You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@commons.apache.org by jo...@apache.org on 2020/02/07 20:59:41 UTC

[commons-lang] branch master updated: Fixing Checkstyle problems.

This is an automated email from the ASF dual-hosted git repository.

jochen pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-lang.git


The following commit(s) were added to refs/heads/master by this push:
     new 3ce3b27  Fixing Checkstyle problems.
3ce3b27 is described below

commit 3ce3b27dbd579a918e97e1fb09e9b0153cc71a60
Author: Jochen Wiedmann <jo...@gmail.com>
AuthorDate: Fri Feb 7 21:59:23 2020 +0100

    Fixing Checkstyle problems.
---
 .../java/org/apache/commons/lang3/Streams.java     | 631 +++++++++++----------
 .../java/org/apache/commons/lang3/StreamsTest.java |  12 +-
 2 files changed, 345 insertions(+), 298 deletions(-)

diff --git a/src/main/java/org/apache/commons/lang3/Streams.java b/src/main/java/org/apache/commons/lang3/Streams.java
index a0f32af..c097d76 100644
--- a/src/main/java/org/apache/commons/lang3/Streams.java
+++ b/src/main/java/org/apache/commons/lang3/Streams.java
@@ -16,6 +16,7 @@
  */
 package org.apache.commons.lang3;
 
+import java.util.Collection;
 import java.util.function.BiConsumer;
 import java.util.function.BinaryOperator;
 import java.util.function.Consumer;
@@ -48,7 +49,7 @@ import org.apache.commons.lang3.Functions.FailablePredicate;
  * </pre>
  * Using a {@link FailableStream}, this can be rewritten as follows:
  * <pre>
- *     ObjectStreams.failable(stream).forEach((m) -&gt; m.invoke(o, args));
+ *     Streams.failable(stream).forEach((m) -&gt; m.invoke(o, args));
  * </pre>
  * Obviously, the second version is much more concise and the spirit of
  * Lambda expressions is met better than in the first version.
@@ -56,309 +57,351 @@ import org.apache.commons.lang3.Functions.FailablePredicate;
  * @see Functions
  */
 public class Streams {
-	/** A reduced, and simplified version of a {@link Stream} with
-	 * failable method signatures.
-	 * @param <O> The streams element type.
-	 */
-	public static class FailableStream<O extends Object> {
-		private Stream<O> stream;
-		private boolean terminated;
+   /** A reduced, and simplified version of a {@link Stream} with
+     * failable method signatures.
+     * @param <O> The streams element type.
+     */
+    public static class FailableStream<O extends Object> {
+        private Stream<O> stream;
+        private boolean terminated;
 
-		public FailableStream(Stream<O> pStream) {
-			stream = pStream;
-		}
+        public FailableStream(Stream<O> pStream) {
+            stream = pStream;
+        }
 
-		protected void assertNotTerminated() {
-		    if (terminated) {
-		        throw new IllegalStateException("This stream is already terminated.");
-		    }
-		}
+        protected void assertNotTerminated() {
+            if (terminated) {
+                throw new IllegalStateException("This stream is already terminated.");
+            }
+        }
 
-		protected void makeTerminated() {
-		    assertNotTerminated();
-		    terminated = true;
-		}
+        protected void makeTerminated() {
+            assertNotTerminated();
+            terminated = true;
+        }
 
-		/**
-	     * Returns a FailableStream consisting of the elements of this stream that match
-	     * the given FailablePredicate.
-	     *
-	     * <p>This is an intermediate operation.
-	     *
-	     * @param pPredicate a non-interfering, stateless predicate to apply to each
-	     * element to determine if it should be included.
-	     * @return the new stream
-	     */
-		public FailableStream<O> filter(FailablePredicate<O,?> pPredicate){
-		    assertNotTerminated();
-			stream = stream.filter(Functions.asPredicate(pPredicate));
-			return this;
-		}
+        /**
+         * Returns a FailableStream consisting of the elements of this stream that match
+         * the given FailablePredicate.
+         *
+         * <p>This is an intermediate operation.
+         *
+         * @param pPredicate a non-interfering, stateless predicate to apply to each
+         * element to determine if it should be included.
+         * @return the new stream
+         */
+        public FailableStream<O> filter(FailablePredicate<O, ?> pPredicate){
+            assertNotTerminated();
+            stream = stream.filter(Functions.asPredicate(pPredicate));
+            return this;
+        }
 
