修复FieldsComparator比较结果不正确问题

hutool-core/src/test/java/org/dromara/hutool/core/comparator/Issue3259Test.java

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2023 looly(loolly@aliyun.com)
+ * Hutool is licensed under Mulan PSL v2.
+ * You can use this software according to the terms and conditions of the Mulan PSL v2.
+ * You may obtain a copy of Mulan PSL v2 at:
+ *          http://license.coscl.org.cn/MulanPSL2
+ * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
+ * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
+ * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
+ * See the Mulan PSL v2 for more details.
+ */
+
+package org.dromara.hutool.core.comparator;
+
+import lombok.AllArgsConstructor;
+import lombok.ToString;
+import org.dromara.hutool.core.collection.CollUtil;
+import org.dromara.hutool.core.collection.ListUtil;
+import org.dromara.hutool.core.util.RandomUtil;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Disabled;
+import org.junit.jupiter.api.Test;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class Issue3259Test {
+
+	@Test
+	public void fieldsComparatorTest() {
+		final Model x = new Model(1, 1);
+		final Model y = new Model(1, RandomUtil.randomInt(2, 100));
+
+		Assertions.assertTrue(new FieldsComparator<>(Model.class, "a", "b").compare(x, y) < 0);
+	}
+
+	@Test
+	@Disabled
+	public void sortTest() {
+		for(int i = 2; i < 5; i++) {
+			final Model x = new Model(1, 1);
+			final Model y = new Model(1, i);
+
+			List<Model> all = ListUtil.of(x, y);
+			all = CollUtil.sort(new ArrayList<>(all), new FieldsComparator<>(Model.class, "a", "b"));
+			System.out.println(all);
+		}
+	}
+
+	@AllArgsConstructor
+	@ToString
+	public static class Model {
+		public int a;
+		public int b;
+	}
+}