new Date() vs Calendar.getInstance().getTime()

最新推荐文章于 2021-01-15 17:54:44 发布

转载最新推荐文章于 2021-01-15 17:54:44 发布 · 662 阅读

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原文链接：http://www.cnblogs.com/kakaisgood/p/11165057.html

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#开发工具

博客对比了不同时间处理方式的性能，指出直接处理长时间戳效率最高，某对象性能次之，而处理日期时间相对较慢且复杂。建议在应用中主要处理长时间戳或特定对象，仅在必要时进行日期时间计算或格式化，大量处理时可考虑用Joda Time。

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System.currentTimeMillis()

vs.

new Date()

vs.

Calendar.getInstance().getTime()

System.currentTimeMillis() is obviously the most efficient since it does not even create an object, but new Date() is really just a thin wrapper about a long, so it is not far behind. Calendar, on the other hand, is relatively slow and very complex, since it has to deal with the considerably complexity and all the oddities that are inherent to dates and times (leap years, daylight savings, timezones, etc.).

It's generally a good idea to deal only with long timestamps or Date objects within your application, and only use Calendar when you actually need to perform date/time calculations, or to format dates for displaying them to the user. If you have to do a lot of this, using Joda Time is probably a good idea, for the cleaner interface and better performance.

转载于:https://www.cnblogs.com/kakaisgood/p/11165057.html