-	    /**
-	     * Performs an action for each element of this stream.
-	     *
-	     * <p>This is a terminal operation.
-	     *
-	     * <p>The behavior of this operation is explicitly nondeterministic.
-	     * For parallel stream pipelines, this operation does <em>not</em>
-	     * guarantee to respect the encounter order of the stream, as doing so
-	     * would sacrifice the benefit of parallelism.  For any given element, the
-	     * action may be performed at whatever time and in whatever thread the
-	     * library chooses.  If the action accesses shared state, it is
-	     * responsible for providing the required synchronization.
-	     *
-	     * @param pAction a non-interfering action to perform on the elements
-	     */
-		public void forEach(FailableConsumer<O,?> pAction) {
-		    makeTerminated();
-		    stream().forEach(Functions.asConsumer(pAction));
-		}
+        /**
+         * Performs an action for each element of this stream.
+         *
+         * <p>This is a terminal operation.
+         *
+         * <p>The behavior of this operation is explicitly nondeterministic.
+         * For parallel stream pipelines, this operation does <em>not</em>
+         * guarantee to respect the encounter order of the stream, as doing so
+         * would sacrifice the benefit of parallelism.  For any given element, the
+         * action may be performed at whatever time and in whatever thread the
+         * library chooses.  If the action accesses shared state, it is
+         * responsible for providing the required synchronization.
+         *
+         * @param pAction a non-interfering action to perform on the elements
+         */
+        public void forEach(FailableConsumer<O, ?> pAction) {
+            makeTerminated();
+            stream().forEach(Functions.asConsumer(pAction));
+        }
 
