Remove filename from a URL/Path in java

Question

How do I remove the file name from a URL or String?

String os = System.getProperty("os.name").toLowerCase();
        String nativeDir = Game.class.getProtectionDomain().getCodeSource().getLocation().getFile().toString();

        //Remove the <name>.jar from the string
        if(nativeDir.endsWith(".jar"))
            nativeDir = nativeDir.substring(0, nativeDir.lastIndexOf("/"));

        //Load the right native files
        for(File f : (new File(nativeDir + File.separator + "lib" + File.separator + "native")).listFiles()){
            if(f.isDirectory() && os.contains(f.getName().toLowerCase())){
                System.setProperty("org.lwjgl.librarypath", f.getAbsolutePath()); break;
            }
        }

That's what I have right now, and it work. From what I know, because I use "/" it will only work for windows. I want to make it platform independent

Antilles

#8075873 – Mizzle

This / is not windows. ` \ ` is! – Gawk

Answer 1

Consider using org.apache.commons.io.FilenameUtils

You can extract the base path, file name, extensions etc with any flavor of file separator:

String url = "C:\\windows\\system32\\cmd.exe";

String baseUrl = FilenameUtils.getPath(url);
String myFile = FilenameUtils.getBaseName(url)
                + "." + FilenameUtils.getExtension(url);

System.out.println(baseUrl);
System.out.println(myFile);

Gives,

windows\system32\
cmd.exe

With url; String url = "C:/windows/system32/cmd.exe";

It would give;

windows/system32/
cmd.exe

Tommyetommyrot

I don't have FilenameUtils I can't import org.apache.commons.io.FilenameUtils. – Antilles

@yemto can't import would be "not supposed to" or "don't know what lib has it"? – Tommyetommyrot

@PopoFido oh, I don't like to use library's, especially for something that should be this simple. – Antilles

What about the drive letter? – Gardening

Answer 2

By utilizing java.nio.file; (afaik introduced after J2SE 1.7) this simply solved my problem:

Path path = Paths.get(fileNameWithFullPath);
String directory = path.getParent().toString();

Hagiography

Doesn't work well for HTTP URLs, which wasn't specifically mentioned in the question, but might be of interest to some browsing these answers. – Dariusdarjeeling

Answer 3

You are using File.separator in another line. Why not using it also for your lastIndexOf()?

nativeDir = nativeDir.substring(0, nativeDir.lastIndexOf(File.separator));

Orthodontia

Because It returns the wrong thing for my system. But it don't seam to care if it becomes C:\something\something\something/something – Antilles

The File.separator is returning the file separator dependent to your system. So on Windows you will get "\" while on Unix you get "/". That's why you should use the File.separator. – Orthodontia

Game.class.getProtectionDomain().getCodeSource().getLocation().getFile().toString() returns D:/Dropbox/NetBeansProjects/ while System.out.println(File.separator) returns \ so that's wrong. I have windows 7 64bit – Antilles

Well if that method always returns "/" you might want to perform a replacement first to ensure the same state in any case. String.replace() might help – Orthodontia

Notice that in order to get the filename, expression should be something like nativeDir.substring(nativeDir.lastIndexOf(File.separator) + 1) (so the substring from the separator, to the end). – Badtempered

Answer 4

File file = new File(path);
String pathWithoutFileName = file.getParent();

where path could be "C:\Users\userName\Desktop\file.txt"

Missy

Answer 5

The standard library can handle this as of Java 7

Path pathOnly;

if (file.getNameCount() > 0) {
  pathOnly = file.subpath(0, file.getNameCount() - 1);
} else {
  pathOnly = file;
}

fileFunction.accept(pathOnly, file.getFileName());

Dispread

path.getNameCount() documentation says: "the number of elements in the path, or 0 if this path only represents a root component" This could cause issues... – Hypnotism

Answer 6

Kotlin solution:

val file = File( "/folder1/folder2/folder3/readme.txt")
val pathOnly = file.absolutePath.substringBeforeLast( File.separator )
println( pathOnly )

produces this result:

/folder1/folder2/folder3

Akerley

Answer 7

Instead of "/", use File.separator. It is either / or \, depending on the platform. If this is not solving your issue, then use FileSystem.getSeparator(): you can pass different filesystems, instead of the default.

Divestiture

I would. But File.separator return a "\" while nativeDir uses "/" – Antilles

Then shouldn't something like this work? if(nativeDir.endsWith(".jar")){ int index = Math.max(nativeDir.lastIndexOf("/"), nativeDir.lastIndexOf("\\")); nativeDir = nativeDir.substring(0, index); } – Antilles

Added more info. That should resolve the difference with native dir. – Divestiture

Answer 8

I solve this problem using regex.

For windows:

String path = "";
String filename = "d:\\folder1\\subfolder11\\file.ext";
String regEx4Win = "\\\\(?=[^\\\\]+$)";
String[] tokens = filename.split(regEx4Win);
if (tokens.length > 0)
   path = tokens[0]; // path -> d:\folder1\subfolder11

Earful

Answer 9

Please try below code:

file.getPath().replace(file.getName(), "");

Couvade

Breaks if any directory has the same name as the target file. Since files without an extension are fine from an OS point of view, this may lead to something like: C:\A\B\C\B being changed to C:\A\\C, so you have unintentionally lost a directory. – Noodlehead