find a specific directory

[System_Error]

Does anyone know a way to find a file on a users system without knowing the path name, just the directory name? I know it's probably some recursive function, and if it is, could you kind of get me started on it, or point me in the right direction?

[Dillinger4]

I don't know if it would have to be recursive or not. Perhaps if the directory contained other directories.

[Dillinger4]

This might help.

 import java.io.*;

 public class DirectoryLister{
  public static void main(String[] args){

  File entry;
  if(args.length == 0){
     System.out.println("Please specify a directory for scanning");
     return;
  }else {
    entry = new File(args[0]);
  }
  if(!entry.exists()){
    System.out.println("Unable to process request " + entry.getPath() + " is nonexistent ");
    return; 
  }
 listDirectory(entry);
 }

public static void listDirectory(File entry){
  try{
   if(!entry.exists()){
      System.out.println(entry.getName() + "not Found");
  }
  if(entry.isFile()){
     System.out.println(entry.getCanonicalPath());

  }else if (entry.isDirectory()){
     System.out.println(entry.getPath());
     String[] filename  = entry.list();
      
     if(filename == null) return; 
     for(int i = 0; i < filename.length; i++){
       File item = new File(entry.getPath(), filename[i]);
     
     //   list it by a recursive call
        listDirectory(item);
     }
   }
  } catch(IOException e){System.out.print("Error:" + e);} 
 }
}

[Dillinger4]

You would have to chew through the directory structure and get a list of all the files in each nested directory ie. String[] filename = entry.list(); Then loop through the array returned and compare each string with the name of the file that you are looking for.

[System_Error]

That was pretty awesome. The only thing is, lets say I don't know the starting directory, how would I do that? I tried something like this, but it doesn't work...

   public File PathStart()
   {
	for (char dirs='a'; dirs >= 'z'; dirs++)
	{
		File path = new File(dirs + ":/");
			if (path.isDirectory())
			{
				startingPath = path;
				System.out.println(startingPath.toString());
			}
	}
	return startingPath;
   }

I was hoping I could get the root directory from this, and then use the return val as the root dir.

There's two problems with the code:
1) lol it doesn't work
2) the user could have cd drives, usb or whatever

If it makes it easier, I can explain the program I'm TRYING to make.

[System_Error]

Sorry, startingPath was a File Object declared as a global variable.

[Dillinger4]

You have the "/" backwards. It should be ":\" for windows platforms. You should also get in the habbit of writing platform independent code when the code accesses the underlying file system of the os.

[System_Error]

Ok. I changed it, but if that's not a good way to do it, how could I write code that is platform independent and starts at the root directory?

[CornedBee]

Windows has no root directory, so that's kinda hard to do. It's something really tricky, and I haven't yet seen a satisfactory solution.

[Dillinger4]

Take a look at the static members of the File class like File.separator they are pretty easy to use.

import java.io.File; 

String s = new String("C:" + File.separator);

[Dillinger4]

Would the root directory on a one dirve system just be C:\?

[CornedBee]

Yes, but how many one-drive systems are there? I mean, every computer has at least a floppy drive or a CD drive.

Then there's network shares - don't get me started...

On the other hand, there's the Windows Shell namespace, which has a single root, the desktop. The Shell namespace is what you browse through with Explorer.

I'm currently trying to write a C++ library to capture this stuff. It's ... interesting.

[Dillinger4]

Yeah you have a point.

[System_Error]

I wonder if we can somehow use this:

	String path = System.getProperty("user.dir");

Do you think this would work, or is this just gonna give the directory that the program is currently running from?

[Andy_Hollywood]

the user.dir property you mention points to the hom directory of the current tuser on linux, or the my Documents on windows, you could use this as a starting point, and step backwards through the parents untill you reach a null, thenyou'd know where your 'root' was, however as dilenger said on windows you don't have a root as such c:\ is only the root of the c drive, where as on linux everything is mapped in the one filesystem.. i don't think Java offers the granularity of the actual underlying system, instead showing them as C: D: etc..

[Andy_Hollywood]

i've had a thought, you could get a FileSystemView, this is what makes up the core of the JFileChooser, there is a method on it that is called getRoots() this returns a File[], if this does what it says on the tin it should give you a starting point for a recursive search of your file system!

[CornedBee]

It does indeed work, but only for local drives.