From 27142127b40bc03c96446bde99ff4645b2241b5b Mon Sep 17 00:00:00 2001
From: gqh <guqihao@terminus.io>
Date: Sat, 19 Apr 2025 23:48:12 +0800
Subject: [PATCH 1/3] =?UTF-8?q?feat:=20=E9=87=8D=E8=BD=BDsubtractToList?=
 =?UTF-8?q?=E6=96=B9=E6=B3=95=EF=BC=8C=E6=8F=90=E4=BE=9BisLinked=E9=80=89?=
 =?UTF-8?q?=E9=A1=B9?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../cn/hutool/core/collection/CollUtil.java   |  43 ++-
 .../hutool/core/collection/CollUtilTest.java  | 355 ++++++++++++++++++
 2 files changed, 394 insertions(+), 4 deletions(-)

diff --git a/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java b/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java
index fe03757c6..0fc4adbf8 100755
--- a/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java
@@ -395,22 +395,57 @@ public class CollUtil {
 	 * @since 5.3.5
 	 */
 	public static <T> List<T> subtractToList(Collection<T> coll1, Collection<T> coll2) {
+		return subtractToList(coll1, coll2, true);
+	}
 
+	/**
+	 * 计算集合的单差集，即只返回【集合1】中有，但是【集合2】中没有的元素
+	 * 只要【集合1】中的某个元素在【集合2】中存在（equals和hashcode），就会被排除
+	 *
+	 * <pre>
+	 * 示例：
+	 * 1. subtractToList([null, null, null, null], [null, null]) → []
+	 * 2. subtractToList([null, null, null, null], [null, null, "c"]) → []
+	 * 3. subtractToList(["a", "b", "c"], ["a", "b", "c"]) → []
+	 * 4. subtractToList([], ["a", "b", "c"]) → []
+	 * 5. subtractToList(["a", "b", "c"], []) → ["a", "b", "c"]
+	 * 6. subtractToList(["a", "a", "b", "b", "c", "c", "d"], ["b", "c"]) → ["a", "a", "d"]
+	 * 7. subtractToList(["a", null, "b"], ["a", "c"]) → [null, "b"]
+	 * 8. subtractToList(["a", "b", "c"], ["d", "e", "f"]) → ["a", "b", "c"]
+	 * 9. subtractToList(["a", "a", "b", "b", "c"], ["d", "e", "f"]) → ["a", "a", "b", "b", "c"]
+	 * </pre>
+	 *
+	 * @param coll1    集合1，需要计算差集的源集合
+	 * @param coll2    集合2，需要从集合1中排除的元素所在集合
+	 * @param isLinked 返回的集合类型是否是LinkedList，{@code true}返回{@link LinkedList}，{@code false}返回{@link ArrayList}
+	 * @param <T>      元素类型
+	 * @return 单差集结果。当【集合1】为空时返回空列表；当【集合2】为空时返回集合1的拷贝；否则返回【集合1】中排除【集合2】中所有元素后的结果
+	 */
+	public static <T> List<T> subtractToList(Collection<T> coll1, Collection<T> coll2, boolean isLinked) {
 		if (isEmpty(coll1)) {
 			return ListUtil.empty();
 		}
+
 		if (isEmpty(coll2)) {
-			return ListUtil.list(true, coll1);
+			return ListUtil.list(isLinked, coll1);
 		}
 
-		//将被交数用链表储存，防止因为频繁扩容影响性能
-		final List<T> result = new LinkedList<>();
+		/*
+			返回的集合最大不会超过 coll1.size
+		 	所以这里创建 ArrayList 时 initialCapacity 给的是 coll1.size
+		 	这样做可以避免频繁扩容
+		 */
+		final List<T> result = isLinked
+			? new LinkedList<>()
+			: new ArrayList<>(coll1.size());
+
 		Set<T> set = new HashSet<>(coll2);
 		for (T t : coll1) {
-			if (false == set.contains(t)) {
+			if (!set.contains(t)) {
 				result.add(t);
 			}
 		}
+
 		return result;
 	}
 
diff --git a/hutool-core/src/test/java/cn/hutool/core/collection/CollUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/collection/CollUtilTest.java
index de32a7829..5615a97aa 100755
--- a/hutool-core/src/test/java/cn/hutool/core/collection/CollUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/collection/CollUtilTest.java
@@ -845,6 +845,361 @@ public class CollUtilTest {
 		assertEquals(1L, (long) result.get(0));
 	}
 
