This is an automated email from the ASF dual-hosted git repository.
ggregory 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 8f48ed8 Add Streams.failableStream(Collection) and deprecate misnamed
stream(Collection).
8f48ed8 is described below
commit 8f48ed8adf7f7b35d3b24e2f2511969d6705ec39
Author: Gary Gregory <garydgreg...@gmail.com>
AuthorDate: Thu Nov 18 14:52:55 2021 -0500
Add Streams.failableStream(Collection) and deprecate misnamed
stream(Collection).
Add Streams.failableStream(Stream) and deprecate misnamed
stream(Stream).
---
src/changes/changes.xml | 2 +
.../org/apache/commons/lang3/stream/Streams.java | 349 +++++++++++++--------
2 files changed, 224 insertions(+), 127 deletions(-)
diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index 01d241c..da516cd 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -99,6 +99,8 @@ The <action> type attribute can be add,update,fix,remove.
<action type="add" dev="ggregory" due-to="Gary
Gregory">Add MethodInvokers.</action>
<action type="add" dev="ggregory" due-to="Gary
Gregory">Add Streams.nullSafeStream(Collection).</action>
<action type="add" dev="ggregory" due-to="Gary
Gregory">Add Streams.toStream(Collection).</action>
+ <action type="add" dev="ggregory" due-to="Gary
Gregory">Add Streams.failableStream(Collection) and deprecate misnamed
stream(Collection).</action>
+ <action type="add" dev="ggregory" due-to="Gary
Gregory">Add Streams.failableStream(Stream) and deprecate misnamed
stream(Stream).</action>
<!-- UPDATE -->
<action type="update" dev="ggregory" due-to="Dependabot,
Gary Gregory">Bump spotbugs-maven-plugin from 4.2.0 to 4.4.2.2 #735, #808,
#822.</action>
<action type="update" dev="ggregory" due-to="Dependabot,
XenoAmess">Bump Bump actions/cache from v2.1.4 to v2.1.6 #742, #752,
#764.</action>
diff --git a/src/main/java/org/apache/commons/lang3/stream/Streams.java
b/src/main/java/org/apache/commons/lang3/stream/Streams.java
index 144d054..805e994 100644
--- a/src/main/java/org/apache/commons/lang3/stream/Streams.java
+++ b/src/main/java/org/apache/commons/lang3/stream/Streams.java
@@ -39,29 +39,35 @@ import org.apache.commons.lang3.function.FailableFunction;
import org.apache.commons.lang3.function.FailablePredicate;
/**
- * Provides utility functions, and classes for working with the
- * {@code java.util.stream} 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 {@link Exception}. This enforces the use of constructs like:
+ * Provides utility functions, and classes for working with the {@code
java.util.stream} 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 {@link
Exception}. This enforces the use of constructs
+ * like:
+ *
* <pre>
- * Consumer<java.lang.reflect.Method> consumer = m -> {
- * try {
- * m.invoke(o, args);
- * } catch (Throwable t) {
- * throw Failable.rethrow(t);
- * }
- * };
- * stream.forEach(consumer);
+ * {@code
+ * Consumer<java.lang.reflect.Method> consumer = m -> {
+ * try {
+ * m.invoke(o, args);
+ * } catch (Throwable t) {
+ * throw Failable.rethrow(t);
+ * }
+ * };
+ * stream.forEach(consumer);
+ * }
* </pre>
* <p>
* Using a {@link FailableStream}, this can be rewritten as follows:
* </p>
+ *
* <pre>
- * Streams.failable(stream).forEach((m) -> m.invoke(o, args));
+ * {@code
+ * Streams.failable(stream).forEach((m) -> 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.
+ *
+ * Obviously, the second version is much more concise and the spirit of Lambda
expressions is met better than in the
+ * first version.
*
* @see Stream
* @see Failable
@@ -72,23 +78,23 @@ public class Streams {
/**
* A Collector type for arrays.
*
- * @param <O> The array type.
+ * @param <E> The array type.
*/
- public static class ArrayCollector<O> implements Collector<O, List<O>,
O[]> {
+ public static class ArrayCollector<E> implements Collector<E, List<E>,
E[]> {
private static final Set<Characteristics> characteristics =
Collections.emptySet();
- private final Class<O> elementType;
+ private final Class<E> elementType;
/**
* Constructs a new instance for the given element type.
*
* @param elementType The element type.
