加载图标资源错误 [英] Loading Icon resource error

问题描述

在Eclipse中，当我运行代码时，这可行：

In Eclipse, when I run the code, this works:

import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;


   public class Main {

    public static void main(String[] args) {

        JFrame frame = new JFrame("test viewing images");

        frame.setSize(600,300);     
        frame.setLocationRelativeTo(null); // centered on monitor   
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);


        /**
         * Menu Bar stuff
         */

        JMenuBar menuBar;
        JMenu menu;
        JMenuItem menuItem;

        // MENU BAR 
        menuBar = new JMenuBar();
        frame.setJMenuBar(menuBar);
        menuBar.setVisible(true);

        // MENU 1
        menu = new JMenu("File");
        menuBar.add(menu);

            // MENU 1 ITEM
            ImageIcon icon = new ImageIcon("src/Action-exit-icon.png");     
            menuItem = new JMenuItem("Exit Program", icon);
            menu.add(menuItem);


        frame.setVisible(true);

    }

   }

这是我的包资源管理器中的文件结构：

And here's the File Structure from my Package Explorer:

ShowImage (project)
 > src / Main.java
 > src / Action-exit-icon.png

此外，此工作空间位于Z：\ eclipse_projects

Also, this workspace is located in Z:\eclipse_projects

我可以看到 ImageIcon icon = new ImageIcon（src / Action-exit-icon.png）; 工作正常， menuBar是它的工作。

I can see the ImageIcon icon = new ImageIcon("src/Action-exit-icon.png"); is working nicely, and the menuBar does it's job.

现在让我们导出这个项目，我会把JAR发给我的一个朋友。

Now let's Export this project, and I'll email the JAR to a friend of mine.

1. 右键单击项目>选择导出


2. 选择Java> Runnable JAR文件


3. 我选择启动配置中的主文件


4. 导出目标：我的桌面


5. 库处理：将所需库提取到生成的JAR中


6. 转到我的桌面，双击ShowImage.jar

1. Right-click project > Select Export
2. Select Java > Runnable JAR File
3. I choose the Main File in Launch configuration
4. Export destination: my desktop
5. Library handling: Extract required libraries into generated JAR
6. go to my desktop, double-click the ShowImage.jar

JFrame显示，但 Action-exit -icon.png 根本没有出现。

The JFrame shows up, but the Action-exit-icon.png isn't appearing at all.

当我打开ShowImage.jar，查看它的内容时，我看到Main.class， Action-exit-icon.png，META-INF。

When I open the ShowImage.jar, to view it's contents, I see the Main.class, Action-exit-icon.png, META-INF.

好的，我对如何引用图像或任何资源感到非常困惑。
我做错了什么？

Ok, I'm seriously confused about how to reference an image, or any resource now. What am I doing wrong?

推荐答案

new ImageIcon("src/Action-exit-icon.png"); 

<$ c的字符串构造函数$ c> ImageIcon 假定字符串代表文件路径。

The String constructor for an ImageIcon presumes the string to represent a File path.

这个图像显然是一个应用程序资源，在部署时（在Jar中）将成为一个嵌入式资源。因此，必须从应用程序的运行时类路径中通过 URL 访问它，如下所示：

This image is obviously an application resource, and will become an embedded resource by the time of deployment (in a Jar). Therefore it must be accessed by URL from the run-time class-path of the app., like so:

new ImageIcon(getClass().getResource("/src/Action-exit-icon.png")); 

---

检修代码，我明白了：

---

Overhauling the code, I get this:

import java.awt.Color;
import javax.swing.*;

public class JavaGui148 {

    public JComponent getGUI() {
        JPanel p = new JPanel();

        p.setBackground(Color.GREEN);

        return p;
    }

    public JMenuBar getMenuBar() {
        /**
         * Menu Bar stuff
         */
        JMenuBar menuBar;
        JMenu menu;
        JMenuItem menuItem;

        // MENU BAR 
        menuBar = new JMenuBar();
        menuBar.setVisible(true);

        // MENU 1
        menu = new JMenu("File");
        menuBar.add(menu);

        // MENU 1 ITEM
        ImageIcon icon = new ImageIcon(getClass().getResource(
                "/src/Action-exit-icon.png"));
        menuItem = new JMenuItem("Exit Program", icon);
        menu.add(menuItem);

        return menuBar;
    }

    public static void main(String[] args) {
        Runnable r = new Runnable() {

            @Override
            public void run() {
                JavaGui148 gui = new JavaGui148();

                JFrame f = new JFrame("Demo");
                f.setJMenuBar(gui.getMenuBar());
                f.add(gui.getGUI());
                // Ensures JVM closes after frame(s) closed and
                // all non-daemon threads are finished
                f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                // See http://stackoverflow.com/a/7143398/418556 for demo.
                f.setLocationByPlatform(true);

                // ensures the frame is the minimum size it needs to be
                // in order display the components within it
                f.pack();
                // should be done last, to avoid flickering, moving,
                // resizing artifacts.
                f.setVisible(true);
            }
        };
        // Swing GUIs should be created and updated on the EDT
        // http://docs.oracle.com/javase/tutorial/uiswing/concurrency/initial.html
        SwingUtilities.invokeLater(r);
    }
}

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