Turns out Java has no mechanism for discovering the names of disk volumes. You can use java.io.File.listRoots() to get the root paths for multiple disks, but you can’t auto-discover their names.

Here’s a quick hack that will work on Windows. It uses Runtime.getRuntime().exec() to run “cmd /c dir “, the output of which is parsed to get the volume name.

import java.io.*; 

void setup() {
  println("Testing getVolName");

  String path="D:";
  println("Volume name for "+path+" is: "+
    "'"+getDiskVolumeName(path)+"'");
}

public static String getDiskVolumeName(String path) {
  String volname="Unknown";
  String check="Volume in drive "+path.charAt(0)+" is ";
  try  {
    Process p=Runtime.getRuntime().exec("cmd /c dir "+path);
    //p.waitFor(); 

    BufferedReader reader=new BufferedReader(
      new InputStreamReader(p.getInputStream()));
    String line=reader.readLine();
    while(line!=null) {
      if(line.indexOf(check)!=-1)
        volname=line.substring(line.indexOf(check)+check.length());

//      System.out.println(line);
      line=reader.readLine();
    }
  }
  catch(Exception e1) {
    println("Failure: "+e1.toString());
  }
  return volname;
}