How to find how much disk space is left using Java?

Have a look at the File class documentation. This is one of the new features in 1.6.

These new methods also include:

• public long getTotalSpace()
• public long getFreeSpace()
• public long getUsableSpace()

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If you're still using 1.5 then you can use the Apache Commons IO library and its FileSystem class

in checking the diskspace using java you have the following method in java.io File class

• getTotalSpace()
• getFreeSpace()

which will definitely help you in getting the required information. For example you can refer to http://javatutorialhq.com/java/example-source-code/io/file/check-disk-space-java/ which gives a concrete example in using these methods.

Use CommonsIO and FilesystemUtils:

https://commons.apache.org/proper/commons-io/javadocs/api-2.5/org/apache/commons/io/FileSystemUtils.html#freeSpaceKb()

e.g.

FileSystemUtils.freeSpaceKb("/"); 

or built into the JDK:

http://java.sun.com/javase/6/docs/api/java/io/File.html#getFreeSpace()

new File("/").getFreeSpace();

Java 1.7 has a slightly different API, free space can be queried through the FileStore class through the getTotalSpace(), getUnallocatedSpace() and getUsableSpace() methods.

NumberFormat nf = NumberFormat.getNumberInstance();
for (Path root : FileSystems.getDefault().getRootDirectories()) {

    System.out.print(root + ": ");
    try {
        FileStore store = Files.getFileStore(root);
        System.out.println("available=" + nf.format(store.getUsableSpace())
                            + ", total=" + nf.format(store.getTotalSpace()));
    } catch (IOException e) {
        System.out.println("error querying space: " + e.toString());
    }
}

The advantage of this API is that you get meaningful exceptions back when querying disk space fails.