:trollface: 调整mapIdx、filterIdx、peekIdx、forEachIdx的并行流逻辑，添加toIdxMap函数，添加transform接口方法

hutool-core/src/main/java/cn/hutool/core/stream/AbstractEnhancedWrappedStream.java

@@ -19,7 +19,7 @@ public abstract class AbstractEnhancedWrappedStream<T, S extends AbstractEnhance
 	/**
 	 * 原始流实例
 	 */
-	protected final Stream<T> stream;
+	protected Stream<T> stream;
 
 	/**
 	 * 获取被包装的元素流实例

hutool-core/src/main/java/cn/hutool/core/stream/EasyStream.java

@@ -263,6 +263,18 @@ public class EasyStream<T> extends AbstractEnhancedWrappedStream<T, EasyStream<T
 		return new EasyStream<>(stream);
 	}
 
+	/**
+	 * 转换为子类实现
+	 *
+	 * @param stream 流
+	 * @return 子类实现
+	 */
+	@Override
+	public EasyStream<T> transform(Stream<T> stream) {
+		this.stream = stream;
+		return this;
+	}
+
 	/**
 	 * 建造者
 	 *

hutool-core/src/main/java/cn/hutool/core/stream/EntryStream.java

@@ -756,6 +756,18 @@ public class EntryStream<K, V> extends AbstractEnhancedWrappedStream<Map.Entry<K
 		return new EntryStream<>(stream);
 	}
 
+	/**
+	 * 转换为子类实现
+	 *
+	 * @param stream 流
+	 * @return 子类实现
+	 */
+	@Override
+	public EntryStream<K, V> transform(Stream<Map.Entry<K, V>> stream) {
+		this.stream = stream;
+		return this;
+	}
+
 	/**
 	 * key重复时直接抛出异常
 	 */

hutool-core/src/main/java/cn/hutool/core/stream/TerminableWrappedStream.java

@@ -181,14 +181,36 @@ public interface TerminableWrappedStream<T, S extends TerminableWrappedStream<T,
 		Objects.requireNonNull(valueMapper);
 		Objects.requireNonNull(mergeFunction);
 		Objects.requireNonNull(mapSupplier);
-		return unwrap().collect(Collectors.toMap(keyMapper, valueMapper, mergeFunction, mapSupplier));
+		return unwrap().collect(CollectorUtil.toMap(keyMapper, valueMapper, mergeFunction, mapSupplier));
 	}
 
+	/**
+	 * 转换为map，key为下标,value为元素
+	 *
+	 * @return map
+	 */
+	default Map<Integer, T> toIdxMap() {
+		return toIdxMap(Function.identity());
+	}
+
+	/**
+	 * 转换为map，key为下标,value为给定操作执行后的返回值
+	 *
+	 * @param valueMapper 指定value操作
+	 * @param <U>         value类型
+	 * @return map
+	 */
+	default <U> Map<Integer, U> toIdxMap(Function<? super T, ? extends U> valueMapper) {
+		final MutableInt index = new MutableInt(NOT_FOUND_ELEMENT_INDEX);
+		return EasyStream.of(toList()).toMap(e -> index.incrementAndGet(), valueMapper, (l, r) -> r);
+	}
+
+
 	/**
 	 * <p>将集合转换为树，默认用 {@code parentId == null} 来判断树的根节点
 	 * 因为需要在当前传入数据里查找，所以这是一个结束操作 <br>
 	 *
-	 * @param idGetter       id的getter对应的lambda，可以写作 {@code Student::getId} 会过滤掉id为null的元素
+	 * @param idGetter       id的getter对应的lambda，可以写作 {@code Student::getId}
 	 * @param pIdGetter      parentId的getter对应的lambda，可以写作 {@code Student::getParentId}
 	 * @param childrenSetter children的setter对应的lambda，可以写作{ @code Student::setChildren}
 	 * @param <R>            此处是id、parentId的泛型限制
@@ -211,7 +233,7 @@ public interface TerminableWrappedStream<T, S extends TerminableWrappedStream<T,
 	 * 将集合转换为树，自定义根节点的判断条件
 	 * 因为需要在当前传入数据里查找，所以这是一个结束操作
 	 *
-	 * @param idGetter        id的getter对应的lambda，可以写作 {@code Student::getId} 会过滤掉id为null的元素
+	 * @param idGetter        id的getter对应的lambda，可以写作 {@code Student::getId}
 	 * @param pIdGetter       parentId的getter对应的lambda，可以写作 {@code Student::getParentId}
 	 * @param childrenSetter  children的setter对应的lambda，可以写作 {@code Student::setChildren}
 	 * @param parentPredicate 树顶部的判断条件，可以写作 {@code s -> Objects.equals(s.getParentId(),0L) }
@@ -535,7 +557,8 @@ public interface TerminableWrappedStream<T, S extends TerminableWrappedStream<T,
 	default void forEachIdx(final BiConsumer<? super T, Integer> action) {
 		Objects.requireNonNull(action);
 		if (isParallel()) {
-			unwrap().forEach(e -> action.accept(e, NOT_FOUND_ELEMENT_INDEX));
+			EasyStream.of(toIdxMap().entrySet()).parallel(isParallel())
+					.forEach(e -> action.accept(e.getValue(), e.getKey()));
 		} else {
 			final MutableInt index = new MutableInt(NOT_FOUND_ELEMENT_INDEX);
 			unwrap().forEach(e -> action.accept(e, index.incrementAndGet()));
@@ -551,7 +574,9 @@ public interface TerminableWrappedStream<T, S extends TerminableWrappedStream<T,
 	default void forEachOrderedIdx(final BiConsumer<? super T, Integer> action) {
 		Objects.requireNonNull(action);
 		if (isParallel()) {
-			unwrap().forEachOrdered(e -> action.accept(e, NOT_FOUND_ELEMENT_INDEX));
+			EasyStream.of(toIdxMap().entrySet())
+					.parallel(isParallel())
+					.forEachOrdered(e -> action.accept(e.getValue(), e.getKey()));
 		} else {
 			final MutableInt index = new MutableInt(NOT_FOUND_ELEMENT_INDEX);
 			unwrap().forEachOrdered(e -> action.accept(e, index.incrementAndGet()));

