From be0de6bab4eef856519837d4e53419fcf93c2562 Mon Sep 17 00:00:00 2001
From: xuxin <840198532@qq.com>
Date: Tue, 13 Oct 2026 11:18:54 +0800
Subject: [PATCH] =?UTF-8?q?s-day01--System=E7=B1=BB=E8=8E=B7=E5=8F=96?=
 =?UTF-8?q?=E5=BD=93=E5=89=8D=E7=B3=BB=E7=BB=9F=E6=97=B6=E5=88=BB?=
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---
 s-day01/src/com/inmind/system05/Demo15.java | 27 +++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 s-day01/src/com/inmind/system05/Demo15.java

diff --git a/s-day01/src/com/inmind/system05/Demo15.java b/s-day01/src/com/inmind/system05/Demo15.java
new file mode 100644
index 0000000..75566f8
--- /dev/null
+++ b/s-day01/src/com/inmind/system05/Demo15.java
@@ -0,0 +1,27 @@
+package com.inmind.system05;
+
+import java.util.Date;
+
+/*
+    static long currentTimeMillis() 返回当前时间（以毫秒为单位）。
+
+    作用:测试一段代码的执行效率(io流的时候,检测普通流和高效流之间的效率问题)
+ */
+public class Demo15 {
+    public static void main(String[] args) {
+        //获取当前系统毫秒值
+        long start = System.currentTimeMillis();
+        System.out.println(start);
+        for (int i = 0; i < 1000; i++) {
+            System.out.println(i);
+        }
+        //测试一段代码的执行效率
+        long end = System.currentTimeMillis();
+        System.out.println("1000次打印的时间："+(end - start));
+
+
+        Date date = new Date();
+        System.out.println(date.getTime());
+
+    }
+}