*/
- public ArrayCollector(final Class<O> elementType) {
+ public ArrayCollector(final Class<E> elementType) {
this.elementType = Objects.requireNonNull(elementType,
"elementType");
}
@Override
- public BiConsumer<List<O>, O> accumulator() {
+ public BiConsumer<List<E>, E> accumulator() {
return List::add;
}
@@ -98,7 +104,7 @@ public class Streams {
}
@Override
- public BinaryOperator<List<O>> combiner() {
+ public BinaryOperator<List<E>> combiner() {
return (left, right) -> {
left.addAll(right);
return left;
@@ -106,12 +112,12 @@ public class Streams {
}
@Override
- public Function<List<O>, O[]> finisher() {
+ public Function<List<E>, E[]> finisher() {
return list -> list.toArray(ArrayUtils.newInstance(elementType,
list.size()));
}
@Override
- public Supplier<List<O>> supplier() {
+ public Supplier<List<E>> supplier() {
return ArrayList::new;
}
}
@@ -119,11 +125,11 @@ public class Streams {
/**
* A reduced, and simplified version of a {@link Stream} with failable
method signatures.
*
- * @param <O> The streams element type.
+ * @param <T> The streams element type.
*/
- public static class FailableStream<O extends Object> {
+ public static class FailableStream<T extends Object> {
- private Stream<O> stream;
+ private Stream<T> stream;
private boolean terminated;
/**
@@ -131,48 +137,48 @@ public class Streams {
*
* @param stream The stream.
*/
- public FailableStream(final Stream<O> stream) {
+ public FailableStream(final Stream<T> stream) {
this.stream = 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.
+ * 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.
* </p>
*
- * Note 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)).
+ * Note 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 predicate 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}.
+ * @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(final FailablePredicate<O, ?> predicate) {
+ public boolean allMatch(final FailablePredicate<T, ?> predicate) {
assertNotTerminated();
return stream().allMatch(Failable.asPredicate(predicate));
}
/**
- * 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.
+ * 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.
* </p>
*
- * Note This method evaluates the <em>existential quantification</em>
of the predicate over the elements of
- * the stream (for some x P(x)).
+ * Note This method evaluates the <em>existential quantification</em>
of the predicate over the elements of the stream
+ * (for some x P(x)).
*
* @param predicate 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(final FailablePredicate<O, ?> predicate) {
+ public boolean anyMatch(final FailablePredicate<T, ?> predicate) {
assertNotTerminated();
return stream().anyMatch(Failable.asPredicate(predicate));
}
@@ -189,15 +195,14 @@ public class Streams {
}
/**
- * 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.
+ * 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.)
+ * 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>
*
* <p>
@@ -205,16 +210,15 @@ public class Streams {
* </p>
*
* <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.
+ * 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.
* </p>
*
* Note The following will accumulate strings into an ArrayList:
*
* <pre>
- * {@code
+ * {@code
* List<String> asList = stringStream.collect(Collectors.toList());
* }
* </pre>
@@ -224,18 +228,17 @@ public class Streams {
* </p>
*
* <pre>
- * {@code
+ * {@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:
+ * The following will classify {@code Person} objects by state and
city, cascading two {@code Collector}s together:
* </p>
*
* <pre>
- * {@code
+ * {@code
* Map<String, Map<String, List<Person>>> peopleByStateAndCity =
personStream
* .collect(Collectors.groupingBy(Person::getState,
Collectors.groupingBy(Person::getCity)));
* }
@@ -248,16 +251,15 @@ public class Streams {
* @see #collect(Supplier, BiConsumer, BiConsumer)
* @see Collectors
*/
- public <A, R> R collect(final Collector<? super O, A, R> collector) {
+ public <A, R> R collect(final Collector<? super T, A, R> collector) {
makeTerminated();
return stream().collect(collector);
}
/**
- * 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:
+ * 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
@@ -269,20 +271,19 @@ public class Streams {
* </pre>
*
* <p>
- * Like {@link #reduce(Object, BinaryOperator)}, {@code collect}
operations can be parallelized without
- * requiring additional synchronization.
+ * Like {@link #reduce(Object, BinaryOperator)}, {@code collect}
operations can be parallelized without requiring
+ * additional synchronization.
* </p>
*
* <p>
* This is a terminal operation.
