java.io.FileNotFoundException on an existing file

问题

I am getting this error when I try to open a file:

java.io.FileNotFoundException: D:\Portable%20Programs\Android%20Development\workspace3\XXX-desktop\bin\World_X.fr (The system cannot find the path specified)
    at java.io.FileInputStream.open(Native Method)
    at java.io.FileInputStream.<init>(Unknown Source)
    at java.util.Scanner.<init>(Unknown Source)

The file is existing in the directory but I am still getting this error. However when I copy the same file in the Eclipse workspace Project src folder, no such Exception is returned (though this method also creates the World_X.fr file in the bin folder).

What I am actually trying to do is get the absolute location of the .jar file through this:

fileLocation = new String(Main.class.getProtectionDomain().getCodeSource().getLocation().getPath());

And then I am appending "World_X.fr" to the fileLocation string but this is not working. Please help me in this regard.

回答1:

You need to unescape the %20 to spaces. e.g.:

fileLocation = new String(
    Main.class.getProtectionDomain().getCodeSource().getLocation().getPath())
    .replaceAll("%20", " ");

回答2:

The preferred way to convert a file: URL into an actual File is this:

File file = new File(url.toURI());

This takes care of all checks and quoting/escaping.

Using getPath() instead will leave these odd bits up to you.

回答3:

Here is the solution for that , this will work only after JDK1.5 ,

try { f = new File("somePath".toURI().getPath()); } catch(Exception e) {}

回答4:

Try leaving out the %20, and use normal spaces instead. Also, you're using backslashes, in your code if you're using backslashes make sure you escape them first.

回答5:

The confirmed solution is quite old and even though it works for this particular case it is far more convenient to use URLDecoder, because %20 is only one encoded character, but in your path there can be whole lot of different encoded characters.

fileLocation = URLDecoder.decode(Main.class.getProtectionDomain().getCodeSource().getLocation().getPath(), "UTF-8");

来源：https://stackoverflow.com/questions/11565694/java-io-filenotfoundexception-on-an-existing-file

标签

java

filenotfoundexception

java-io