You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@commons.apache.org by gg...@apache.org on 2022/08/12 18:36:13 UTC
[commons-lang] 03/03: Add Streams.of(Iterator)
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
commit 717f163a6df989499dc5df2f1de2e1b6a23ba1e8
Author: Gary Gregory <ga...@gmail.com>
AuthorDate: Fri Aug 12 14:36:02 2022 -0400
Add Streams.of(Iterator)
---
.../java/org/apache/commons/lang3/StringUtils.java | 39 +++-------------------
.../org/apache/commons/lang3/stream/Streams.java | 14 ++++++++
.../apache/commons/lang3/stream/StreamsTest.java | 12 +++++++
3 files changed, 30 insertions(+), 35 deletions(-)
diff --git a/src/main/java/org/apache/commons/lang3/StringUtils.java b/src/main/java/org/apache/commons/lang3/StringUtils.java
index 573b652fd..b1f198fb1 100644
--- a/src/main/java/org/apache/commons/lang3/StringUtils.java
+++ b/src/main/java/org/apache/commons/lang3/StringUtils.java
@@ -29,11 +29,11 @@ import java.util.Objects;
import java.util.Set;
import java.util.function.Supplier;
import java.util.regex.Pattern;
-import java.util.stream.Stream;
import org.apache.commons.lang3.function.Suppliers;
import org.apache.commons.lang3.function.ToBooleanBiFunction;
import org.apache.commons.lang3.stream.LangCollectors;
+import org.apache.commons.lang3.stream.Streams;
/**
* <p>Operations on {@link java.lang.String} that are
@@ -124,8 +124,6 @@ import org.apache.commons.lang3.stream.LangCollectors;
//@Immutable
public class StringUtils {
- private static final int STRING_BUILDER_SIZE = 256;
-
// Performance testing notes (JDK 1.4, Jul03, scolebourne)
// Whitespace:
// Character.isWhitespace() is faster than WHITESPACE.indexOf()
@@ -4386,7 +4384,6 @@ public class StringUtils {
* @since 2.0
*/
public static String join(final Iterator<?> iterator, final char separator) {
-
// handle null, zero and one elements before building a buffer
if (iterator == null) {
return null;
@@ -4394,22 +4391,7 @@ public class StringUtils {
if (!iterator.hasNext()) {
return EMPTY;
}
-
- // two or more elements
- final StringBuilder buf = new StringBuilder(STRING_BUILDER_SIZE); // Java default is 16, probably too small
-
- while (iterator.hasNext()) {
- final Object obj = iterator.next();
- if (obj != null) {
- buf.append(obj);
- }
- if (iterator.hasNext()) {
- buf.append(separator);
- }
-
- }
-
- return buf.toString();
+ return Streams.of(iterator).collect(LangCollectors.joining(toStringOrEmpty(String.valueOf(separator)), EMPTY, EMPTY, StringUtils::toStringOrEmpty));
}
/**
@@ -4433,20 +4415,7 @@ public class StringUtils {
if (!iterator.hasNext()) {
return EMPTY;
}
-
- // two or more elements
- final StringBuilder buf = new StringBuilder(STRING_BUILDER_SIZE); // Java default is 16, probably too small
-
- while (iterator.hasNext()) {
- final Object obj = iterator.next();
- if (obj != null) {
- buf.append(obj);
- }
- if (separator != null && iterator.hasNext()) {
- buf.append(separator);
- }
- }
- return buf.toString();
+ return Streams.of(iterator).collect(LangCollectors.joining(toStringOrEmpty(separator), EMPTY, EMPTY, StringUtils::toStringOrEmpty));
}
/**
@@ -4727,7 +4696,7 @@ public class StringUtils {
* {@code endIndex > array.length()}
*/
public static String join(final Object[] array, final String delimiter, final int startIndex, final int endIndex) {
- return array != null ? Stream.of(array).skip(startIndex).limit(Math.max(0, endIndex - startIndex))
+ return array != null ? Streams.of(array).skip(startIndex).limit(Math.max(0, endIndex - startIndex))
.collect(LangCollectors.joining(delimiter, EMPTY, EMPTY, StringUtils::toStringOrEmpty)) : null;
}
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 ee576c723..6ae7d1aa4 100644
--- a/src/main/java/org/apache/commons/lang3/stream/Streams.java
+++ b/src/main/java/org/apache/commons/lang3/stream/Streams.java
@@ -20,10 +20,12 @@ import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
+import java.util.Iterator;
import java.util.List;
import java.util.Objects;
import java.util.Set;
import java.util.Spliterator;
+import java.util.Spliterators;
import java.util.Spliterators.AbstractSpliterator;
import java.util.function.BiConsumer;
import java.util.function.BinaryOperator;
@@ -653,6 +655,18 @@ public class Streams {
return iterable == null ? Stream.empty() : StreamSupport.stream(iterable.spliterator(), false);
}
+ /**
+ * Creates a stream on the given Iterator.
+ *
+ * @param <E> the type of elements in the Iterator.
+ * @param iterator the Iterator to stream or null.
+ * @return a new Stream or {@link Stream#empty()} if the Iterator is null.
+ * @since 3.13.0
+ */
+ public static <E> Stream<E> of(final Iterator<E> iterator) {
+ return iterator == null ? Stream.empty() : StreamSupport.stream(Spliterators.spliteratorUnknownSize(iterator, Spliterator.ORDERED), false);
+ }
+
/**
* Null-safe version of {@link Stream#of(Object[])}.
*
diff --git a/src/test/java/org/apache/commons/lang3/stream/StreamsTest.java b/src/test/java/org/apache/commons/lang3/stream/StreamsTest.java
index 073e9cc71..c15f95999 100644
--- a/src/test/java/org/apache/commons/lang3/stream/StreamsTest.java
+++ b/src/test/java/org/apache/commons/lang3/stream/StreamsTest.java
@@ -31,6 +31,7 @@ import java.lang.reflect.UndeclaredThrowableException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Hashtable;
+import java.util.Iterator;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
@@ -199,6 +200,17 @@ public class StreamsTest extends AbstractLangTest {
assertEquals(0, Streams.of(input).collect(Collectors.toList()).size());
}
+ @Test
+ public void testOfIteratorNotNull() {
+ assertEquals(2, Streams.of(Arrays.asList("A", "B").iterator()).collect(Collectors.toList()).size());
+ }
+
+ @Test
+ public void testOfIteratorNull() {
+ final Iterator<String> input = null;
+ assertEquals(0, Streams.of(input).collect(Collectors.toList()).size());
+ }
+
@Test
public void testSimpleStreamFilter() {
final List<String> input = Arrays.asList("1", "2", "3", "4", "5", "6");