How to display an image in a Frame object

[Cyrus Serrano]

hello all,

how can i paste or display an image inside a Frame object? codes that i usually see are image displayed along with Applets? is it possible on Frames..

thank you.

Cyrus

[Craig Wood]

Displaying an image is fairly easy. Pasting an image into an app is a little more complex. This example requires j2se 1.4+

import java.awt.*;
import java.awt.event.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.net.*;
import javax.imageio.ImageIO;
 
public class FrameImage
{
    public FrameImage()
    {
        ScrollPane scrollPane = new ScrollPane();
        scrollPane.add(new FrameImagePanel());
        Frame f = new Frame();
        f.addWindowListener(new WindowAdapter()
        {
            public void windowClosing(WindowEvent e)
            {
                System.exit(0);
            }
        });
        f.add(scrollPane);
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
    }
 
    public static void main(String[] args)
    {
        new FrameImage();
    }
}
 
class FrameImagePanel extends Panel
{
    BufferedImage image;
 
    public FrameImagePanel()
    {
        loadImage();
    }
 
    public void paint(Graphics g)
    {
        super.paint(g);
        int w = getWidth();
        int h = getHeight();
        int imageWidth = image.getWidth();
        int imageHeight = image.getHeight();
        int x = (w - imageWidth)/2;
        int y = (h - imageHeight)/2;
        g.drawImage(image, x, y, this);
    }
 
    public Dimension getPreferredSize()
    {
        return new Dimension(image.getWidth(), image.getHeight());
    }
 
    private void loadImage()
    {
        String fileName = "images/bclynx.jpg";
        try
        {
            URL url = getClass().getResource(fileName);
            image = ImageIO.read(url);
        }
        catch(MalformedURLException mue)
        {
            System.err.println("url: " + mue.getMessage());
        }
        catch(IOException ioe)
        {
            System.err.println("read: " + ioe.getMessage());
        }
    }
}

[Cyrus Serrano]

sir

i will try your code..

thanks for the help

[Cyrus Serrano]

@sir craig wood,

i tried to use your code, i modified the line which details the filename of the image:

String fileName = "images/a1.jpg";

sir, should the java program and the image file be located on the same folder, Or should i create a new subfolder then copy the image on that folder.

My Directory Structure

drive c:
|----- java folder
++++++++++++|----- FrameImage.java
++++++++++++|----- images folder
++++++++++++++++++++++++|----- a1.jpg



it has returned this error:

Exception in thread "main" java.lang.IllegalArgumentException : input ==null!

at javac.imageio.ImageIO.read(Unknown Source)
at FrameImagePanel.loadImage(FrameImage.java:66)
at FrameImagePanel.<init>(FrameImage.java:40)
at FrameImage.<init>(FrameImage.java:13)
at FrameImage.main(FrameImage.java:30)



thanks sir..
[ March 02, 2005: Message edited by: Cyrus Serrano ]

[Craig Wood]

should the java program and the image file be located on the same folder, Or should i create a new subfolder then copy the image on that folder
Either way is okay. The hardest part is to figure out how to get the image to display for the first time. The error indicates that the class loader could not find the image. You can add a System.out.println statement to check the url that the class loader is using to find the image, like this:

        try
        {
            URL url = getClass().getResource(fileName);
            System.out.println("url = " + url);
            image = ImageIO.read(url);
        }

With the getResource method the image file needs to be on the classpath. Inside the same folder as your class files should be okay. You could also try constructing a full URL with a protocol of file:

            URL url = new URL("file:/path/to/file/fileName");

although this can be tricky to get right. You just have to play around with it till you figure it out.

You can make up a small test application to experiment with this

import java.net.*;
 
class Test
{
    public static void main(String[] args)
    {
        URL url = Test.class.getResource("images/cougar.jpg");
        System.out.println("url = " + url);
    }
}

Here's what I got when I ran it

C:\jexp>java Test
url = file:/C:/jexp/images/cougar.jpg

As you can see the images folder is in the current directory (same as what you show in your last post). You can use the string printed to the console in the new URL constructor

            URL url = new URL("file:/C:/jexp/images/cougar.jpg");

[Cyrus Serrano]

sir craig

thanks a lot.. i've got it finally