 
388     /**
389      * Calls a callable and rethrows any exception as a {@link RuntimeException}.
390      *
391      * @param callable the callable to call
392      * @param <V> the return type of the callable
393      * @param <E> the type of checked exception the callable may throw
394      * @return the value returned from the callable
395      */
396     public static <V, E extends Throwable> V call(final FailableCallable<V, E> callable) {
397         return get(callable::call);
398     }
399 
400     /**
401      * Invokes a supplier, and returns the result.
402      *
403      * @param supplier The supplier to invoke.
404      * @param <T> The suppliers output type.
405      * @param <E> The type of checked exception, which the supplier can throw.
406      * @return The object, which has been created by the supplier
407      */
408     public static <T, E extends Throwable> T get(final FailableSupplier<T, E> supplier) {
409         try {
410             return supplier.get();
411         } catch (final Throwable t) {
412             throw rethrow(t);
413         }
414     }
415 
416     /**
417      * Invokes a boolean supplier, and returns the result.
418      *
419      * @param supplier The boolean supplier to invoke.
420      * @param <E> The type of checked exception, which the supplier can throw.
421      * @return The boolean, which has been created by the supplier
422      */
423     public static <E extends Throwable> boolean getAsBoolean(final FailableBooleanSupplier<E> supplier) {
424         try {
425             return supplier.getAsBoolean();
426         } catch (final Throwable t) {
427             throw rethrow(t);
428         }
429     }
430 
431     /**
432      * Invokes a double supplier, and returns the result.
433      *
434      * @param supplier The double supplier to invoke.
435      * @param <E> The type of checked exception, which the supplier can throw.
436      * @return The double, which has been created by the supplier
437      */
438     public static <E extends Throwable> double getAsDouble(final FailableDoubleSupplier<E> supplier) {
439         try {
440             return supplier.getAsDouble();
441         } catch (final Throwable t) {
442             throw rethrow(t);
443         }
444     }
445 
446     /**
447      * Invokes an int supplier, and returns the result.
448      *
449      * @param supplier The int supplier to invoke.
450      * @param <E> The type of checked exception, which the supplier can throw.
451      * @return The int, which has been created by the supplier
452      */
453     public static <E extends Throwable> int getAsInt(final FailableIntSupplier<E> supplier) {
454         try {
455             return supplier.getAsInt();
456         } catch (final Throwable t) {
457             throw rethrow(t);
458         }
459     }
460 
461     /**
462      * Invokes a long supplier, and returns the result.
463      *
464      * @param supplier The long supplier to invoke.
465      * @param <E> The type of checked exception, which the supplier can throw.
466      * @return The long, which has been created by the supplier
467      */
468     public static <E extends Throwable> long getAsLong(final FailableLongSupplier<E> supplier) {
469         try {
470             return supplier.getAsLong();
471         } catch (final Throwable t) {
472             throw rethrow(t);
473         }
474     }
475 
476     /**
477      * Invokes a short supplier, and returns the result.
478      *
479      * @param supplier The short supplier to invoke.
480      * @param <E> The type of checked exception, which the supplier can throw.
481      * @return The short, which has been created by the supplier
482      */
483     public static <E extends Throwable> short getAsShort(final FailableShortSupplier<E> supplier) {
484         try {
485             return supplier.getAsShort();
486         } catch (final Throwable t) {
487             throw rethrow(t);
488         }
489     }
490 
491     /**
492      * Rethrows a {@link Throwable} as an unchecked exception. If the argument is already unchecked, namely a
493      * {@link RuntimeException} or {@link Error} then the argument will be rethrown without modification. If the
494      * exception is {@link IOException} then it will be wrapped into a {@link UncheckedIOException}. In every other
495      * cases the exception will be wrapped into a {@code
496      * UndeclaredThrowableException}
497      *
498      * <p>
499      * Note that there is a declared return type for this method, even though it never returns. The reason for that is
500      * to support the usual pattern:
501      * </p>
502      *
503      * <pre>
504      * throw rethrow(myUncheckedException);
505      * </pre>
506      *
507      * <p>
508      * instead of just calling the method. This pattern may help the Java compiler to recognize that at that point an
509      * exception will be thrown and the code flow analysis will not demand otherwise mandatory commands that could
510      * follow the method call, like a {@code return} statement from a value returning method.