+	@Test
+	public void subtractToListAllNullTest() {
+		final List<String> list1 = new ArrayList<>();
+		list1.add(null);
+		list1.add(null);
+		list1.add(null);
+		list1.add(null);
+
+		final List<String> list2 = new ArrayList<>();
+		list2.add(null);
+		list2.add(null);
+
+		final List<String> result1 = CollUtil.subtractToList(list1, list2);
+		assertTrue(result1.isEmpty());
+		assertNotSame(result1, list1);
+
+		list2.add("c");
+		final List<String> result2 = CollUtil.subtractToList(list1, list2);
+		assertTrue(result2.isEmpty());
+		assertNotSame(result2, list1);
+	}
+
+	@Test
+	public void subtractToListEmptyTest() {
+		// 测试第一个集合为空的情况
+		final List<String> list1 = Collections.emptyList();
+		final List<String> list2 = Arrays.asList("a", "b", "c");
+
+		// 第一个集合为空时应返回空列表
+		final List<String> result1 = CollUtil.subtractToList(list1, list2);
+		assertTrue(result1.isEmpty());
+
+		// 测试第二个集合为空的情况
+		final List<String> list3 = Arrays.asList("a", "b", "c");
+		final List<String> list4 = Collections.emptyList();
+
+		// 第二个集合为空时应返回第一个集合的拷贝
+		final List<String> result2 = CollUtil.subtractToList(list3, list4);
+		assertEquals(3, result2.size());
+		assertEquals(list3, result2);
+		assertNotSame(list3, result2);
+	}
+
+	@Test
+	public void subtractToListDuplicateTest() {
+		// 测试第一个集合中有重复元素的情况
+		final List<String> list1 = Arrays.asList("a", "a", "b", "b", "c", "c", "d");
+		final List<String> list2 = Arrays.asList("b", "c");
+
+		// 应该返回所有不在第二个集合中的元素，包括重复的
+		final List<String> result = CollUtil.subtractToList(list1, list2);
+		assertEquals(3, result.size());
+		assertEquals("a", result.get(0));
+		assertEquals("a", result.get(1));
+		assertEquals("d", result.get(2));
+	}
+
+	@Test
+	public void subtractToListNoCommonElementsTest() {
+		// 测试集合1和集合2不包含相同元素的情况
+		final List<String> list1 = Arrays.asList("a", "b", "c");
+		final List<String> list2 = Arrays.asList("d", "e", "f");
+		
+		// 期望结果：返回集合1的完整拷贝
+		final List<String> result = CollUtil.subtractToList(list1, list2);
+		assertEquals(3, result.size());
+		assertEquals("a", result.get(0));
+		assertEquals("b", result.get(1));
+		assertEquals("c", result.get(2));
+		assertEquals(list1, result);
+		assertNotSame(list1, result); // 确保返回的是拷贝而不是原始引用
+		
+		// 测试集合1中有重复元素的情况
+		final List<String> list3 = Arrays.asList("a", "a", "b", "b", "c");
+		final List<String> list4 = Arrays.asList("d", "e", "f");
+		
+		// 期望结果：返回集合1的完整拷贝，包括重复元素
+		final List<String> result2 = CollUtil.subtractToList(list3, list4);
+		assertEquals(5, result2.size());
+		assertEquals("a", result2.get(0));
+		assertEquals("a", result2.get(1));
+		assertEquals("b", result2.get(2));
+		assertEquals("b", result2.get(3));
+		assertEquals("c", result2.get(4));
+		assertEquals(list3, result2);
+		assertNotSame(list3, result2);
+		
+		// 测试不同类型的元素但确保两个集合的泛型类型一致
+		final List<Integer> list5 = Arrays.asList(1, 2, 3);
+		final List<Integer> list6 = Arrays.asList(4, 5, 6);
+		
+		// 期望结果：返回集合1的完整拷贝
+		final List<Integer> result3 = CollUtil.subtractToList(list5, list6);
+		assertEquals(3, result3.size());
+		assertEquals(Integer.valueOf(1), result3.get(0));
+		assertEquals(Integer.valueOf(2), result3.get(1));
+		assertEquals(Integer.valueOf(3), result3.get(2));
+		assertEquals(list5, result3);
+		assertNotSame(list5, result3);
+	}
+
+	@Test
+	public void subtractToListWithLinkedTest() {
+		// 测试指定返回LinkedList的情况
+		final List<Integer> list1 = Arrays.asList(1, 2, 3, 4, 5);
+		final List<Integer> list2 = Arrays.asList(2, 4);
+
+		// 使用LinkedList
+		final List<Integer> result1 = CollUtil.subtractToList(list1, list2, true);
+		assertInstanceOf(LinkedList.class, result1);
+		assertEquals(3, result1.size());
+		assertEquals(Arrays.asList(1, 3, 5), result1);
+
+		// 使用ArrayList
+		final List<Integer> result2 = CollUtil.subtractToList(list1, list2, false);
