Archives: File IO

Java – Convert PNG to JPEG Image File

November 5, 2010 | By Prasanna Sherekar | Post comment

import java.awt.Color;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;

public class ConvertImageFile {

    public static void main(String[] args) {

        BufferedImage bufferedImage;

        try {

            //read image file
            bufferedImage = ImageIO.read(new File("c:\\javanullpointer.png"));

            // create a blank, RGB, same width and height, and a white background
            BufferedImage newBufferedImage = new BufferedImage(bufferedImage.getWidth(),
                bufferedImage.getHeight(), BufferedImage.TYPE_INT_RGB);
            newBufferedImage.createGraphics().drawImage(bufferedImage, 0, 0, Color.WHITE, null);

            // write to jpeg file
            ImageIO.write(newBufferedImage, "jpg", new File("c:\\javanullpointer.jpg"));

            System.out.println("Done");

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

}

import java.awt.Color;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.IOException;

import javax.imageio.ImageIO;

public class ConvertImageFile {

public static void main(String[] args) {

BufferedImage bufferedImage;

try {

//read image file

bufferedImage = ImageIO.read(new File("c:\\javanullpointer.png"));

// create a blank, RGB, same width and height, and a white background

BufferedImage newBufferedImage = new BufferedImage(bufferedImage.getWidth(),

bufferedImage.getHeight(), BufferedImage.TYPE_INT_RGB);

newBufferedImage.createGraphics().drawImage(bufferedImage, 0, 0, Color.WHITE, null);

// write to jpeg file

ImageIO.write(newBufferedImage, "jpg", new File("c:\\javanullpointer.jpg"));

System.out.println("Done");

} catch (IOException e) {

e.printStackTrace();

}

Java – Change File Date / Time using Commons FileUtils

September 15, 2010 | By Prasanna Sherekar | Post comment

import java.io.IOException;
import org.apache.commons.io.FileUtils;

import java.io.File;

public class Main {

    public static void main(String[] args) {
        try {
            File file = new File("pic.jpg");
            long lastModified1 = file.lastModified();
            FileUtils.touch(file);
            long lastModified2 = file.lastModified();
            System.out.println("File date / time was updated: " + (lastModified2 < lastModified1));
        } catch (IOException ex) {
            ex.printStackTrace();
        }
    }

}

import java.io.IOException;

import org.apache.commons.io.FileUtils;

import java.io.File;

public class Main {

public static void main(String[] args) {

try {

File file = new File("pic.jpg");

long lastModified1 = file.lastModified();

FileUtils.touch(file);

long lastModified2 = file.lastModified();

System.out.println("File date / time was updated: " + (lastModified2 < lastModified1));

} catch (IOException ex) {

ex.printStackTrace();

}

Output:

File date / time was updated: true

Java – Calculate Directory Size using Commons FileUtils

August 10, 2010 | By Prasanna Sherekar | Post comment

import java.io.File;
import org.apache.commons.io.FileUtils;

public class DirectorySizeSample {

    public static void main(String[] args) {

        // Using FileUtils.sizeOfDirectory() we can calculate
        // the size of a directory including it sub directory
        long size = FileUtils.sizeOfDirectory(new File("C:/Windows"));

        System.out.println("Size: " + size + " bytes");

    }
}

import java.io.File;

import org.apache.commons.io.FileUtils;

public class DirectorySizeSample {

public static void main(String[] args) {

// Using FileUtils.sizeOfDirectory() we can calculate

// the size of a directory including it sub directory

long size = FileUtils.sizeOfDirectory(new File("C:/Windows"));

System.out.println("Size: " + size + " bytes");

}