-	    /**
-	     * Performs a mutable reduction operation on the elements of this stream using a
-	     * {@code Collector}.  A {@code Collector}
-	     * encapsulates the functions used as arguments to
-	     * {@link #collect(Supplier, BiConsumer, BiConsumer)}, allowing for reuse of
-	     * collection strategies and composition of collect operations such as
-	     * multiple-level grouping or partitioning.
-	     *
-	     * <p>If the underlying stream is parallel, and the {@code Collector}
-	     * is concurrent, and either the stream is unordered or the collector is
-	     * unordered, then a concurrent reduction will be performed
-	     * (see {@link Collector} for details on concurrent reduction.)
-	     *
-	     * <p>This is a terminal operation.
-	     *
-	     * <p>When executed in parallel, multiple intermediate results may be
-	     * instantiated, populated, and merged so as to maintain isolation of
-	     * mutable data structures.  Therefore, even when executed in parallel
-	     * with non-thread-safe data structures (such as {@code ArrayList}), no
-	     * additional synchronization is needed for a parallel reduction.
-	     *
-	     * \@apiNote
-	     * The following will accumulate strings into an ArrayList:
-	     * <pre>{@code
-	     *     List<String> asList = stringStream.collect(Collectors.toList());
-	     * }</pre>
-	     *
-	     * <p>The following will classify {@code Person} objects by city:
-	     * <pre>{@code
-	     *     Map<String, List<Person>> peopleByCity
-	     *         = personStream.collect(Collectors.groupingBy(Person::getCity));
-	     * }</pre>
-	     *
-	     * <p>The following will classify {@code Person} objects by state and city,
-	     * cascading two {@code Collector}s together:
-	     * <pre>{@code
-	     *     Map<String, Map<String, List<Person>>> peopleByStateAndCity
-	     *         = personStream.collect(Collectors.groupingBy(Person::getState,
-	     *                                                      Collectors.groupingBy(Person::getCity)));
-	     * }</pre>
-	     *
-	     * @param <R> the type of the result
-	     * @param <A> the intermediate accumulation type of the {@code Collector}
-	     * @param pCollector the {@code Collector} describing the reduction
-	     * @return the result of the reduction
-	     * @see #collect(Supplier, BiConsumer, BiConsumer)
-	     * @see Collectors
-	     */
-		public <A,R> R collect(Collector<? super O,A,R> pCollector) {
+        /**
+         * Performs a mutable reduction operation on the elements of this stream using a
+         * {@code Collector}.  A {@code Collector}
+         * encapsulates the functions used as arguments to
+         * {@link #collect(Supplier, BiConsumer, BiConsumer)}, allowing for reuse of
+         * collection strategies and composition of collect operations such as
+         * multiple-level grouping or partitioning.
+         *
+         * <p>If the underlying stream is parallel, and the {@code Collector}
+         * is concurrent, and either the stream is unordered or the collector is
+         * unordered, then a concurrent reduction will be performed
+         * (see {@link Collector} for details on concurrent reduction.)
+         *
+         * <p>This is a terminal operation.
+         *
+         * <p>When executed in parallel, multiple intermediate results may be
+         * instantiated, populated, and merged so as to maintain isolation of
+         * mutable data structures.  Therefore, even when executed in parallel
+         * with non-thread-safe data structures (such as {@code ArrayList}), no
+         * additional synchronization is needed for a parallel reduction.
+         *
+         * \@apiNote
+         * The following will accumulate strings into an ArrayList:
+         * <pre>{@code
+         *     List<String> asList = stringStream.collect(Collectors.toList());
+         * }</pre>
+         *
+         * <p>The following will classify {@code Person} objects by city:
+         * <pre>{@code
+         *     Map<String, List<Person>> peopleByCity
+         *         = personStream.collect(Collectors.groupingBy(Person::getCity));
+         * }</pre>
+         *
+         * <p>The following will classify {@code Person} objects by state and city,
+         * cascading two {@code Collector}s together:
+         * <pre>{@code
+         *     Map<String, Map<String, List<Person>>> peopleByStateAndCity
+         *         = personStream.collect(Collectors.groupingBy(Person::getState,
+         *                                                      Collectors.groupingBy(Person::getCity)));
+         * }</pre>
+         *
+         * @param <R> the type of the result
+         * @param <A> the intermediate accumulation type of the {@code Collector}
+         * @param pCollector the {@code Collector} describing the reduction
+         * @return the result of the reduction
+         * @see #collect(Supplier, BiConsumer, BiConsumer)
+         * @see Collectors
+         */
+        public <A, R> R collect(Collector<? super O, A, R> pCollector) {
             makeTerminated();
-			return stream().collect(pCollector);
-		}
+            return stream().collect(pCollector);
+        }
 
