Java：如何从转义的 URL 中获取文件？
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Java: how to get a File from an escaped URL?
提问by SyntaxT3rr0r
I'm receiving an URL that locates a local file (the fact that I receive an URL is not in my control). The URL is escaped validly as defined in RFC2396. How can I transform this to a Java File object?
我收到了一个定位本地文件的 URL（我收到的 URL 不在我的控制范围内）。URL 按照 RFC2396 中的定义进行有效转义。如何将其转换为 Java File 对象？
Funnily enough, the URL getFile() method returns a String, not a File.
有趣的是，URL getFile() 方法返回一个字符串，而不是一个文件。
I've created a directory called "/tmp/some dir" (with a spacing character between "some" and "dir"), which is correctly located by the following URL: "file:///tmp/some%20dir" (quotes added for clarity).
我创建了一个名为“/tmp/some dir”的目录（“some”和“dir”之间有一个空格字符），它可以通过以下 URL 正确定位：“file:///tmp/some%20dir” （为清楚起见添加了引号）。
How can I convert that URL to a Java File?
如何将该 URL 转换为 Java 文件？
To give more detail about my issue, the following prints false:
为了提供有关我的问题的更多详细信息，以下打印错误：
URL url = new URL( "file:///tmp/some%20dir" );
File f = new File( url.getFile() );
System.out.println( "Does dir exist? " + f.exists() );
While the following (manually replacing "%20" with a space) prints true:
虽然以下（用空格手动替换“%20”）打印为真：
URL url = new URL( "file:///tmp/some%20dir" );
File f = new File( url.getFile().replaceAll( "%20", " " ) );
System.out.println( "Does dir exist? " + f.exists() );
Note that I'm not asking whythe first example prints false nor whythe second example using my hacky replaceAllprints true, I'm asking how to convert an escaped URL into a Java File object.
请注意，我没有问为什么第一个例子打印错误，也不为什么用我的哈克第二个例子中的replaceAll打印真实的，我问如何转换逸出的网址为Java File对象。
EDIT: thanks all, this was nearly a dupe but not exactly.
编辑：谢谢大家，这几乎是一个骗局，但不完全是。
Stupidly I was looking for a helper method inside the URL class itself.
愚蠢的是，我正在 URL 类本身中寻找一个辅助方法。
The following works as expected to get a Java File from a Java URL:
以下工作按预期从 Java URL 获取 Java 文件：
URL url = new URL( "file:///home/nonet/some%20dir" );
File f = new File( URLDecoder.decode( url.getFile(), "UTF-8" ) );
采纳答案by Cesar
URLDecoder.decode(url);//deprecated
URLDecoder.decode(url, "UTF-8"); //use this instead
See related question How do you unescape URLs in Java?
请参阅相关问题如何在 Java 中取消转义 URL？
回答by BalusC
The Fileconstructor taking an URIin combination with URL#toURI()should work:
结合 with的File构造函数URIURL#toURI()应该可以工作：
URL url = getItSomehow();
File file = new File(url.toURI());
回答by vorburger
AFAIK like this Paths.get(url.toURI()).toFile()is best, starting with Java 7. See also Converting Java file:// URL to File(...) path, platform independent, including UNC paths.
Paths.get(url.toURI()).toFile()从 Java 7 开始，这样的 AFAIK是最好的。另请参阅将 Java file:// URL 转换为 File(...) 路径，与平台无关，包括 UNC 路径。