+		assertInstanceOf(ArrayList.class, result2);
+		assertEquals(3, result2.size());
+		assertEquals(Arrays.asList(1, 3, 5), result2);
+	}
+
+	@Test
+	public void subtractToListWithNullElementsTest() {
+		// 测试包含null元素的情况
+		final List<String> list1 = new ArrayList<>();
+		list1.add("a");
+		list1.add(null);
+		list1.add("b");
+
+		final List<String> list2 = Arrays.asList("a", "c");
+
+		// null元素不在list2中，应该保留
+		final List<String> result = CollUtil.subtractToList(list1, list2);
+		assertEquals(2, result.size());
+		assertNull(result.get(0));
+		assertEquals("b", result.get(1));
+	}
+
+	@Test
+	public void subtractToListLargeCollectionTest() {
+		// 测试大集合性能
+		final int size = 10000;
+		final List<Integer> list1 = new ArrayList<>(size);
+		final List<Integer> list2 = new ArrayList<>(size / 2);
+
+		// 构建测试数据，list1 size为 10000，元素为 [0, 9999]
+		for (int i = 0; i < size; i++) {
+			list1.add(i);
+		}
+
+		// list2 size 为 5000，元素为 0, 2, 4, 6, 8, ..., 9996, 9998
+		for (int i = 0; i < size / 2; i++) {
+			list2.add(i * 2); // 偶数
+		}
+
+		// 记录开始时间
+		long startTime = System.currentTimeMillis();
+
+		// 执行操作
+		final List<Integer> result = CollUtil.subtractToList(list1, list2);
+
+		// 记录结束时间
+		long endTime = System.currentTimeMillis();
+
+		// 验证结果 - 应该只包含奇数
+		assertEquals(size / 2, result.size());
+		for (Integer num : result) {
+			assertEquals(1, num % 2);
+		}
+
+		// 输出性能指标
+		System.out.println("Large collection subtractToList took: " + (endTime - startTime) + "ms for " + size + " elements");
+	}
+
+	@Test
+	public void subtractToListPerformanceComparisonTest() {
+		// 比较不同实现方式的性能
+		final int list1Size = 100000, list2Size = 1000;
+		final List<Integer> list1 = new ArrayList<>(list1Size);
+		final List<Integer> list2 = new ArrayList<>(list2Size);
+
+		// 构建测试数据，list1 size 为 100000
+		// 元素为 [0, 99999]
+		for (int i = 0; i < list1Size; i++) {
+			list1.add(i);
+		}
+
+		// [0, 9999]
+		for (int i = 0; i < list2Size; i++) {
+			list2.add(i);
+		}
+
+		// 测试LinkedList性能
+		long startTime1 = System.currentTimeMillis();
+		final List<Integer> result1 = CollUtil.subtractToList(list1, list2, true);
+		long endTime1 = System.currentTimeMillis();
+		long linkedListTime = endTime1 - startTime1;
+
+		// 测试ArrayList性能
+		long startTime2 = System.currentTimeMillis();
+		final List<Integer> result2 = CollUtil.subtractToList(list1, list2, false);
+		long endTime2 = System.currentTimeMillis();
+		long arrayListTime = endTime2 - startTime2;
+
+		// 验证结果相同
+		assertEquals(result1.size(), result2.size());
+		assertEquals(list1Size - list2Size, result1.size());
+
+		// 输出性能比较
+		System.out.println("subtractToList performance comparison for " + list1Size + " elements:");
+		System.out.println("LinkedList implementation: " + linkedListTime + "ms");
+		System.out.println("ArrayList implementation: " + arrayListTime + "ms");
+	}
+
+	@Test
+	public void subtractToListPreservesOrderTest() {
+		// 测试确保保留原始集合的顺序
+		final List<String> list1 = Arrays.asList("c", "a", "d", "b", "e");
+		final List<String> list2 = Arrays.asList("a", "e");
+
+		// 减去后应该保持原顺序：c, d, b
+		final List<String> result = CollUtil.subtractToList(list1, list2);
+		assertEquals(3, result.size());
+		assertEquals("c", result.get(0));
+		assertEquals("d", result.get(1));
+		assertEquals("b", result.get(2));
+	}
+
+	@Test
+	public void subtractToListTypeTest() {
+		// 测试默认返回LinkedList的特性（旧版本特性）
+		final List<Integer> list1 = Arrays.asList(1, 2, 3, 4, 5);
+		final List<Integer> list2 = Arrays.asList(2, 4);
+
+		// 不指定类型时，旧版本默认使用LinkedList
+		final List<Integer> result = CollUtil.subtractToList(list1, list2);
+		assertInstanceOf(LinkedList.class, result);
+		assertEquals(3, result.size());
+		assertEquals(Arrays.asList(1, 3, 5), result);
+	}
+
+	@Test
+	public void subtractToListNullElementsComparisonTest() {