-	    /**
-	     * Performs a mutable reduction operation on the elements of this FailableStream.
-	     * A mutable reduction is one in which the reduced value is a mutable result
-	     * container, such as an {@code ArrayList}, and elements are incorporated by updating
-	     * the state of the result rather than by replacing the result. This produces a result equivalent to:
-	     * <pre>{@code
-	     *     R result = supplier.get();
-	     *     for (T element : this stream)
-	     *         accumulator.accept(result, element);
-	     *     return result;
-	     * }</pre>
-	     *
-	     * <p>Like {@link #reduce(Object, BinaryOperator)}, {@code collect} operations
-	     * can be parallelized without requiring additional synchronization.
-	     *
-	     * <p>This is a terminal operation.
-	     *
-	     * \@apiNote There are many existing classes in the JDK whose signatures are
-	     * well-suited for use with method references as arguments to {@code collect()}.
-	     * For example, the following will accumulate strings into an {@code ArrayList}:
-	     * <pre>{@code
-	     *     List<String> asList = stringStream.collect(ArrayList::new, ArrayList::add,
-	     *                                                ArrayList::addAll);
-	     * }</pre>
-	     *
-	     * <p>The following will take a stream of strings and concatenates them into a
-	     * single string:
-	     * <pre>{@code
-	     *     String concat = stringStream.collect(StringBuilder::new, StringBuilder::append,
-	     *                                          StringBuilder::append)
-	     *                                 .toString();
-	     * }</pre>
-	     *
-	     * @param <R> type of the result
-	     * @param <A> Type of the accumulator.
-	     * @param pSupplier a function that creates a new result container. For a
-	     *                 parallel execution, this function may be called
-	     *                 multiple times and must return a fresh value each time.
-	     * @param pAccumulator An associative, non-interfering, stateless function for
-	     *   incorporating an additional element into a result
-	     * @param pCombiner An associative, non-interfering, stateless
-	     *   function for combining two values, which must be compatible with the
-	     *   accumulator function
-	     * @return The result of the reduction
-	     */
-		public <A,R> R collect(Supplier<R> pSupplier, BiConsumer<R,? super O> pAccumulator, BiConsumer<R,R> pCombiner) {
+        /**
+         * Performs a mutable reduction operation on the elements of this FailableStream.
+         * A mutable reduction is one in which the reduced value is a mutable result
+         * container, such as an {@code ArrayList}, and elements are incorporated by updating
+         * the state of the result rather than by replacing the result. This produces a result equivalent to:
+         * <pre>{@code
+         *     R result = supplier.get();
+         *     for (T element : this stream)
+         *         accumulator.accept(result, element);
+         *     return result;
+         * }</pre>
+         *
+         * <p>Like {@link #reduce(Object, BinaryOperator)}, {@code collect} operations
+         * can be parallelized without requiring additional synchronization.
+         *
+         * <p>This is a terminal operation.
+         *
+         * \@apiNote There are many existing classes in the JDK whose signatures are
+         * well-suited for use with method references as arguments to {@code collect()}.
+         * For example, the following will accumulate strings into an {@code ArrayList}:
+         * <pre>{@code
+         *     List<String> asList = stringStream.collect(ArrayList::new, ArrayList::add,
+         *                                                ArrayList::addAll);
+         * }</pre>
+         *
+         * <p>The following will take a stream of strings and concatenates them into a
+         * single string:
+         * <pre>{@code
+         *     String concat = stringStream.collect(StringBuilder::new, StringBuilder::append,
+         *                                          StringBuilder::append)
+         *                                 .toString();
+         * }</pre>
+         *
+         * @param <R> type of the result
+         * @param <A> Type of the accumulator.
+         * @param pSupplier a function that creates a new result container. For a
+         *                 parallel execution, this function may be called
+         *                 multiple times and must return a fresh value each time.
+         * @param pAccumulator An associative, non-interfering, stateless function for
+         *   incorporating an additional element into a result
+         * @param pCombiner An associative, non-interfering, stateless
+         *   function for combining two values, which must be compatible with the
+         *   accumulator function
+         * @return The result of the reduction
+         */
+        public <A, R> R collect(Supplier<R> pSupplier, BiConsumer<R, ? super O> pAccumulator, BiConsumer<R, R> pCombiner) {
             makeTerminated();
-			return stream().collect(pSupplier, pAccumulator, pCombiner);
-		}
+            return stream().collect(pSupplier, pAccumulator, pCombiner);
+        }
 
