Detect USB Drive in Java

Question

How can I detect when a USB drive is attached to a computer in Windows, Linux, or Mac?

The only way I have seen online to do this is to iterate the drives, but I don

Answer 1

public class AutoDetect {

static File[] oldListRoot = File.listRoots();
public static void main(String[] args) {
    AutoDetect.waitForNotifying();

}

public static void waitForNotifying() {
    Thread t = new Thread(new Runnable() {
        public void run() {
            while (true) {
                try {
                    Thread.sleep(100);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                if (File.listRoots().length > oldListRoot.length) {
                    System.out.println("new drive detected");
                    oldListRoot = File.listRoots();
                    System.out.println("drive"+oldListRoot[oldListRoot.length-1]+" detected");

                } else if (File.listRoots().length < oldListRoot.length) {
    System.out.println(oldListRoot[oldListRoot.length-1]+" drive removed");

                    oldListRoot = File.listRoots();

                }

            }
        }
    });
    t.start();
}
}

Answer 2

Check out this code. To fulfill your demands, simply poll to detect the USB drive and continue when you got it.

Answer 3

Last time I checked there were no open source USB library for java and in windows. The simple hack that I used was to write a small JNI app for capturing WM_DEVICECHANGE event. Following links may help

1. http://www.codeproject.com/KB/system/DriveDetector.aspx
2. http://msdn.microsoft.com/en-us/library/aa363480(v=VS.85).aspx

In case you don't want to mess with the JNI then use any windows native library for USB with JNA ( https://github.com/twall/jna/ )

altough i would suggest using WM_DEVICECHANGE approach... because your requirement is just a notification message....

Answer 4

I created the code that works on Linux and windows check this

 import java.io.BufferedReader; 
 import java.io.File;
 import java.io.IOException;
 import java.io.InputStreamReader;

 public class Main{
 public static void main(String[] args) throws IOException{//main class
     Main m = new Main();//main method
     String os = System.getProperty("os.name").toLowerCase();//get Os name
     if(os.indexOf("win") > 0){//checking if os is *nix or windows
         //This is windows
         m.ListFiles(new File("/storage"));//do some staf for windows i am not so sure about '/storage' in windows
         //external drive will be found on 
     }else{
         //Some *nix OS
         //all *nix Os here
         m.ListFiles(new File("/media"));//if linux removable drive found on media
         //this is for Linux

     }


 }

 void ListFiles(File fls)//this is list drives methods
             throws IOException {
     while(true){//while loop


 try {
    Thread.sleep(5000);//repeate a task every 5 minutes
} catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
}
     Process p = Runtime.getRuntime().exec("ls "+fls);//executing command to get the output
     BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));//getting the output
             String line;//output line
                while((line = br.readLine()) != null){//reading the output
                 System.out.print("removable drives : "+line+"\n");//printing the output
           }
          /*You can modify the code as you wish. 
          * To check if external storage drivers pluged in or removed, compare the lenght
          * Change the time interval if you wish*/
           }

      }
 }

Answer 5

I've made a small library to detect USB storage devices on Java. It works on Windows, OSX and Linux. Take a look at: https://github.com/samuelcampos/usbdrivedetector

Answer 6

I wrote this program. At the beginning of the program, do DriverCheck.updateDriverInfo(). Then, to check to see if a usb has been plugged in or pulled out, use DriverChecker.driversChangedSinceLastUpdate() (returns boolean).

To check if a usb has been inserted, use newDriverDetected(). To check if a usb has been removed, use driverRemoved()

This pretty much checks for all disc drives from A:/ to Z:/. Half of them can't even exist, but I check for all of them anyways.

package security;

import java.io.File;

public final class DriverChecker {
    private static boolean[] drivers = new boolean[26];

    private DriverChecker() {

    }

    public static boolean checkForDrive(String dir) {
        return new File(dir).exists();
    }

    public static void updateDriverInfo() {
        for (int i = 0; i < 26; i++) {
            drivers[i] = checkForDrive((char) (i + 'A') + ":/");
        }
    }

    public static boolean newDriverDetected() {
        for (int i = 0; i < 26; i++) {
            if (!drivers[i] && checkForDrive((char) (i + 'A') + ":/")) {
                return true;
            }
        }
        return false;
    }

    public static boolean driverRemoved() {
        for (int i = 0; i < 26; i++) {
            if (drivers[i] && !checkForDrive((char) (i + 'A') + ":/")) {
                return true;
            }
        }
        return false;
    }

    public static boolean driversChangedSinceLastUpdate() {
        for (int i = 0; i < 26; i++) {
            if (drivers[i] != checkForDrive((char) (i + 'A') + ":/")) {
                return true;
            }
        }
        return false;
    }

    public static void printInfo() {
        for (int i = 0; i < 26; i++) {
            System.out.println("Driver " + (char) (i + 'A') + ":/ "
                    + (drivers[i] ? "exists" : "does not exist"));
        }
    }
}