52
votes

I want to have a place to store my image files to use in my Java project (a really simple class that just loads an image onto a panel). I have looked everywhere and cannot find how to do this. How do I do this?

I have tried adding a new folder to the project, adding a new class folder to the project, and adding a new source folder to the project. No matter what I do, I always get a IOException. The folders always say they are on the build path, so I'm not sure what to do.

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class PracticeFrame extends JFrame{

private static BufferedImage image;
Thread thread;

public PracticeFrame() {
    super();
    setPreferredSize(new Dimension(640,480));
    setResizable(false);
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    pack();
    setVisible(true);
}

public static void main (String[] args) {
    PracticeFrame pframe = new PracticeFrame();
    try {
        image = ImageIO.read(new File("/islands.png"));
    } catch (IOException e) {
        e.printStackTrace();
    }

    JPanel panel = new JPanel() {
        @Override
        protected void  paintComponent(Graphics g) {
            super.paintComponent(g);
            g.drawImage(image,0,0,null);
        }
    };

    panel.setBackground(Color.BLUE);
    panel.repaint();
    pframe.add(panel);


}


}

EDIT: Something that worked for me, and I have no idea why, was adding the main/res/ folder as a class folder and then removing it. I ran it while the /main/res/ was part of the build path as a class folder and it still didn't work. When i added it, i got a popup that told me something about excluded filters. But when i removed the folder from the libraries in the build path, and changed my file path to:

image = ImageIO.read(new File("src/main/res/islands.png"));

I at least stopped getting the IOException thrown. I must not be adding the image to the panel correctly, because it's not showing up, but at least it found the file (I think).

8
Show the code that produces the exception. You probably specify incorrect path.PM 77-1
@PM77-1 that is the code I've used for each different way of adding the res folderredeagle47
Please post your project directory structure and let us know your destination for .class files.PM 77-1
I have everything set up like this right now: workspace/JFramePractice/src/main/res/islands.png my .class files are here: workspace/JFramePractice/bin/*.classredeagle47
Right Click on your project > New > Source Foldervinsinraw

8 Answers

76
votes

When at the "Add resource folder", Build Path -> Configure Build Path -> Source (Tab) -> Add Folder -> Create new Folder enter image description here

add "my-resource.txt" file inside the new folder. Then in your code:

    InputStream res =
    Main.class.getResourceAsStream("/my-resource.txt");

    BufferedReader reader =
        new BufferedReader(new InputStreamReader(res));
    String line = null;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }
    reader.close();
13
votes

To answer your question posted in the title of this topic...

Step 1--> Right Click on Java Project, Select the option "Properties" Step 1--> Right Click on Java Project, Select the option "Properties"

Step 2--> Select "Java Build Path" from the left side menu, make sure you are on "Source" tab, click "Add Folder" Select "Java Build Path" from the left side menu, make sure you are on "Source" tab, click "Add Folder"

Step 3--> Click the option "Create New Folder..." available at the bottom of the window Click the option "Create New Folder..." available at the bottom of the window

Step 4--> Enter the name of the new folder as "resources" and then click "Finish" Enter the name of the new folder as "resources" and then click "Finish"

Step 5--> Now you'll be able to see the newly created folder "resources" under your java project, Click "Ok", again Click "Ok"
Now you'll be able to see the newly created folder "resources" under your java project, Click "Ok", again Click "Ok"

Final Step --> Now you should be able to see the new folder "resources" under your java project
Now you should be able to see the new folder "resources" under your java project

3
votes

After adding a resource folder try this :

ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
InputStream input = classLoader.getResourceAsStream("test.png");

try {
    image = ImageIO.read(input);
} catch (IOException e) {
    e.printStackTrace();
}
1
votes

Build Path -> Configure Build Path -> Libraries (Tab) -> Add Class Folder, then select your folder or create one.

1
votes

Right click on project >> Click on properties >> Java Build Path >> Source >> Add Folder

1
votes

If you have multiple sub-projects then you need to add the resources folder to each project's run configuration class path like so:

class path

Ensure the new path is top of the entries and then the runtime will check that path first for any resources (before checking sub-paths)

0
votes

Try To Give Full path for reading image.

Example image = ImageIO.read(new File("D:/work1/Jan14Stackoverflow/src/Strawberry.jpg"));

your code is not producing any exception after giving the full path. If you want to just read an image file in java code. Refer the following - http://docs.oracle.com/javase/tutorial/2d/images/examples/LoadImageApp.java

If the object of your class is created at end your code works fine for me and displays the image

// PracticeFrame pframe = new PracticeFrame();//comment this

new PracticeFrame().add(panel);
0
votes

If aim is to create a resources folder parallel to src/main/java, then do the following:

Right Click on your project > New > Source Folder
Provide Folder Name as src/main/resources
Finish