How to get free disk space in Java

In Java old days, it lacks of method to determine the free disk space on a partition. But this is changed since JDK 1.6 released, a few new methods – getTotalSpace(), getUsableSpace() and getFreeSpace(), are bundled with java.io.File to retrieve the partition or disk space detail.

Example

DiskSpaceDetail.java

package com.favtuts.io.howto;

import java.io.File;

public class DiskSpaceDetail {
    public static void main(String[] args)
    {	
    	//File file = new File("c:");        
        File file = new File("/");
    	long totalSpace = file.getTotalSpace(); //total disk space in bytes.
    	long usableSpace = file.getUsableSpace(); ///unallocated / free disk space in bytes.
    	long freeSpace = file.getFreeSpace(); //unallocated / free disk space in bytes.
    	
    	System.out.println(" === Partition Detail ===");
    	
    	System.out.println(" === bytes ===");
    	System.out.println("Total size : " + totalSpace + " bytes");
    	System.out.println("Space free : " + usableSpace + " bytes");
    	System.out.println("Space free : " + freeSpace + " bytes");
    	
    	System.out.println(" === mega bytes ===");
    	System.out.println("Total size : " + totalSpace /1024 /1024 + " mb");
    	System.out.println("Space free : " + usableSpace /1024 /1024 + " mb");
    	System.out.println("Space free : " + freeSpace /1024 /1024 + " mb");
    }
}

Output

Display the disk space detail in c: partition.

 === Partition Detail ===
 === bytes ===
Total size : 124959473664 bytes
Space free : 49257910272 bytes
Space free : 55649554432 bytes
 === mega bytes ===
Total size : 119170 mb
Space free : 46976 mb
Space free : 53071 mb

Note

Both getFreeSpace() and getUsableSpace() methods are return the same total free disk space of a given partition. But the real different is not clear, even in the java doc. Tell me if you know what’s the different in between.

Download Source Code

$ git clone https://github.com/favtuts/java-core-tutorials-examples

$ cd java-io/howto

Reference

http://download.oracle.com/javase/6/docs/api/java/io/File.html