+		// 测试对null元素处理的一致性
+		final ArrayList<String> list1 = new ArrayList<>();
+		list1.add(null);
+		list1.add("a");
+		list1.add(null);
+		list1.add("b");
+
+		final ArrayList<String> list2 = new ArrayList<>();
+		list2.add("a");
+
+		// 默认调用（旧版行为）
+		final List<String> result1 = CollUtil.subtractToList(list1, list2);
+		// 指定LinkedList（模拟旧版）
+		final List<String> result2 = CollUtil.subtractToList(list1, list2, true);
+		// 指定ArrayList（新版特性）
+		final List<String> result3 = CollUtil.subtractToList(list1, list2, false);
+
+		// 验证三种结果一致, 都应该是 [null, null, "b"]
+		assertEquals(3, result1.size());
+		assertEquals(3, result2.size());
+		assertEquals(3, result3.size());
+
+		// 都应该包含null元素和 "b"
+		assertTrue(result1.contains(null));
+		assertTrue(result1.contains("b"));
+		assertFalse(result1.contains("a"));
+
+		// 旧版实现和新版保持空元素顺序一致性
+		assertNull(result1.get(0));
+		assertNull(result1.get(1));
+		assertEquals("b", result1.get(2));
+
+		// 结果应该相同
+		assertEquals(result1, result2);
+		assertEquals(result1, result3);
+		assertEquals(result1.toString(), result3.toString());
+	}
+
+	@Test
+	public void subtractToListWithCustomObjectsTest() {
+		// 测试自定义对象的情况
+		final Person p1 = new Person("张三", 20, "male", 1);
+		final Person p2 = new Person("李四", 21, "female", 2);
+		final Person p3 = new Person("王五", 22, "male", 3);
+		final Person p4 = new Person("赵六", 23, "female", 4);
+
+		final List<Person> list1 = Arrays.asList(p1, p2, p3, p4);
+		final List<Person> list2 = Arrays.asList(p2, p4);
+
+		// 减去后应该只剩下p1和p3
+		final List<Person> result = CollUtil.subtractToList(list1, list2);
+		assertEquals(2, result.size());
+		assertEquals("张三", result.get(0).getName());
+		assertEquals(20, result.get(0).getAge());
+		assertEquals("male", result.get(0).getGender());
+		assertEquals(1, result.get(0).getId());
+
+		assertEquals("王五", result.get(1).getName());
+		assertEquals(22, result.get(1).getAge());
+		assertEquals("male", result.get(1).getGender());
+		assertEquals(3, result.get(1).getId());
+	}
+
+	@Test
+	public void subtractToListSameObjectsTest() {
+		// 测试两个集合有完全相同对象的情况
+		final List<String> list1 = Arrays.asList("a", "b", "c");
+		final List<String> list2 = Arrays.asList("a", "b", "c");
+
+		// 减去后应该为空列表
+		final List<String> result = CollUtil.subtractToList(list1, list2);
+		assertTrue(result.isEmpty());
+
+		// 验证结果类型
+		assertInstanceOf(LinkedList.class, result);
+		assertNotSame(result, list1);
+	}
+
+	@Test
+	public void subtractToListCollectionImplementationTest() {
+		// 测试非List集合实现的情况
+		final Set<String> set1 = new HashSet<>(Arrays.asList("a", "b", "c", "d"));
+		final Set<String> set2 = new LinkedHashSet<>(Arrays.asList("b", "d"));
+
+		// 减去后应该只剩下a和c
+		final List<String> result = CollUtil.subtractToList(set1, set2);
+		assertEquals(2, result.size());
+		assertTrue(result.contains("a"));
+		assertTrue(result.contains("c"));
+
+		// 验证结果类型
+		assertInstanceOf(LinkedList.class, result);
+	}
+
+	@Test
+	public void subtractToListConsistencyTest() {
+		// 测试subtractToList与subtract方法的一致性
+		final List<String> list1 = Arrays.asList("a", "b", "c", "d", "e");
+		final List<String> list2 = Arrays.asList("b", "d");
+
+		// 使用subtract方法
+		final Collection<String> subtractResult = CollUtil.subtract(list1, list2);
+		// 使用subtractToList方法
+		final List<String> subtractToListResult = CollUtil.subtractToList(list1, list2);
+
+		// 虽然实现类型不同，但内容应该一致
+		assertEquals(new HashSet<>(subtractResult), new HashSet<>(subtractToListResult));
+		assertEquals(3, subtractToListResult.size());
+		assertTrue(subtractToListResult.contains("a"));
+		assertTrue(subtractToListResult.contains("c"));
+		assertTrue(subtractToListResult.contains("e"));
+	}
+
 	@Test
 	public void sortComparableTest() {
 		final List<String> of = ListUtil.toList("a", "c", "b");

