为什么我们在.class文件的开头需要一个幻数？ [英] Why do we need a magic number in the beginning of the .class file?

问题描述

我在这里阅读了几篇关于每个java .class 文件开头的幻数 0xCAFEBABE 的帖子，想知道为什么需要 - 这个标记的目的是什么？

它还需要它吗？或者它现在只是为了向后兼容？

I read a few posts here about the magic number 0xCAFEBABE in the beginning of each java .class file and wanted to know why it is needed - what is the purpose of this marking?
Is it still needed anymore? or is it just for backwards compatibility now?

找不到答案的帖子 - 我也没有在java中看到答案 spec

Couldn't find a post that answers this - nor did I see the answer in the java spec

推荐答案

幻数基本上是文件格式的标识符。例如，JPEG始终以FFD8开头。 Java本身没有必要，它只是帮助识别文件类型。您可以在此处了解有关幻数的更多信息。

The magic number is basically an identifier for a file format. A JPEG for example always starts with FFD8. It is not necessary for Java itself, it simply helps to identify the file-type. You can read more about magic numbers here.

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