hutool-core/src/main/java/cn/hutool/core/stream/TransformableWrappedStream.java

@@ -9,19 +9,10 @@ import cn.hutool.core.map.MapUtil;
 import cn.hutool.core.map.SafeConcurrentHashMap;
 import cn.hutool.core.util.ArrayUtil;
 
-import java.util.HashSet;
+import java.util.*;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
-import java.util.Set;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
-import java.util.function.BiConsumer;
+import java.util.function.*;
-import java.util.function.BiFunction;
-import java.util.function.BiPredicate;
-import java.util.function.Consumer;
-import java.util.function.Function;
-import java.util.function.Predicate;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
@@ -51,8 +42,8 @@ public interface TransformableWrappedStream<T, S extends TransformableWrappedStr
 			final Iterable<U> other,
 			final BiFunction<? super T, ? super U, ? extends R> zipper) {
 		Objects.requireNonNull(zipper);
-		final Map<Integer, T> idxIdentityMap = mapIdx((e, idx) -> MapUtil.entry(idx, e)).collect(CollectorUtil.entryToMap());
+		Map<Integer, T> idxIdentityMap = mapIdx((e, idx) -> MapUtil.entry(idx, e)).collect(CollectorUtil.entryToMap());
-		final Map<Integer, U> idxOtherMap = EasyStream.of(other).mapIdx((e, idx) -> MapUtil.entry(idx, e)).collect(CollectorUtil.entryToMap());
+		Map<Integer, U> idxOtherMap = EasyStream.of(other).mapIdx((e, idx) -> MapUtil.entry(idx, e)).collect(CollectorUtil.entryToMap());
 		if (idxIdentityMap.size() <= idxOtherMap.size()) {
 			return EasyStream.of(idxIdentityMap.keySet(), isParallel()).map(k -> zipper.apply(idxIdentityMap.get(k), idxOtherMap.get(k)));
 		}
@@ -259,8 +250,7 @@ public interface TransformableWrappedStream<T, S extends TransformableWrappedStr
 	// region ============ peek ============
 
