Find free disk space using Java

There are a few method calls in java that can be utilized to get the space related information about a disk drive. These methods used to fetch the such information are declared in File class, which resides in java.io package. The details of these method call along with their use are given below:
Note: These codes will not run on online ide. Also, they will all work on Java 1.6 and above versions

1. Java.io.File.getFreeSpace(): Get total free space available in a drive
   Syntax:

   public long getFreeSpace()
   Returns the size of the partition named by this abstract pathname.
   Returns:
   The size, in bytes, of the partition or 0L if this 
   abstract pathname does not name a partition
   Throws:
   SecurityException - If a security manager has been installed and it 
   denies RuntimePermission("getFileSystemAttributes") or its 
   SecurityManager.checkRead(String) method denies read access to the file 
   named by this abstract pathname

   // Java program to get the amount of free space available on any drive
   import java.io.*;
   
   public class Test
   {
       public static void main(String[] args)
       {
           File file = new File("E:\\");
   
           double size = file.getFreeSpace() / (1024.0 * 1024 * 1024);
           System.out.printf( "%.3f GB\n", size);
       }
   }

   Output:

   18.242 GB

2. Java.io.File.getUsableSpace(): Total usable space available with a drive. Returns the number of bytes available to this virtual machine on the partition named by this abstract pathname. When possible, this method checks for write permissions and other operating system restrictions and will therefore usually provide a more accurate estimate of how much new data can actually be written than getFreeSpace().
   The returned number of available bytes is a hint, but not a guarantee, that it is possible to use most or any of these bytes. The number of unallocated bytes is most likely to be accurate immediately after this call. It is likely to be made inaccurate by any external I/O operations including those made on the system outside of this virtual machine. This method makes no guarantee that write operations to this file system will succeed.
   Syntax:

   public long getUsableSpace()
   Returns:
   The number of available bytes on the partition or 0L if the 
   abstract pathname does not name a partition. On systems where
   this information is not available, this method will be
   equivalent to a call to getFreeSpace().
   Throws:
   SecurityException - If a security manager has been installed and it 
   denies RuntimePermission("getFileSystemAttributes") or its
   SecurityManager.checkRead(String) method denies read access to the 
   file named by this abstract pathname

   import java.io.*;
   
   public class Test
   {
       public static void main(String[] args)
       {
           double size =
                 new File("C:\\").getUsableSpace() / (1024.0 * 1024 * 1024);
           System.out.printf( "%.3f GB\n", size);
       }
   }

   Output:

   62.857 GB

3. Java.io.File.getTotalSpace(): Total Capacity of a drive. The method returns the size of the partition named by this abstract pathname.

   Syntax:

   public long getTotalSpace()
   Returns: Returns:
   The size, in bytes, of the partition or 0L if this abstract pathname 
   does not name a partition
   Throws:
   SecurityException - If a security manager has been installed and it
   denies RuntimePermission("getFileSystemAttributes") or its 
   SecurityManager.checkRead(String) method denies read access to 
   the file named by this abstract pathname

   import java.io.*;
   
   public class Test
   {
       public static void main(String[] args)
       {
           double size =
                 new File("C:\\").getUsableSpace() / (1024.0 * 1024 * 1024);
           System.out.printf( "%.3f GB\n", size);
       }
   }

   Output:

   62.857 GB

Reference used: Oracle