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!1226 DateUtil.format(Date date, String format)接口效率优化。

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Merge pull request !1226 from hellozrh/v5-dev
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Looly 2024-06-13 17:22:33 +00:00 committed by Gitee
commit 92869ca289
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2 changed files with 42 additions and 1 deletions
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2
hutool-core/src/main/java/cn/hutool/core/date/DateUtil.java
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@ -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, timeZone));
}
/**

41
hutool-core/src/test/java/cn/hutool/core/date/DateUtilTest.java
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@ -1183,4 +1183,45 @@ 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();
//此处先加载FastDateFormat对象，保存到FastDateFormat.CACHE中
//解决后面两个for循环中保存到FastDateFormat对象创建未时差异的问题。
FastDateFormat.getInstance("YYYY-MM-dd HH:mm:ss.SSS");
long t1 = System.currentTimeMillis();
String strTime = null;
for(int i=0; i<50000; i++){
strTime = DateUtil.format(value, "YYYY-MM-dd HH:mm:ss.SSS");
}
long t2 = System.currentTimeMillis();
for(int i=0; i<50000; i++){
strTime = FastDateFormat.getInstance("YYYY-MM-dd HH:mm:ss.SSS").format(value);
}
long t3 = System.currentTimeMillis();
long initTime = t1 - t0;
long formtTime1 = t2 - t1;
long formatTime2 = t3 - t2;
//此处仍然不明白，两个for循环实际执行format方法都一样，为什么第1个for时间大致是第2个for的3倍。
Assert.assertTrue(formtTime1 > formatTime2);
/**
* System.out.println("t1-t0="+(t1-t0));
* System.out.println("t2-t1="+(t2-t1));
* System.out.println("t3-t2="+(t3-t2));
*
* 由日志可以看出，第1个for时间大致是第2个for的3倍
*
* t1-t0=46
* t2-t1=65
* t3-t2=25
*/
}
}