获取文件的最后修改日期/时间作为本地日期/时间字符串
new File（url）.lastModified（）返回 long 等于自纪元以来的毫秒数，这是基于GMT的。
new File(url).lastModified() returns a long equal to the number of milliseconds since the epoch, which is GMT-based.
将此转换为表示系统本地的 String 的简单方法是什么？日期/时间？
What is a simple way to convert this to a String representing system-local date/time?
如果你真的需要在这里看到我的尝试，但这是一个可怕的混乱，无论如何它是错的：
If you really need to see an attempt from me here it is but it's a terrible mess and it's wrong anyway:
LocalDateTime.ofEpochSecond(new File(url).lastModified()/1000,0,ZoneOffset.UTC).atZone(ZoneId.of("UTC")).format(DateTimeFormatter.ofLocalizedDateTime(FormatStyle.LONG))
超出 LocalDateTime 我只是不知道时间API是如何工作的。
Beyond LocalDateTime I just have no idea how the time API works.
获取上次修改时间文件，您应该使用Java NIO.2 API，它直接解决您的问题：
To get the last modified time of a file, you should use Java NIO.2 API, which directly resolves your problem:
FileTime fileTime = Files.getLastModifiedTime(Paths.get(url));
System.out.println(fileTime); // will print date time in "YYYY-MM-DDThh:mm:ss[.s+]Z" format
如果要访问其他属性（如上次访问时间，创建时间），可以使用 Files.readAttributes（path，BasicFileAttributes.class）$ c读取路径的基本属性$ c>。
If you want to access other properties (like last access time, creation time), you can read the basic attributes of a path with Files.readAttributes(path, BasicFileAttributes.class).