From 9eda35076f266f38a1ae24cd5fb56de58119a790 Mon Sep 17 00:00:00 2001
From: gqh <guqihao@terminus.io>
Date: Mon, 21 Apr 2025 09:53:42 +0800
Subject: [PATCH 2/3] =?UTF-8?q?feat:=20=E6=9B=B4=E6=AD=A3Issue3705Test#wri?=
 =?UTF-8?q?teTest?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../test/java/cn/hutool/core/text/csv/Issue3705Test.java    | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/hutool-core/src/test/java/cn/hutool/core/text/csv/Issue3705Test.java b/hutool-core/src/test/java/cn/hutool/core/text/csv/Issue3705Test.java
index efe05ac34..8763f0ba8 100644
--- a/hutool-core/src/test/java/cn/hutool/core/text/csv/Issue3705Test.java
+++ b/hutool-core/src/test/java/cn/hutool/core/text/csv/Issue3705Test.java
@@ -1,6 +1,6 @@
 package cn.hutool.core.text.csv;
 
-import cn.hutool.core.io.FileUtil;
+import cn.hutool.core.util.CharUtil;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Test;
 
@@ -19,8 +19,10 @@ public class Issue3705Test {
 			csvWriter.flush();
 		}
 
+		String lineSeparator = new String(new char[]{CharUtil.CR, CharUtil.LF});
+
 		Assertions.assertEquals(
-			"\"2024-08-20 14:24:35,\"" + FileUtil.getLineSeparator() + "最后一行",
+			"\"2024-08-20 14:24:35,\"" + lineSeparator + "最后一行",
 			stringWriter.toString());
 	}
 }

From ab0f7a06191756f7d23c86da0df0948db6b8cf5e Mon Sep 17 00:00:00 2001
From: gqh <guqihao@terminus.io>
Date: Mon, 21 Apr 2025 11:06:04 +0800
Subject: [PATCH 3/3] =?UTF-8?q?feat:=20=E6=9B=B4=E6=AD=A3FileUtilTest#smbP?=
 =?UTF-8?q?athTest?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 hutool-core/src/test/java/cn/hutool/core/io/FileUtilTest.java | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/hutool-core/src/test/java/cn/hutool/core/io/FileUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/io/FileUtilTest.java
index 0b1de97d1..ca998ec26 100644
--- a/hutool-core/src/test/java/cn/hutool/core/io/FileUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/io/FileUtilTest.java
@@ -7,6 +7,8 @@ import cn.hutool.core.util.CharsetUtil;
 import org.junit.jupiter.api.Assertions;
 import org.junit.jupiter.api.Disabled;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledOnOs;
+import org.junit.jupiter.api.condition.OS;
 
 import java.io.File;
 import java.nio.file.Path;
@@ -58,6 +60,7 @@ public class FileUtilTest {
 	}
 
 	@Test
+	@EnabledOnOs(OS.WINDOWS)
 	public void smbPathTest() {
 		final String smbPath = "\\\\192.168.1.1\\share\\rc-source";
 		final String parseSmbPath = FileUtil.getAbsolutePath(smbPath);