Matcher.quoteReplacement解决的问题

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Note that backslashes () and dollar signs ($) in the replacement string may cause the results to be different than if it were being treated as a literal replacement string. Dollar signs may be treated as references to captured subsequences as described above, and backslashes are used to escape literal characters in the replacement string.

得知，在使用replaceAll时，如果替换的字符中包含''或者''是正则中的关键字，替换会造成混淆。
解决办法：使用Matcher.quoteReplacement(sep)转义。

classFilePathStr.replaceAll(Matcher.quoteReplacement(File.separator), '.')