Why am I getting this InvalidPathException

Question

Have some problem with this code. Namely I am getting the message:

Exception in thread "main" java.nio.file.InvalidPathException: Illegal char <:> at index 2: [E:\Temp\564\324\123.txt]

public static void main(String[] args) throws Exception{
    Path sourseFile = Paths.get("E:\\Temp");
    Path[] result = searchFile(sourseFile, "123");
    for (Path path : result) {
        System.out.println(path);
    }        
}

public static Path[] searchFile (Path path, String fileName)throws Exception{

    DirectoryStream<Path> dirStream = Files.newDirectoryStream(path);
    ArrayList<Path> temp = new ArrayList<>();
    for (Path s : dirStream) {
        if (s.toFile().isDirectory()){
            temp.add(Paths.get(Arrays.toString(searchFile(s, fileName))));
        }
        else {
            if (s.toAbsolutePath().toString().contains(fileName)){
                temp.add(s.toAbsolutePath());
            }
        }
    }
    return temp.toArray(Path[]::new);
}

Full trace

Exception in thread "main" java.nio.file.InvalidPathException: Illegal char <:> at index 2: [E:\Temp\564\324\123.txt] at java.base/sun.nio.fs.WindowsPathParser.normalize(WindowsPathParser.java:182) at java.base/sun.nio.fs.WindowsPathParser.parse(WindowsPathParser.java:153) at java.base/sun.nio.fs.WindowsPathParser.parse(WindowsPathParser.java:77) at java.base/sun.nio.fs.WindowsPath.parse(WindowsPath.java:92) at java.base/sun.nio.fs.WindowsFileSystem.getPath(WindowsFileSystem.java:229) at java.base/java.nio.file.Path.of(Path.java:147) at java.base/java.nio.file.Paths.get(Paths.java:69) at s09.Task1.searchFile(Task1.java:28) at s09.Task1.searchFile(Task1.java:28) at s09.Task1.main(Task1.java:13)

Maybe helpful [file-path-windows-format-to-java-format](https://stackoverflow.com/questions/3059383/file-path-windows-format-to-java-format) — B001ᛦ, Jun 24 '19 at 11:56
Can you please provide a stack trace. Can you reduce the price to a couple of lines that fail the same way? — Dr Phil, Jun 24 '19 at 11:58
nope // not working at all. \\ works as it should in all other cases — Demid, Jun 24 '19 at 12:08
Do you have a "E" drive on the computer on which you are running the code you posted? Also, please show us the code for line 28 of file "Task1.java" (because according to the stack trace you posted, that line is throwing the `InvalidPathException`) — Abra, Jun 24 '19 at 13:00
The problem is caused by invalid result from `URL.getPath()` method on Windows. This is elegant solution which helped me: https://stackoverflow.com/a/54298796 — Tomáš Záluský, Mar 23 '21 at 16:02

score 5 · Answer 1 · answered Jun 24 '19 at 13:05

5

It appears that you're passing the string "[E:...]", including the surrounding square brackets added by Arrays.toString, to Paths.get. This then gets interpreted as a plain filename, in which the ":" character is indeed illegal.

answered Jun 24 '19 at 13:05

laszlok

2,390
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Stephen C · Answer 2 · 2019-06-24T14:14:47.203

I think that the clue is in the exception message:

   Illegal char <:> at index 2: [E:\Temp\564\324\123.txt]

Notice that it is saying that the illegal character is at index 2.

Now Java uses zero-based indexing for strings and arrays and most other things¹. So if the : character is at offset 2, then the [ character must be the first character of the pathname; i.e. the actual "pathname" is being formed from "[E:\Temp\564\324\123.txt]" including the square brackets.

That is wrong.

So where is that coming from?

 temp.add(Paths.get(Arrays.toString(searchFile(s, fileName))));

What?

You are calling Arrays.toString on some array, and expecting that to be a valid pathname. No way is that going to work. Read the javadocs for Arrays.toString().

For the record, here is a concise way to concatenate an array of strings to form a Path.

 String[] array = {"a", "b", "c"};
 Path p = Stream.of(array).map(Paths::get).reduce(Path::resolve).get();
 System.out.println(p);

^{1 - Including the offset in this exception message. I checked the source code.}

score 0 · Answer 3 · answered Jun 25 '19 at 09:57

Added some code for replace [ ]

public static void main(String[] args) throws Exception{
            Path sourseFile = Paths.get("E:\\Temp");
            Path[] result = searchFile(sourseFile, "123");
            for (Path path : result) {
                System.out.println(path);
            }
        }

        public static Path[] searchFile (Path path, String fileName)throws Exception{

            DirectoryStream<Path> dirStream = Files.newDirectoryStream(path);
            ArrayList<Path> temp = new ArrayList<>();
            for (Path s : dirStream) {
                if (s.toFile().isDirectory()){
                    **temp.add(Paths.get(Arrays.toString(searchFile(s, fileName)).replaceAll("\\[", "").replaceAll("\\]","")));**
                }
                else {
                    if (s.toAbsolutePath().toString().contains(fileName)){
                        temp.add(s.toAbsolutePath());
                    }
                }
            }
            return temp.toArray(Path[]::new);
        }

Why am I getting this InvalidPathException

3 Answers3