511      * </p>
512      *
513      * @param throwable The throwable to rethrow possibly wrapped into an unchecked exception
514      * @return Never returns anything, this method never terminates normally.
515      */
516     public static RuntimeException rethrow(final Throwable throwable) {
517         Objects.requireNonNull(throwable, "throwable");
518         ExceptionUtils.throwUnchecked(throwable);
519         if (throwable instanceof IOException) {
520             throw new UncheckedIOException((IOException) throwable);
521         }
522         throw new UndeclaredThrowableException(throwable);
523     }
524 
525     /**
526      * Runs a runnable and rethrows any exception as a {@link RuntimeException}.
527      *
528      * @param runnable The runnable to run, may be null for a noop.
529      * @param <E> the type of checked exception the runnable may throw.
530      */
531     public static <E extends Throwable> void run(final FailableRunnable<E> runnable) {
532         if (runnable != null) {
533             try {
534                 runnable.run();
535             } catch (final Throwable t) {
536                 throw rethrow(t);
537             }
538         }
539     }
540 
541     private static <E extends Throwable> void run(final Object test, final FailableRunnable<E> runnable) {
542         if (runnable != null && test != null) {
543             try {
544                 runnable.run();
545             } catch (final Throwable t) {
546                 throw rethrow(t);
547             }
548         }
549     }
550 
551     /**
552      * Converts the given collection into a {@link FailableStream}. The {@link FailableStream} consists of the
553      * collections elements. Shortcut for
554      *
555      * <pre>
556      * Functions.stream(collection.stream());
557      * </pre>
558      *
559      * @param collection The collection, which is being converted into a {@link FailableStream}.
560      * @param <E> The collections element type. (In turn, the result streams element type.)
561      * @return The created {@link FailableStream}.
562      */
563     public static <E> FailableStream<E> stream(final Collection<E> collection) {
564         return new FailableStream<>(collection.stream());
565     }
566 
567     /**
568      * Converts the given stream into a {@link FailableStream}. The {@link FailableStream} consists of the same
569      * elements, than the input stream. However, failable lambdas, like {@link FailablePredicate},
570      * {@link FailableFunction}, and {@link FailableConsumer} may be applied, rather than {@link Predicate},
571      * {@link Function}, {@link Consumer}, etc.
572      *
573      * @param stream The stream, which is being converted into a {@link FailableStream}.
574      * @param <T> The streams element type.
575      * @return The created {@link FailableStream}.
576      */
577     public static <T> FailableStream<T> stream(final Stream<T> stream) {
578         return new FailableStream<>(stream);
579     }
580 
581     /**
582      * Tests a predicate and rethrows any exception as a {@link RuntimeException}.
583      *
584      * @param predicate the predicate to test
585      * @param object1 the first input to test by {@code predicate}
586      * @param object2 the second input to test by {@code predicate}
587      * @param <T> the type of the first argument the predicate tests
588      * @param <U> the type of the second argument the predicate tests
589      * @param <E> the type of checked exception the predicate may throw
590      * @return the boolean value returned by the predicate
591      */
592     public static <T, U, E extends Throwable> boolean test(final FailableBiPredicate<T, U, E> predicate,
593         final T object1, final U object2) {
594         return getAsBoolean(() -> predicate.test(object1, object2));
595     }
596 
597     /**
598      * Tests a predicate and rethrows any exception as a {@link RuntimeException}.
