添加 参考链接

hutool-extra/src/main/java/cn/hutool/extra/spring/SpringCronUtil.java

@@ -22,6 +22,7 @@ import java.util.concurrent.ScheduledFuture;
  *     <li>取消定时任务</li>
  *     <li>高级操作</li>
  * </ol>
+ * 参考：<a href="https://docs.spring.io/spring-framework/docs/current/reference/html/integration.html#scheduling">Spring doc</a>
  *
  * @author JC
  * @date 03/13

hutool-extra/src/test/java/cn/hutool/extra/spring/SpringCronUtilTest.java

@@ -61,7 +61,7 @@ public class SpringCronUtilTest {
 
 	/**
 	 * 高级用法
-	 * 参考：
+	 * 参考：<a href="https://docs.spring.io/spring-framework/docs/current/reference/html/integration.html#scheduling">Spring doc</a>
 	 */
 	@Test
 	public void senior() {