How do I get free space of a drive or volume?

By Wayan in Apache Commons, Commons IO 0 Comment

The getFreeSpaceKb(String path) method in the FileSystemUtils class can help you to calculate the free space of a drive or volume in kilobytes.

Beside using commons-io solution, you can use the File.getFreeSpace() method call provided in the Java 1.6 API. You can find an example of it in the following link: How do I get total space and free space of my disk?.

package org.kodejava.commons.io;

import org.apache.commons.io.FileSystemUtils;
import org.apache.commons.io.FileUtils;

import java.io.IOException;

public class DiskFreeSpace {
    public static void main(String[] args) {
        try {
            String path = "F:/Temp";
            long freeSpaceKB = FileSystemUtils.freeSpaceKb(path);
            long freeSpaceMB = freeSpaceKB / FileUtils.ONE_KB;
            long freeSpaceGB = freeSpaceKB / FileUtils.ONE_MB;

            System.out.println("Size of " + path + " = " + freeSpaceKB + " KB");
            System.out.println("Size of " + path + " = " + freeSpaceMB + " MB");
            System.out.println("Size of " + path + " = " + freeSpaceGB + " GB");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

An example result of the code above is:

Size of F:/Temp = 323413052 KB
Size of F:/Temp = 315833 MB
Size of F:/Temp = 308 GB

Maven Dependencies

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.14.0</version>
</dependency>

Maven Central

How do I search for files recursively using Apache Commons IO?

By Wayan in Apache Commons, Commons IO 0 Comment

This example demonstrates how we can use the FileUtils class listFiles() method to search for a file specified by their extensions. We can also define to find the file recursively deep down into the subdirectories.

package org.kodejava.commons.io;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.util.Collection;

public class SearchFileRecursive {
    public static void main(String[] args) {
        File root = new File("F:/Wayan/Kodejava/kodejava-example");

        try {
            String[] extensions = {"xml", "java", "dat"};

            // Find files within a root directory and optionally its
            // subdirectories, which match an array of extensions. When the
            // extensions are null, all files will be returned.
            //
            // This method will return matched file as java.io.File
            Collection<File> files = FileUtils.listFiles(root, extensions, true);

            for (File file : files) {
                System.out.println("File = " + file.getAbsolutePath());
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Maven Dependencies

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.14.0</version>
</dependency>

Maven Central

How do I touch a file using Apache Commons IO?

By Wayan in Apache Commons, Commons IO 0 Comment

This example demonstrates a touch command just like Unix touch command. If the file to be touched doesn’t exist, a new empty file will be created.

package org.kodejava.commons.io;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;

public class TouchFileExample {
    public static void main(String[] args) {
        try {
            File file = new File("Touch.dat");

            // Touch the file. When the file does not exist, a new file will be
            // created. If the file exists, change the file timestamp.
            FileUtils.touch(file);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Maven Dependencies

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.14.0</version>
</dependency>

Maven Central

How do I delete directory recursively?

By Wayan in Apache Commons, Commons IO 0 Comment

Using the FileUtils.deleteDirectory() from the Apache Commons IO library, we can simplify the process of deleting directory and everything below it recursively.

package org.kodejava.commons.io;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;

public class DeleteDirectory {
    public static void main(String[] args) {
        try {
            File directory = new File("F:/Temp");

            // Deletes a directory recursively. When a deletion process is failed, an
            // IOException will be thrown; that's why we catch the exception.
            FileUtils.deleteDirectory(directory);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Maven Dependencies

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.14.0</version>
</dependency>

Maven Central

How do I create a human-readable file size?

By Wayan in Apache Commons, Commons IO 0 Comment

This example demonstrates how to create a human-readable file size using the FileUtils class of the Apache Commons IO library. The byteCountToDisplaySize() method take the file size in bytes and return a human-readable display of the file size in bytes, kilobytes, megabytes, gigabytes, etc.

package org.kodejava.commons.io;

import org.apache.commons.io.FileUtils;

import java.io.File;

public class ReadableFileSize {
    public static void main(String[] args) {
        File file = new File("D:/Downloads/jdk-17_windows-x64_bin.exe");

        long size = file.length();
        String display = FileUtils.byteCountToDisplaySize(size);

        System.out.println("Name    = " + file.getName());
        System.out.println("Size    = " + size);
        System.out.println("Display = " + display);
    }
}

Here are the results of our program:

Name    = jdk-17_windows-x64_bin.exe
Size    = 159373640
Display = 151 MB

Maven Dependencies

<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.14.0</version>
</dependency>

Maven Central