* </p>
*
- * Note 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}:
+ * Note 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
+ * {@code
* List<String> asList = stringStream.collect(ArrayList::new,
ArrayList::add, ArrayList::addAll);
* }
* </pre>
@@ -292,24 +293,22 @@ public class Streams {
* </p>
*
* <pre>
- * {@code
- * String concat = stringStream.collect(StringBuilder::new,
StringBuilder::append, StringBuilder::append)
- * .toString();
+ * {@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 supplier 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 accumulator An associative, non-interfering, stateless
function for incorporating an additional
- * element into a result
+ * @param supplier 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 accumulator An associative, non-interfering, stateless
function for incorporating an additional element into a
+ * result
* @param combiner 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(final Supplier<R> supplier, final
BiConsumer<R, ? super O> accumulator,
- final BiConsumer<R, R> combiner) {
+ public <A, R> R collect(final Supplier<R> supplier, final
BiConsumer<R, ? super T> accumulator, final BiConsumer<R, R> combiner) {
makeTerminated();
return stream().collect(supplier, accumulator, combiner);
}
@@ -325,7 +324,7 @@ public class Streams {
* included.
* @return the new stream
*/
- public FailableStream<O> filter(final FailablePredicate<O, ?>
predicate) {
+ public FailableStream<T> filter(final FailablePredicate<T, ?>
predicate) {
assertNotTerminated();
stream = stream.filter(Failable.asPredicate(predicate));
return this;
@@ -339,16 +338,15 @@ public class Streams {
* </p>
*
* <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.
+ * 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.
* </p>
*
* @param action a non-interfering action to perform on the elements
*/
- public void forEach(final FailableConsumer<O, ?> action) {
+ public void forEach(final FailableConsumer<T, ?> action) {
makeTerminated();
stream().forEach(Failable.asConsumer(action));
}
@@ -374,7 +372,7 @@ public class Streams {
* @param mapper A non-interfering, stateless function to apply to
each element
* @return the new stream
*/
- public <R> FailableStream<R> map(final FailableFunction<O, R, ?>
mapper) {
+ public <R> FailableStream<R> map(final FailableFunction<T, R, ?>
mapper) {
assertNotTerminated();
return new
FailableStream<>(stream.map(Failable.asFunction(mapper)));
}
@@ -395,20 +393,20 @@ public class Streams {
* 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.
+ * 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>
*
* <p>
* This is a terminal operation.
* </p>
*
- * Note Sum, min, max, average, and string concatenation are all
special cases of reduction. Summing a
- * stream of numbers can be expressed as:
+ * Note Sum, min, max, average, and string concatenation are all
special cases of reduction. Summing a stream of numbers
+ * can be expressed as:
*
* <pre>
- * {@code
+ * {@code
* Integer sum = integers.reduce(0, (a, b) -> a + b);
* }
* </pre>
@@ -416,22 +414,22 @@ public class Streams {
* or:
*
* <pre>
- * {@code
+ * {@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.
+ * 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.
* </p>
*
* @param identity the identity value for the accumulating function
* @param accumulator an associative, non-interfering, stateless
function for combining two values
* @return the result of the reduction
*/
- public O reduce(final O identity, final BinaryOperator<O> accumulator)
{
+ public T reduce(final T identity, final BinaryOperator<T> accumulator)
{
makeTerminated();
return stream().reduce(identity, accumulator);
}
@@ -441,7 +439,7 @@ public class Streams {
*
* @return A stream, which will return the same elements, which this
FailableStream would return.
*/
- public Stream<O> stream() {
+ public Stream<T> stream() {
return stream;
}
}
@@ -476,44 +474,92 @@ public class Streams {
}
/**
- * 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
+ * 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>
+ * {@code
+ * final List<O> list;
+ * final Method m;
+ * final Function<O, String> mapper = (o) -> {
+ * try {
+ * return (String) m.invoke(o);
+ * } catch (Throwable t) {
+ * throw Failable.rethrow(t);
+ * }
+ * };
+ * final List<String> strList =
list.stream().map(mapper).collect(Collectors.toList());
+ * }
+ * </pre>
+ *
+ * as follows:
+ *
+ * <pre>
+ * {@code
+ * final List<O> list;
+ * final Method m;
+ * final List<String> strList = Failable.stream(list.stream()).map((o) ->
(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 <E> The streams element type.
+ * @param collection The stream, which is being converted.
+ * @return The {@link FailableStream}, which has been created by
converting the stream.
+ * @deprecated Use {@link #failableStream(Collection)}.
