new ImageIcon("src/Action-exit-icon.png");在
String一个构造函数
ImageIcon假定表示一个字符串
File路径。
该映像显然是应用程序资源，并且在部署时（在Jar中）将成为嵌入式资源。因此，必须
URL从应用程序的运行时类路径访问它，如下所示：
new ImageIcon(getClass().getResource("/src/Action-exit-icon.png"));全面检查代码，我得到以下信息：
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() { 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); }}