 	/**
-	 * 返回与指定函数将元素作为参数执行后组成的流。操作带下标，并行流时下标永远为-1
+	 * 返回与指定函数将元素作为参数执行后组成的流。操作带下标
-	 * 这是一个无状态中间操作
 	 *
 	 * @param action 指定的函数
 	 * @return 返回叠加操作后的FastStream
@@ -278,7 +268,11 @@ public interface TransformableWrappedStream<T, S extends TransformableWrappedStr
 	default S peekIdx(final BiConsumer<? super T, Integer> action) {
 		Objects.requireNonNull(action);
 		if (isParallel()) {
-			return peek(e -> action.accept(e, NOT_FOUND_ELEMENT_INDEX));
+			final Map<Integer, T> idxMap = easyStream().toIdxMap();
+			return transform(EasyStream.of(idxMap.entrySet())
+					.parallel(isParallel())
+					.peek(e -> action.accept(e.getValue(), e.getKey()))
+					.map(Map.Entry::getValue));
 		} else {
 			final AtomicInteger index = new AtomicInteger(NOT_FOUND_ELEMENT_INDEX);
 			return peek(e -> action.accept(e, index.incrementAndGet()));
@@ -370,8 +364,7 @@ public interface TransformableWrappedStream<T, S extends TransformableWrappedStr
 	}
 
 	/**
-	 * 过滤元素，返回与指定断言匹配的元素组成的流，断言带下标，并行流时下标永远为-1
+	 * 过滤元素，返回与指定断言匹配的元素组成的流，断言带下标
-	 * 这是一个无状态中间操作
 	 *
 	 * @param predicate 断言
 	 * @return 返回叠加过滤操作后的流
@@ -379,7 +372,11 @@ public interface TransformableWrappedStream<T, S extends TransformableWrappedStr
 	default S filterIdx(final BiPredicate<? super T, Integer> predicate) {
 		Objects.requireNonNull(predicate);
 		if (isParallel()) {
-			return filter(e -> predicate.test(e, NOT_FOUND_ELEMENT_INDEX));
+			final Map<Integer, T> idxMap = easyStream().toIdxMap();
+			return transform(EasyStream.of(idxMap.entrySet())
+					.parallel(isParallel())
+					.filter(e -> predicate.test(e.getValue(), e.getKey()))
+					.map(Map.Entry::getValue));
 		} else {
 			final MutableInt index = new MutableInt(NOT_FOUND_ELEMENT_INDEX);
 			return filter(e -> predicate.test(e, index.incrementAndGet()));
@@ -423,8 +420,7 @@ public interface TransformableWrappedStream<T, S extends TransformableWrappedStr
 	}
 
 	/**
-	 * 扩散流操作，可能影响流元素个数，将原有流元素执行mapper操作，返回多个流所有元素组成的流，操作带下标，并行流时下标永远为-1
+	 * 扩散流操作，可能影响流元素个数，将原有流元素执行mapper操作，返回多个流所有元素组成的流，操作带下标
-	 * 这是一个无状态中间操作
 	 *
 	 * @param mapper 操作，返回流
 	 * @param <R>    拆分后流的元素类型
@@ -433,7 +429,10 @@ public interface TransformableWrappedStream<T, S extends TransformableWrappedStr
 	default <R> EasyStream<R> flatMapIdx(final BiFunction<? super T, Integer, ? extends Stream<? extends R>> mapper) {
 		Objects.requireNonNull(mapper);
 		if (isParallel()) {
-			return flatMap(e -> mapper.apply(e, NOT_FOUND_ELEMENT_INDEX));
+			final Map<Integer, T> idxMap = easyStream().toIdxMap();
+			return EasyStream.of(idxMap.entrySet())
+					.parallel(isParallel())
+					.flatMap(e -> mapper.apply(e.getValue(), e.getKey()));
 		} else {
 			final MutableInt index = new MutableInt(NOT_FOUND_ELEMENT_INDEX);
 			return flatMap(e -> mapper.apply(e, index.incrementAndGet()));
@@ -534,8 +533,7 @@ public interface TransformableWrappedStream<T, S extends TransformableWrappedStr
 	}
 
 	/**
-	 * 返回与指定函数将元素作为参数执行的结果组成的流，操作带下标，并行流时下标永远为-1
+	 * 返回与指定函数将元素作为参数执行的结果组成的流，操作带下标
-	 * 这是一个无状态中间操作
 	 *
 	 * @param mapper 指定的函数
 	 * @param <R>    函数执行后返回的类型
@@ -544,7 +542,10 @@ public interface TransformableWrappedStream<T, S extends TransformableWrappedStr
 	default <R> EasyStream<R> mapIdx(final BiFunction<? super T, Integer, ? extends R> mapper) {
 		Objects.requireNonNull(mapper);
 		if (isParallel()) {
-			return map(e -> mapper.apply(e, NOT_FOUND_ELEMENT_INDEX));
+			final Map<Integer, T> idxMap = easyStream().toIdxMap();
+			return EasyStream.of(idxMap.entrySet())
+					.parallel(isParallel())
+					.map(e -> mapper.apply(e.getValue(), e.getKey()));
 		} else {
 			final MutableInt index = new MutableInt(NOT_FOUND_ELEMENT_INDEX);
 			return map(e -> mapper.apply(e, index.incrementAndGet()));

hutool-core/src/main/java/cn/hutool/core/stream/WrappedStream.java

@@ -25,7 +25,7 @@ import java.util.stream.*;
 public interface WrappedStream<T, S extends WrappedStream<T, S>> extends Stream<T>, Iterable<T> {
 