-	    /**
-	     * Performs a reduction on the elements of this stream, using the provided
-	     * identity value and an associative accumulation function, and returns
-	     * the reduced value.  This is equivalent to:
-	     * <pre>{@code
-	     *     T result = identity;
-	     *     for (T element : this stream)
-	     *         result = accumulator.apply(result, element)
-	     *     return result;
-	     * }</pre>
-	     *
-	     * but is not constrained to execute sequentially.
-	     *
-	     * <p>The {@code identity} value must be an identity for the accumulator
-	     * function. This means that for all {@code t},
-	     * {@code accumulator.apply(identity, t)} is equal to {@code t}.
-	     * The {@code accumulator} function must be an associative function.
-	     *
-	     * <p>This is a terminal operation.
-	     *
-	     * \@apiNote Sum, min, max, average, and string concatenation are all special
-	     * cases of reduction. Summing a stream of numbers can be expressed as:
-	     *
-	     * <pre>{@code
-	     *     Integer sum = integers.reduce(0, (a, b) -> a+b);
-	     * }</pre>
-	     *
-	     * or:
-	     *
-	     * <pre>{@code
-	     *     Integer sum = integers.reduce(0, Integer::sum);
-	     * }</pre>
-	     *
-	     * <p>While this may seem a more roundabout way to perform an aggregation
-	     * compared to simply mutating a running total in a loop, reduction
-	     * operations parallelize more gracefully, without needing additional
-	     * synchronization and with greatly reduced risk of data races.
-	     *
-	     * @param pIdentity the identity value for the accumulating function
-	     * @param pAccumulator an associative, non-interfering, stateless
-	     *                    function for combining two values
-	     * @return the result of the reduction
-	     */
-		public O reduce(O pIdentity, BinaryOperator<O> pAccumulator) {
+        /**
+         * Performs a reduction on the elements of this stream, using the provided
+         * identity value and an associative accumulation function, and returns
+         * the reduced value.  This is equivalent to:
+         * <pre>{@code
+         *     T result = identity;
+         *     for (T element : this stream)
+         *         result = accumulator.apply(result, element)
+         *     return result;
+         * }</pre>
+         *
+         * but is not constrained to execute sequentially.
+         *
+         * <p>The {@code identity} value must be an identity for the accumulator
+         * function. This means that for all {@code t},
+         * {@code accumulator.apply(identity, t)} is equal to {@code t}.
+         * The {@code accumulator} function must be an associative function.
+         *
+         * <p>This is a terminal operation.
+         *
+         * \@apiNote Sum, min, max, average, and string concatenation are all special
+         * cases of reduction. Summing a stream of numbers can be expressed as:
+         *
+         * <pre>{@code
+         *     Integer sum = integers.reduce(0, (a, b) -> a+b);
+         * }</pre>
+         *
+         * or:
+         *
+         * <pre>{@code
+         *     Integer sum = integers.reduce(0, Integer::sum);
+         * }</pre>
+         *
+         * <p>While this may seem a more roundabout way to perform an aggregation
+         * compared to simply mutating a running total in a loop, reduction
+         * operations parallelize more gracefully, without needing additional
+         * synchronization and with greatly reduced risk of data races.
+         *
+         * @param pIdentity the identity value for the accumulating function
+         * @param pAccumulator an associative, non-interfering, stateless
+         *                    function for combining two values
+         * @return the result of the reduction
+         */
+        public O reduce(O pIdentity, BinaryOperator<O> pAccumulator) {
             makeTerminated();
-			return stream().reduce(pIdentity, pAccumulator);
-		}
+            return stream().reduce(pIdentity, pAccumulator);
+        }
 
-	    /**
-	     * Returns a stream consisting of the results of applying the given
-	     * function to the elements of this stream.
-	     *
-	     * <p>This is an intermediate operation.
-	     *
-	     * @param <R> The element type of the new stream
-	     * @param pMapper A non-interfering, stateless function to apply to each element
-	     * @return the new stream
-	     */
-		public <R> FailableStream<R> map(FailableFunction<O,R,?> pMapper) {
-		    assertNotTerminated();
-			return new FailableStream<R>(stream.map(Functions.asFunction(pMapper)));
-		}
+        /**
+         * Returns a stream consisting of the results of applying the given
+         * function to the elements of this stream.
+         *
+         * <p>This is an intermediate operation.
+         *
+         * @param <R> The element type of the new stream
+         * @param pMapper A non-interfering, stateless function to apply to each element
+         * @return the new stream
+         */
+        public <R> FailableStream<R> map(FailableFunction<O, R, ?> pMapper) {
+            assertNotTerminated();
+            return new FailableStream<R>(stream.map(Functions.asFunction(pMapper)));
+        }
 
