Question

java按钮图片设置

toolbar_main = new javax.swing.JToolBar();
bt_back = new javax.swing.JButton(new ImageIcon(this.getClass().getClassLoader().getResource("/back.jpg")));
bt_forward = new javax.swing.JButton(new ImageIcon(this.getClass().getClassLoader().getResource("/forward.jpg")));
bt_stop = new javax.swing.JButton(new ImageIcon(this.getClass().getClassLoader().getResource("/stop.jpg")));
bt_refresh = new javax.swing.JButton(new ImageIcon(this.getClass().getClassLoader().getResource("/refresh.jpg")));
bt_home = new javax.swing.JButton(new ImageIcon(this.getClass().getClassLoader().getResource("/home.jpg")));

显示这段代码出错·····
错误是

Exception in thread "AWT-EventQueue-0" java.lang.NullPointerException
at javax.swing.ImageIcon.<init>(Unknown Source)
at JWebBrowser.initComponents(JWebBrowser.java:51)
at JWebBrowser.<init>(JWebBrowser.java:35)
at JWebBrowser$5.run(JWebBrowser.java:367)
at java.awt.event.InvocationEvent.dispatch(Unknown Source)
at java.awt.EventQueue.dispatchEvent(Unknown Source)
at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.pumpEvents(Unknown Source)
at java.awt.EventDispatchThread.run(Unknown Source)

Answer 1

找不到图片文件，和.class文件包的ROOT中，没找到对应的图片文件

略作简化

bt_back = new javax.swing.JButton(new ImageIcon(this.getClass().getResource("/back.jpg")));
bt_forward = new javax.swing.JButton(new ImageIcon(this.getClass().getResource("/forward.jpg")));
bt_stop = new javax.swing.JButton(new ImageIcon(this.getClass().getResource("/stop.jpg")));
bt_refresh = new javax.swing.JButton(new ImageIcon(this.getClass().getResource("/refresh.jpg")));
bt_home = new javax.swing.JButton(new ImageIcon(this.getClass().getResource("/home.jpg")));

追问

怎么解决呢·？！怎么会找不到图片··图片就在根目录下··

Answer 2

图片路径是否写对

bt_home = new javax.swing.JButton(new ImageIcon("image\\00.jpg"));
bt_home = new javax.swing.JButton(Toolkit.getDefaultToolkit().getImage("image\\123.jpg"));

追问

路径是对的···图片就放在根目录下···

Answer 3

swing不能这样设置图片，需要重写jbutton里的drawComponent方法