In Java File I/O programming, to list all available drive partitions on computer, we can use the following code snippet:

File[] drives = File.listRoots();
if (drives != null && drives.length > 0) {
	for (File aDrive : drives) {
		System.out.println(aDrive);
	}
} 

The above code snippet would produce the following output (e.g. on Windows platform):

C:\
D:\
E:\
F:\ 

The output may vary, depending on system configuration and platform, e.g. there would be only one root partition “\” on a Linux/Unix system.

 

Getting type description of a drive:

To know which type (hard disk, CD-ROM, flash drive, etc) of a drive, we can use the method getSystemTypeDescription(File) provided by the FileSystemView class in the javax.swing.filechooser package. For example:

FileSystemView fsv = FileSystemView.getFileSystemView();
String driveType = fsv.getSystemTypeDescription(aDrive);

 

Getting total space and free space of a drive:

Since Java 1.6, we can know the total space and free space of a drive partition by using the getTotalSpace() and getFreeSpace() methods, respectively. These methods return the spaces in bytes. For example:

• On Windows:
  

  File aDrive = new File("C:");
  
  long freeSpace = aDrive.getFreeSpace();
  long totalSpace = aDrive.getTotalSpace();

   

• On Linux/Unix:
  

  File aDrive = new File("\\");
  
  long freeSpace = aDrive.getFreeSpace();
  long totalSpace = aDrive.getTotalSpace();

   

Java Listing Drivers Example Program:

The following program lists all available drive partitions with their drive letters, type descriptions, free spaces and total spaces:

package net.codejava.io;

import java.io.File;

import javax.swing.filechooser.FileSystemView;

/**
 * 
 * @author www.codejava.net
 *
 */
public class DrivesListingExample {

	public static void main(String[] args) {
		
		FileSystemView fsv = FileSystemView.getFileSystemView();
		
		File[] drives = File.listRoots();
		if (drives != null && drives.length > 0) {
			for (File aDrive : drives) {
				System.out.println("Drive Letter: " + aDrive);
				System.out.println("\tType: " + fsv.getSystemTypeDescription(aDrive));
				System.out.println("\tTotal space: " + aDrive.getTotalSpace());
				System.out.println("\tFree space: " + aDrive.getFreeSpace());
				System.out.println();
			}
		}
	}
} 

Sample output on Windows:

Drive Letter: C:\
	Type: Local Disk
	Total space: 73402363904
	Free space: 11994337280

Drive Letter: D:\
	Type: Local Disk
	Total space: 106151542272
	Free space: 84617833472

Drive Letter: E:\
	Type: Local Disk
	Total space: 106232282624
	Free space: 70415875072

Drive Letter: F:\
	Type: CD Drive
	Total space: 0
	Free space: 0

 

Sample output on Unix/Linux:

Drive Letter: /
	Type: null
	Total space: 30829133824
	Free space: 22259314688 

 

Other Java File IO Tutorials:

• How to Read and Write Text File in Java
• How to Read and Write Binary Files in Java
• Java IO - Common File and Directory Operations Examples
• Java Serialization Basic Example
• Understanding Java Externalization with Examples
• How to execute Operating System Commands in Java
• 3 ways for reading user's input from console in Java
• File change notification example with Watch Service API
• Java Scanner Tutorial and Code Examples
• How to compress files in ZIP format in Java
• How to extract ZIP file in Java