From 29a6cba58da9a794b042e70991b83dd771ee5519 Mon Sep 17 00:00:00 2001
From: hellozrh <455741807@qq.com>
Date: Thu, 13 Jun 2024 14:44:53 +0800
Subject: [PATCH] =?UTF-8?q?DateUtil.format(Date=20date,=20String=20format)?=
 =?UTF-8?q?=E6=8E=A5=E5=8F=A3=E6=95=88=E7=8E=87=E4=BC=98=E5=8C=96=E3=80=82?=
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---
 .../java/cn/hutool/core/date/DateUtil.java    |  2 +-
 .../cn/hutool/core/date/DateUtilTest.java     | 26 +++++++++++++++++++
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java b/hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java
index 74f907252..f005c04eb 100755
--- a/hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java
+++ b/hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java
@@ -522,7 +522,7 @@ public class DateUtil extends CalendarUtil {
 		if (date instanceof DateTime) {
 			timeZone = ((DateTime) date).getTimeZone();
 		}
-		return format(date, newSimpleFormat(format, null, timeZone));
+		return format(date, FastDateFormat.getInstance(format));
 	}
 
 	/**
diff --git a/hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java b/hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java
index 974182dc4..d61eea6c6 100755
--- a/hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java
+++ b/hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java
@@ -1183,4 +1183,30 @@ public class DateUtilTest {
 		final DateTime parse = DateUtil.parse(str);
 		Assert.assertEquals("2023-12-11 10:42:04", Objects.requireNonNull(parse).toString());
 	}
+
+	@Test
+	public void formatSpeedTest(){
+		Date value = new Date();
+		long t0 = System.currentTimeMillis();
+		FastDateFormat.getInstance("YYYY-MM-dd HH:mm:ss.SSSSSS");
+		long t1 = System.currentTimeMillis();
+		String strTime = null;
+		for(int i=0; i<5000; i++){
+			strTime = DateUtil.format(value, "YYYY-MM-dd HH:mm:ss.SSSSSS");
+		}
+		System.out.println("format="+strTime);
+		long t2 = System.currentTimeMillis();
+
+		for(int i=0; i<5000; i++){
+			strTime = FastDateFormat.getInstance("YYYY-MM-dd HH:mm:ss.SSSSSS").format(value);
+		}
+		System.out.println("FastDateFormat="+strTime);
+
+		long t3 = System.currentTimeMillis();
+
+		System.out.println("t1-t0="+(t1-t0));
+		System.out.println("t2-t1="+(t2-t1));
+		System.out.println("t3-t2="+(t3-t2));
+	}
+
 }