 	/**
-	 * 代表不存在的下标, 一般用于并行流的下标, 或者未找到元素时的下标
+	 * 代表不存在的下标, 或者未找到元素时的下标
 	 */
 	int NOT_FOUND_ELEMENT_INDEX = -1;
 
@@ -587,4 +587,28 @@ public interface WrappedStream<T, S extends WrappedStream<T, S>> extends Stream<
 	@Override
 	String toString();
 
+	/**
+	 * 转换为EasyStream
+	 *
+	 * @return 转换后的EasyStream
+	 */
+	@SuppressWarnings("unchecked")
+	default EasyStream<T> easyStream() {
+		if (this instanceof EasyStream) {
+			return (EasyStream<T>) this;
+		} else if (this instanceof Iterator) {
+			return (EasyStream<T>) EasyStream.of((Iterator<T>) this);
+		} else {
+			return EasyStream.of(collect(Collectors.toList()));
+		}
+	}
+
+	/**
+	 * 转换为子类实现
+	 *
+	 * @param stream 流
+	 * @return 子类实现
+	 */
+	S transform(Stream<T> stream);
+
 }

hutool-core/src/test/java/cn/hutool/core/stream/AbstractEnhancedWrappedStreamTest.java

@@ -181,6 +181,7 @@ public class AbstractEnhancedWrappedStreamTest {
 		final List<Integer> list = asList(1, 2, 3);
 		final Map<Boolean, List<Integer>> map = new HashMap<Boolean, List<Integer>>() {
 			private static final long serialVersionUID = 1L;
+
 			{
 				put(Boolean.TRUE, singletonList(2));
 				put(Boolean.FALSE, asList(1, 3));
@@ -295,14 +296,8 @@ public class AbstractEnhancedWrappedStreamTest {
 		Assert.assertEquals(asList(1, 2, 3), elements);
 		Assert.assertEquals(asList(0, 1, 2), indexes);
 
-		final Set<Integer> elements2 = new HashSet<>();
+		wrap("one", "two", "three", "four").parallel().filter(e -> e.length() == 4)
-		final Set<Integer> indexes2 = new HashSet<>();
+				.peekIdx((e, i) -> Assert.assertEquals("four:0", e + ":" + i)).exec();
-		wrap(1, 2, null).parallel().peekIdx((t, i) -> {
-			elements2.add(t);
-			indexes2.add(i);
-		}).exec();
-		Assert.assertEquals(new HashSet<>(asList(1, null, 2)), elements2);
-		Assert.assertEquals(new HashSet<>(asList(-1, -1, -1)), indexes2);
 	}
 
 	@Test
@@ -630,11 +625,13 @@ public class AbstractEnhancedWrappedStreamTest {
 	public void testToEntries() {
 		final Map<Integer, Integer> expect = new HashMap<Integer, Integer>() {
 			private static final long serialVersionUID = 1L;
+
 			{
-			put(1, 1);
+				put(1, 1);
-			put(2, 2);
+				put(2, 2);
-			put(3, 3);
+				put(3, 3);
-		}};
+			}
+		};
 		Map<Integer, Integer> map = EasyStream.of(1, 2, 3)
 				.toEntries(Function.identity(), Function.identity())
 				.toMap();
@@ -709,6 +706,18 @@ public class AbstractEnhancedWrappedStreamTest {
 			return new Wrapper<>(source);
 		}
 
+		/**
+		 * 转换为子类实现
+		 *
+		 * @param stream 流
+		 * @return 子类实现
+		 */
+		@Override
+		public Wrapper<T> transform(final Stream<T> stream) {
+			this.stream = stream;
+			return this;
+		}
+
 	}
 
