How do I add a resources folder to my Java project

问题:

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).

回答1:

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

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();

回答2:

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

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"

Step 3--> 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"

Step 5--> 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

回答3:

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();
}

回答4:

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);

回答5:

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

回答6:

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

回答7:

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