-		/**
-		 * Converts the FailableStream into an equivalent stream.
-		 * @return A stream, which will return the same elements, which this FailableStream would return.
-		 */
-		public Stream<O> stream() {
-			return stream;
-		}
+        /**
+         * Converts the FailableStream into an equivalent stream.
+         * @return A stream, which will return the same elements, which this FailableStream would return.
+         */
+        public Stream<O> stream() {
+            return stream;
+        }
 
-	    /**
-	     * Returns whether all elements of this stream match the provided predicate.
-	     * May not evaluate the predicate on all elements if not necessary for
-	     * determining the result.  If the stream is empty then {@code true} is
-	     * returned and the predicate is not evaluated.
-	     *
-	     * <p>This is a short-circuiting terminal operation.
-	     *
-	     * \@apiNote
-	     * This method evaluates the <em>universal quantification</em> of the
-	     * predicate over the elements of the stream (for all x P(x)).  If the
-	     * stream is empty, the quantification is said to be <em>vacuously
-	     * satisfied</em> and is always {@code true} (regardless of P(x)).
-	     *
-	     * @param pPredicate A non-interfering, stateless predicate to apply to
-	     * elements of this stream
-	     * @return {@code true} If either all elements of the stream match the
-	     * provided predicate or the stream is empty, otherwise {@code false}.
-	     */
-		public boolean allMatch(FailablePredicate<O,?> pPredicate) {
-		    assertNotTerminated();
-			return stream().allMatch(Functions.asPredicate(pPredicate));
-		}
+        /**
+         * Returns whether all elements of this stream match the provided predicate.
+         * May not evaluate the predicate on all elements if not necessary for
+         * determining the result.  If the stream is empty then {@code true} is
+         * returned and the predicate is not evaluated.
+         *
+         * <p>This is a short-circuiting terminal operation.
+         *
+         * \@apiNote
+         * This method evaluates the <em>universal quantification</em> of the
+         * predicate over the elements of the stream (for all x P(x)).  If the
+         * stream is empty, the quantification is said to be <em>vacuously
+         * satisfied</em> and is always {@code true} (regardless of P(x)).
+         *
+         * @param pPredicate A non-interfering, stateless predicate to apply to
+         * elements of this stream
+         * @return {@code true} If either all elements of the stream match the
+         * provided predicate or the stream is empty, otherwise {@code false}.
+         */
+        public boolean allMatch(FailablePredicate<O, ?> pPredicate) {
+            assertNotTerminated();
+            return stream().allMatch(Functions.asPredicate(pPredicate));
+        }
 