+ */
+ @Deprecated
+ public static <E> FailableStream<E> stream(final Collection<E> collection)
{
+ return failableStream(collection);
+ }
+
+ /**
+ * 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<O> list;
+ * {@code
+ * final List<O> list;
* final Method m;
- * final Function<O, String> mapper = (o) -> {
+ * final Function<O, String> mapper = (o) -> {
* try {
* return (String) m.invoke(o);
* } catch (Throwable t) {
* throw Failable.rethrow(t);
* }
* };
- * final List<String> strList =
list.stream().map(mapper).collect(Collectors.toList());
+ * final List<String> strList =
list.stream().map(mapper).collect(Collectors.toList());
+ * }
* </pre>
*
* as follows:
*
* <pre>
- * final List<O> list;
+ * {@code
+ * final List<O> list;
* final Method m;
- * final List<String> strList =
Failable.stream(list.stream()).map((o) -> (String) m.invoke(o))
- * .collect(Collectors.toList());
+ * final List<String> strList = Failable.stream(list.stream()).map((o) ->
(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.
+ * 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 <T> The streams element type.
* @param stream The stream, which is being converted.
* @return The {@link FailableStream}, which has been created by
converting the stream.
- * TODO Rename to failableStream()
+ * @since 3.13.0
*/
- public static <O> FailableStream<O> stream(final Collection<O> stream) {
- return stream(toStream(stream));
+ public static <T> FailableStream<T> failableStream(final Collection<T>
stream) {
+ return failableStream(toStream(stream));
}
/**
@@ -523,47 +569,96 @@ public class Streams {
* {@link Predicate}, {@link Function}, or {@link Consumer}. The idea is
to rewrite a code snippet like this:
*
* <pre>
- * final List<O> list;
+ * {@code
+ * final List<O> list;
* final Method m;
- * final Function<O, String> mapper = (o) -> {
+ * final Function<O, String> mapper = (o) -> {
* try {
* return (String) m.invoke(o);
* } catch (Throwable t) {
* throw Failable.rethrow(t);
* }
* };
- * final List<String> strList =
list.stream().map(mapper).collect(Collectors.toList());
+ * final List<String> strList =
list.stream().map(mapper).collect(Collectors.toList());
+ * }
* </pre>
*
* as follows:
*
* <pre>
- * final List<O> list;
+ * {@code
+ * final List<O> list;
* final Method m;
- * final List<String> strList =
Failable.stream(list.stream()).map((o) -> (String) m.invoke(o))
- * .collect(Collectors.toList());
+ * final List<String> strList = Failable.stream(list.stream()).map((o) ->
(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.
+ * 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 <T> The streams element type.
* @param stream The stream, which is being converted.
* @return The {@link FailableStream}, which has been created by
converting the stream.
+ * @since 3.13.0
*/
- public static <O> FailableStream<O> stream(final Stream<O> stream) {
+ public static <T> FailableStream<T> failableStream(final Stream<T> stream)
{
return new FailableStream<>(stream);
}
/**
+ * 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>
+ * {@code
+ * final List<O> list;
+ * final Method m;
+ * final Function<O, String> mapper = (o) -> {
+ * try {
+ * return (String) m.invoke(o);
+ * } catch (Throwable t) {
+ * throw Failable.rethrow(t);
+ * }
+ * };
+ * final List<String> strList =
list.stream().map(mapper).collect(Collectors.toList());
+ * }
+ * </pre>
+ *
+ * as follows:
+ *
+ * <pre>
+ * {@code
+ * final List<O> list;
+ * final Method m;
+ * final List<String> strList = Failable.stream(list.stream()).map((o) ->
(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 <T> The streams element type.
+ * @param stream The stream, which is being converted.
+ * @return The {@link FailableStream}, which has been created by
converting the stream.
+ * @deprecated Use {@link #failableStream(Stream)}.
+ */
+ @Deprecated
+ public static <T> FailableStream<T> stream(final Stream<T> stream) {
+ return failableStream(stream);
+ }
+
+ /**
* Returns a {@code Collector} that accumulates the input elements into a
new array.
*
* @param pElementType Type of an element in the array.
- * @param <O> the type of the input elements
+ * @param <T> the type of the input elements
* @return a {@code Collector} which collects all the input elements into
an array, in encounter order
*/
- public static <O extends Object> Collector<O, ?, O[]> toArray(final
Class<O> pElementType) {
+ public static <T extends Object> Collector<T, ?, T[]> toArray(final
Class<T> pElementType) {
return new ArrayCollector<>(pElementType);
}