 	@Setter

hutool-core/src/test/java/cn/hutool/core/stream/EasyStreamTest.java

@@ -9,6 +9,7 @@ import org.junit.Assert;
 import org.junit.Test;
 
 import java.util.*;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -142,8 +143,9 @@ public class EasyStreamTest {
 		final List<String> list = Arrays.asList("dromara", "hutool", "sweet");
 		final List<String> mapIndex = EasyStream.of(list).mapIdx((e, i) -> i + 1 + "." + e).toList();
 		Assert.assertEquals(Arrays.asList("1.dromara", "2.hutool", "3.sweet"), mapIndex);
-		// 并行流时为-1
+		// 并行流时正常
-		Assert.assertEquals(Arrays.asList(-1, -1, -1), EasyStream.of(1, 2, 3).parallel().mapIdx((e, i) -> i).toList());
+		Assert.assertEquals(Arrays.asList("1.dromara", "2.hutool", "3.sweet"),
+				EasyStream.of("dromara", "hutool", "sweet").parallel().mapIdx((e, i) -> i + 1 + "." + e).toList());
 	}
 
 	@Test
@@ -192,8 +194,10 @@ public class EasyStreamTest {
 		final EasyStream.Builder<String> builder = EasyStream.builder();
 		EasyStream.of(list).forEachIdx((e, i) -> builder.accept(i + 1 + "." + e));
 		Assert.assertEquals(Arrays.asList("1.dromara", "2.hutool", "3.sweet"), builder.build().toList());
-		// 并行流时为-1
+		// 并行流时正常
-		EasyStream.of(1, 2, 3).parallel().forEachIdx((e, i) -> Assert.assertEquals(-1, (Object) i));
+		final AtomicInteger total = new AtomicInteger(0);
+		EasyStream.of("dromara", "hutool", "sweet").parallel().forEachIdx((e, i) -> total.addAndGet(i));
+		Assert.assertEquals(3, total.get());
 	}
 
 	@Test
@@ -205,7 +209,7 @@ public class EasyStreamTest {
 
 		final EasyStream.Builder<String> streamBuilder = EasyStream.builder();
 		EasyStream.of(list).parallel().forEachOrderedIdx((e, i) -> streamBuilder.accept(i + 1 + "." + e));
-		Assert.assertEquals(Arrays.asList("0.dromara", "0.hutool", "0.sweet"), streamBuilder.build().toList());
+		Assert.assertEquals(Arrays.asList("1.dromara", "2.hutool", "3.sweet"), streamBuilder.build().toList());
 
 	}
 
@@ -214,8 +218,10 @@ public class EasyStreamTest {
 		final List<String> list = Arrays.asList("dromara", "hutool", "sweet");
 		final List<String> mapIndex = EasyStream.of(list).flatMapIdx((e, i) -> EasyStream.of(i + 1 + "." + e)).toList();
 		Assert.assertEquals(Arrays.asList("1.dromara", "2.hutool", "3.sweet"), mapIndex);
-		// 并行流时为-1
+		// 并行流时正常
-		Assert.assertEquals(Arrays.asList(-1, -1, -1), EasyStream.of(1, 2, 3).parallel().flatMapIdx((e, i) -> EasyStream.of(i)).toList());
+		Assert.assertEquals(Arrays.asList("1.dromara", "2.hutool", "3.sweet"),
+				EasyStream.of("dromara", "hutool", "sweet").parallel()
+						.flatMapIdx((e, i) -> EasyStream.of(i + 1 + "." + e)).toList());
 	}
 
 	@Test
@@ -269,8 +275,9 @@ public class EasyStreamTest {
 		final List<String> list = Arrays.asList("dromara", "hutool", "sweet");
 		final List<String> filterIndex = EasyStream.of(list).filterIdx((e, i) -> i < 2).toList();
 		Assert.assertEquals(Arrays.asList("dromara", "hutool"), filterIndex);
-		// 并行流时为-1
+		// 并行流时正常
-		Assert.assertEquals(3L, EasyStream.of(1, 2, 3).parallel().filterIdx((e, i) -> i == -1).count());
+		Assert.assertEquals(Arrays.asList("dromara", "hutool"),
+				EasyStream.of("dromara", "hutool", "sweet").parallel().filterIdx((e, i) -> i < 2).toList());
 	}
 
 	@Test
@@ -434,8 +441,6 @@ public class EasyStreamTest {
 		Consumer<Object> test = o -> {
 			final List<Student> studentTree = EasyStream
 					.of(
-							// 会过滤掉id为null的元素
-							Student.builder().name("top").build(),
 							Student.builder().id(1L).name("dromara").build(),
 							Student.builder().id(2L).name("baomidou").build(),
 							Student.builder().id(3L).name("hutool").parentId(1L).build(),