-	    /**
-	     * Returns whether any elements of this stream match the provided
-	     * predicate.  May not evaluate the predicate on all elements if not
-	     * necessary for determining the result.  If the stream is empty then
-	     * {@code false} is returned and the predicate is not evaluated.
-	     *
-	     * <p>This is a short-circuiting terminal operation.
-	     *
-	     * \@apiNote
-	     * This method evaluates the <em>existential quantification</em> of the
-	     * predicate over the elements of the stream (for some x P(x)).
-	     *
-	     * @param pPredicate A non-interfering, stateless predicate to apply to
-	     * elements of this stream
-	     * @return {@code true} if any elements of the stream match the provided
-	     * predicate, otherwise {@code false}
-	     */
-		public boolean anyMatch(FailablePredicate<O,?> pPredicate) {
+        /**
+         * Returns whether any elements of this stream match the provided
+         * predicate.  May not evaluate the predicate on all elements if not
+         * necessary for determining the result.  If the stream is empty then
+         * {@code false} is returned and the predicate is not evaluated.
+         *
+         * <p>This is a short-circuiting terminal operation.
+         *
+         * \@apiNote
+         * This method evaluates the <em>existential quantification</em> of the
+         * predicate over the elements of the stream (for some x P(x)).
+         *
+         * @param pPredicate A non-interfering, stateless predicate to apply to
+         * elements of this stream
+         * @return {@code true} if any elements of the stream match the provided
+         * predicate, otherwise {@code false}
+         */
+        public boolean anyMatch(FailablePredicate<O, ?> pPredicate) {
             assertNotTerminated();
             return stream().anyMatch(Functions.asPredicate(pPredicate));
-		}
-	}
+        }
+    }
+
+    /**
+     * Converts the given {@link Stream stream} into a {@link FailableStream}.
+     * This is basically a simplified, reduced version of the {@link Stream}
+     * class, with the same underlying element stream, except that failable
+     * objects, like {@link FailablePredicate}, {@link FailableFunction}, or
+     * {@link FailableConsumer} may be applied, instead of
+     * {@link Predicate}, {@link Function}, or {@link Consumer}. The idea is
+     * to rewrite a code snippet like this:
+     * <pre>
+     *     final List&lt;O&gt; list;
+     *     final Method m;
+     *     final Function&lt;O,String&gt; mapper = (o) -&gt; {
+     *         try {
+     *             return (String) m.invoke(o);
+     *         } catch (Throwable t) {
+     *             throw Functions.rethrow(t);
+     *         }
+     *     };
+     *     final List&lt;String&gt; strList = list.stream()
+     *         .map(mapper).collect(Collectors.toList());
+     *  </pre>
+     *  as follows:
+     *  <pre>
+     *     final List&lt;O&gt; list;
+     *     final Method m;
+     *     final List&lt;String&gt; strList = Functions.stream(list.stream())
+     *         .map((o) -&gt; (String) m.invoke(o)).collect(Collectors.toList());
+     *  </pre>
+     *  While the second version may not be <em>quite</em> as
+     *  efficient (because it depends on the creation of additional,
+     *  intermediate objects, of type FailableStream), it is much more
+     *  concise, and readable, and meets the spirit of Lambdas better
+     *  than the first version.
+     * @param <O> The streams element type.
+     * @param pStream The stream, which is being converted.
+     * @return The {@link FailableStream}, which has been created by
+     *   converting the stream.
+     */
+    public static <O> FailableStream<O> stream(Stream<O> pStream) {
+        return new FailableStream<O>(pStream);
+    }
 
