!416 CollUtil新增2个互换元素位置的静态方法

Merge pull request !416 from TanLongHui/v5-dev

hutool-core/src/main/java/cn/hutool/core/collection/CollUtil.java

@@ -2954,4 +2954,34 @@ public class CollUtil {
 
 		return IterUtil.isEqualList(list1, list2);
 	}
+
+	/**
+	 * 将指定元素交换到指定索引位置,其他元素的索引值不变
+	 * 交换会修改原List
+	 *
+	 * @param list        列表
+	 * @param element     需交换元素
+	 * @param targetIndex 目标索引
+	 */
+	public static <T> void swapIndex(List<T> list, T element, Integer targetIndex) {
+		if (isEmpty(list) || !list.contains(element)) {
+			return;
+		}
+		Collections.swap(list, list.indexOf(element), targetIndex);
+	}
+
+	/**
+	 * 将指定元素交换到指定元素位置,其他元素的索引值不变
+	 * 交换会修改原List
+	 *
+	 * @param list          列表
+	 * @param element       需交换元素
+	 * @param targetElement 目标元素
+	 */
+	public static <T> void swapElement(List<T> list, T element, T targetElement) {
+		if (isEmpty(list) || !list.contains(targetElement)) {
+			return;
+		}
+		swapIndex(list, element, list.indexOf(targetElement));
+	}
 }

hutool-core/src/test/java/cn/hutool/core/collection/CollUtilTest.java

@@ -767,9 +767,30 @@ public class CollUtilTest {
 	}
 
 	@Test
-	public void sortComparableTest(){
+	public void sortComparableTest() {
 		final List<String> of = ListUtil.toList("a", "c", "b");
 		final List<String> sort = CollUtil.sort(of, new ComparableComparator<>());
 		Assert.assertEquals("a,b,c", CollUtil.join(sort, ","));
 	}
+
+	@Test
+	public void swapIndex() {
+		List<Integer> list = Arrays.asList(7, 2, 8, 9);
+		CollUtil.swapIndex(list, 8, 1);
+		Assert.assertTrue(list.get(1) == 8);
+	}
+
+	@Test
+	public void swapElement() {
+		Map<String, String> map1 = new HashMap<>();
+		map1.put("1", "张三");
+		Map<String, String> map2 = new HashMap<>();
+		map2.put("2", "李四");
+		Map<String, String> map3 = new HashMap<>();
+		map3.put("3", "王五");
+		List<Map<String, String>> list = Arrays.asList(map1, map2, map3);
+		CollUtil.swapElement(list, map2, map3);
+		Map<String, String> map = list.get(2);
+		Assert.assertTrue(map.get("2").equals("李四"));
+	}
 }