From 056eb5ded6802ce3ffd33c838dcd4a278c1682f6 Mon Sep 17 00:00:00 2001
From: VampireAchao <achao1441470436@gmail.com>
Date: Tue, 6 Sep 2022 11:18:06 +0800
Subject: [PATCH] =?UTF-8?q?CollectorUtil=20=E6=96=B0=E5=A2=9E=E4=B8=A4?=
 =?UTF-8?q?=E4=B8=AA=E5=AF=B9toMap=E7=9A=84=E9=87=8D=E8=BD=BD=EF=BC=8C?=
 =?UTF-8?q?=E5=B9=B6=E5=B0=86EasyStream=E4=B8=ADjoin=E9=87=87=E7=94=A8Coll?=
 =?UTF-8?q?ectorUtil=E4=B8=AD=E7=9A=84joining?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../cn/hutool/core/stream/CollectorUtil.java  | 32 +++++++++++++++++--
 .../cn/hutool/core/stream/EasyStream.java     |  2 +-
 2 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/hutool-core/src/main/java/cn/hutool/core/stream/CollectorUtil.java b/hutool-core/src/main/java/cn/hutool/core/stream/CollectorUtil.java
index b11d08d2f..5bceb52df 100644
--- a/hutool-core/src/main/java/cn/hutool/core/stream/CollectorUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/stream/CollectorUtil.java
@@ -148,6 +148,34 @@ public class CollectorUtil {
 		return groupingBy(classifier, Collectors.toList());
 	}
 
+
+	/**
+	 * 对null友好的 toMap 操作的 {@link Collector}实现，默认使用HashMap
+	 *
+	 * @param keyMapper   指定map中的key
+	 * @param valueMapper 指定map中的value
+	 * @param <T>         实体类型
+	 * @param <K>         map中key的类型
+	 * @param <U>         map中value的类型
+	 * @return 对null友好的 toMap 操作的 {@link Collector}实现
+	 */
+	public static <T, K, U> Collector<T, ?, Map<K, U>> toMap(final Function<? super T, ? extends K> keyMapper,
+															 final Function<? super T, ? extends U> valueMapper) {
+		return toMap(keyMapper, valueMapper, (l, r) -> r);
+	}
+
+	/**
+	 * 对null友好的 toMap 操作的 {@link Collector}实现，默认使用HashMap
+	 *
+	 * @param keyMapper 指定map中的key
+	 * @param <T>       实体类型
+	 * @param <K>       map中key的类型
+	 * @return 对null友好的 toMap 操作的 {@link Collector}实现
+	 */
+	public static <T, K> Collector<T, ?, Map<K, T>> toMap(final Function<? super T, ? extends K> keyMapper) {
+		return toMap(keyMapper, Function.identity());
+	}
+
 	/**
 	 * 对null友好的 toMap 操作的 {@link Collector}实现，默认使用HashMap
 	 *
@@ -160,8 +188,8 @@ public class CollectorUtil {
 	 * @return 对null友好的 toMap 操作的 {@link Collector}实现
 	 */
 	public static <T, K, U> Collector<T, ?, Map<K, U>> toMap(final Function<? super T, ? extends K> keyMapper,
-									 final Function<? super T, ? extends U> valueMapper,
-									 final BinaryOperator<U> mergeFunction) {
+															 final Function<? super T, ? extends U> valueMapper,
+															 final BinaryOperator<U> mergeFunction) {
 		return toMap(keyMapper, valueMapper, mergeFunction, HashMap::new);
 	}
 
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 8e2319b2d..e32d06d69 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
@@ -778,7 +778,7 @@ public class EasyStream<T> extends StreamWrapper<T, EasyStream<T>> implements St
 	public String join(final CharSequence delimiter,
 					   final CharSequence prefix,
 					   final CharSequence suffix) {
-		return map(String::valueOf).collect(Collectors.joining(delimiter, prefix, suffix));
+		return map(String::valueOf).collect(CollectorUtil.joining(delimiter, prefix, suffix, Function.identity()));
 	}
 
 	/**