-	/**
-	 * Converts the given {@link Stream stream} into a {@link FailableStream}.
-	 * This is basically a simplified, reduced version of the {@link Stream}
-	 * class, with the same underlying element stream, except that failable
-	 * objects, like {@link FailablePredicate}, {@link FailableFunction}, or
-	 * {@link FailableConsumer} may be applied, instead of
-	 * {@link Predicate}, {@link Function}, or {@link Consumer}. The idea is
-	 * to rewrite a code snippet like this:
-	 * <pre>
-	 *     final List&lt;O&gt; list;
-	 *     final Method m;
-	 *     final Function&lt;O,String&gt; mapper = (o) -&gt; {
-	 *         try {
-	 *             return (String) m.invoke(o);
-	 *         } catch (Throwable t) {
-	 *             throw Functions.rethrow(t);
-	 *         }
-	 *     };
-	 *     final List&lt;String&gt; strList = list.stream()
-	 *         .map(mapper).collect(Collectors.toList());
-	 *  </pre>
-	 *  as follows:
-	 *  <pre>
+    /**
+     * Converts the given {@link Collection} into a {@link FailableStream}.
+     * This is basically a simplified, reduced version of the {@link Stream}
+     * class, with the same underlying element stream, except that failable
+     * objects, like {@link FailablePredicate}, {@link FailableFunction}, or
+     * {@link FailableConsumer} may be applied, instead of
+     * {@link Predicate}, {@link Function}, or {@link Consumer}. The idea is
+     * to rewrite a code snippet like this:
+     * <pre>
+     *     final List&lt;O&gt; list;
+     *     final Method m;
+     *     final Function&lt;O,String&gt; mapper = (o) -&gt; {
+     *         try {
+     *             return (String) m.invoke(o);
+     *         } catch (Throwable t) {
+     *             throw Functions.rethrow(t);
+     *         }
+     *     };
+     *     final List&lt;String&gt; strList = list.stream()
+     *         .map(mapper).collect(Collectors.toList());
+     *  </pre>
+     *  as follows:
+     *  <pre>
      *     final List&lt;O&gt; list;
      *     final Method m;
      *     final List&lt;String&gt; strList = Functions.stream(list.stream())
@@ -369,12 +412,12 @@ public class Streams {
      *  intermediate objects, of type FailableStream), it is much more
      *  concise, and readable, and meets the spirit of Lambdas better
      *  than the first version.
-	 * @param <O> The streams element type.
-	 * @param pStream The stream, which is being converted.
-	 * @return The {@link FailableStream}, which has been created by
-	 *   converting the stream.
-	 */
-	public static <O> FailableStream<O> stream(Stream<O> pStream) {
-		return new FailableStream<O>(pStream);
-	}
+     * @param <O> The streams element type.
+     * @param pStream The stream, which is being converted.
+     * @return The {@link FailableStream}, which has been created by
+     *   converting the stream.
+     */
+    public static <O> FailableStream<O> stream(Collection<O> pStream) {
+        return stream(pStream.stream());
+    }
 }
diff --git a/src/test/java/org/apache/commons/lang3/StreamsTest.java b/src/test/java/org/apache/commons/lang3/StreamsTest.java
index 9ad8e78..3ce713d 100644
--- a/src/test/java/org/apache/commons/lang3/StreamsTest.java
+++ b/src/test/java/org/apache/commons/lang3/StreamsTest.java
@@ -16,7 +16,9 @@
  */
 package org.apache.commons.lang3;
 
-import static org.junit.jupiter.api.Assertions.*;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertSame;
+import static org.junit.jupiter.api.Assertions.fail;
 
 import java.lang.reflect.UndeclaredThrowableException;
 import java.util.ArrayList;
@@ -62,7 +64,7 @@ class StreamsTest {
         }
     }
 
-    protected <T extends Throwable> FailableConsumer<String,T> asIntConsumer(T pThrowable) {
+    protected <T extends Throwable> FailableConsumer<String, T> asIntConsumer(T pThrowable) {
         return (s) -> {
             final Integer i = Integer.valueOf(s);
             if (i.intValue() == 4) {
@@ -105,7 +107,9 @@ class StreamsTest {
         final List<String> input = Arrays.asList("1", "2", "3", "4", "5", "6");
         final List<Integer> output = Functions.stream(input)
                 .map((s) -> Integer.valueOf(s))
-                .filter((i) -> { return i.intValue() %2 == 0;})
+                .filter((i) -> {
+                    return i.intValue() %2 == 0;
+                })
                 .collect(Collectors.toList());
         assertEvenNumbers(output);
     }
@@ -117,7 +121,7 @@ class StreamsTest {
         }
     }
 
-    protected <T extends Throwable> FailablePredicate<Integer,T> asIntPredicate(T pThrowable) {
+    protected <T extends Throwable> FailablePredicate<Integer, T> asIntPredicate(T pThrowable) {
         return (i) -> {
             if (i.intValue() == 5) {
                 if (pThrowable != null) {