From aae72484f19d62c98cfb8490ccd126d7be03ce20 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E8=87=A7=E8=87=A7?= <2556450572@qq.com>
Date: Wed, 24 Aug 2022 13:16:31 +0800
Subject: [PATCH] =?UTF-8?q?=E5=AF=B9EasyStream=E4=B8=AD=E8=A1=A5=E5=85=85p?=
 =?UTF-8?q?eekIdx()=E6=96=B9=E6=B3=95,mapMulti=E9=80=82=E9=85=8D=E4=BA=8E?=
 =?UTF-8?q?=E6=9B=B4=E9=AB=98=E7=89=88=E6=9C=ACJDK?=
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---
 .../cn/hutool/core/stream/EasyStream.java     | 28 ++++++++++++++++++-
 1 file changed, 27 insertions(+), 1 deletion(-)

diff --git a/hutool-core/src/main/java/cn/hutool/core/stream/EasyStream.java b/hutool-core/src/main/java/cn/hutool/core/stream/EasyStream.java
index dbc35d1e0..cd8f71d19 100644
--- a/hutool-core/src/main/java/cn/hutool/core/stream/EasyStream.java
+++ b/hutool-core/src/main/java/cn/hutool/core/stream/EasyStream.java
@@ -25,6 +25,7 @@ import java.util.Spliterator;
 import java.util.Spliterators;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.BiConsumer;
 import java.util.function.BiFunction;
 import java.util.function.BiPredicate;
@@ -526,7 +527,7 @@ public class EasyStream<T> implements Stream<T>, Iterable<T> {
 	 * @param <R>    拆分后流的元素类型
 	 * @return 返回叠加拆分操作后的流
 	 */
-	public <R> EasyStream<R> mapMulti(final BiConsumer<? super T, ? super FastStreamBuilder<R>> mapper) {
+	public <R> EasyStream<R> mapMulti(final BiConsumer<? super T, ? super Consumer<R>> mapper) {
 		Objects.requireNonNull(mapper);
 		return flatMap(e -> {
 			final FastStreamBuilder<R> buffer = EasyStream.builder();
@@ -630,6 +631,31 @@ public class EasyStream<T> implements Stream<T>, Iterable<T> {
 		return new EasyStream<>(stream.peek(action));
 	}
 
+	/**
+	 * 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
+	 * 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
+	 * @apiNote 该方法存在的意义主要是用来调试
+	 * 当你需要查看经过操作管道某处的元素和下标，可以执行以下操作:
+	 * <pre>{@code
+	 *     .of("one", "two", "three", "four")
+	 * 				.filter(e -> e.length() > 3)
+	 * 				.peekIdx((e,i) -> System.out.println("Filtered value: " + e + " Filtered idx:" + i))
+	 * 				.map(String::toUpperCase)
+	 * 				.peekIdx((e,i) -> System.out.println("Mapped value: " + e + " Filtered idx:" + i))
+	 * 				.collect(Collectors.toList());
+	 * }</pre>
+	 */
+	public EasyStream<T> peekIdx(BiConsumer<? super T, Integer> action) {
+		Objects.requireNonNull(action);
+		if (isParallel()) {
+			return peek(e -> action.accept(e, NOT_FOUND_INDEX));
+		} else {
+			AtomicInteger index = new AtomicInteger(NOT_FOUND_INDEX);
+			return peek(e -> action.accept(e, index.incrementAndGet()));
+		}
+	}
 	/**
 	 * 返回叠加调用{@link Console#log(Object)}打印出结果的流
 	 *