599      *
600      * @param predicate the predicate to test
601      * @param object the input to test by {@code predicate}
602      * @param <T> the type of argument the predicate tests
603      * @param <E> the type of checked exception the predicate may throw
604      * @return the boolean value returned by the predicate
605      */
606     public static <T, E extends Throwable> boolean test(final FailablePredicate<T, E> predicate, final T object) {
607         return getAsBoolean(() -> predicate.test(object));
608     }
609 
610     /**
611      * A simple try-with-resources implementation, that can be used, if your objects do not implement the
612      * {@link AutoCloseable} interface. The method executes the {@code action}. The method guarantees, that <em>all</em>
613      * the {@code resources} are being executed, in the given order, afterwards, and regardless of success, or failure.
614      * If either the original action, or any of the resource action fails, then the <em>first</em> failure (AKA
615      * {@link Throwable}) is rethrown. Example use:
616      *
617      * <pre>{@code
618      * final FileInputStream fis = new FileInputStream("my.file");
619      * Functions.tryWithResources(useInputStream(fis), null, () -> fis.close());
620      * }</pre>
621      *
622      * @param action The action to execute. This object <em>will</em> always be invoked.
623      * @param errorHandler An optional error handler, which will be invoked finally, if any error occurred. The error
624      *        handler will receive the first error, AKA {@link Throwable}.
625      * @param resources The resource actions to execute. <em>All</em> resource actions will be invoked, in the given
626      *        order. A resource action is an instance of {@link FailableRunnable}, which will be executed.
627      * @see #tryWithResources(FailableRunnable, FailableRunnable...)
628      */
629     @SafeVarargs
630     public static void tryWithResources(final FailableRunnable<? extends Throwable> action,
631         final FailableConsumer<Throwable, ? extends Throwable> errorHandler,
632         final FailableRunnable<? extends Throwable>... resources) {
633         final FailableConsumer<Throwable, ? extends Throwable> actualErrorHandler;
634         if (errorHandler == null) {
635             actualErrorHandler = Failable::rethrow;
636         } else {
637             actualErrorHandler = errorHandler;
638         }
639         Streams.of(resources).forEach(r -> Objects.requireNonNull(r, "runnable"));
640         Throwable th = null;
641         try {
642             action.run();
643         } catch (final Throwable t) {
644             th = t;
645         }
646         if (resources != null) {
647             for (final FailableRunnable<?> runnable : resources) {
648                 try {
649                     runnable.run();
650                 } catch (final Throwable t) {
651                     if (th == null) {
652                         th = t;
653                     }
654                 }
655             }
656         }
657         if (th != null) {
658             try {
659                 actualErrorHandler.accept(th);
660             } catch (final Throwable t) {
661                 throw rethrow(t);
662             }
663         }
664     }
665 
666     /**
667      * A simple try-with-resources implementation, that can be used, if your objects do not implement the
668      * {@link AutoCloseable} interface. The method executes the {@code action}. The method guarantees, that <em>all</em>
669      * the {@code resources} are being executed, in the given order, afterwards, and regardless of success, or failure.
670      * If either the original action, or any of the resource action fails, then the <em>first</em> failure (AKA
671      * {@link Throwable}) is rethrown. Example use:
672      *
673      * <pre>{@code
674      * final FileInputStream fis = new FileInputStream("my.file");
675      * Functions.tryWithResources(useInputStream(fis), () -> fis.close());
676      * }</pre>
677      *
678      * @param action The action to execute. This object <em>will</em> always be invoked.
679      * @param resources The resource actions to execute. <em>All</em> resource actions will be invoked, in the given
680      *        order. A resource action is an instance of {@link FailableRunnable}, which will be executed.
681      * @see #tryWithResources(FailableRunnable, FailableConsumer, FailableRunnable...)
682      */
683     @SafeVarargs
684     public static void tryWithResources(final FailableRunnable<? extends Throwable> action, final FailableRunnable<? extends Throwable>... resources) {
685         tryWithResources(action, null, resources);
686     }
687 
688     private Failable() {
689         // empty
690     }
691 
692 }