java - malformedURLException 图像上没有协议(protocol)

Question

我使用了以下代码:

g.drawImage(Toolkit.getDefaultToolkit().createImage(new  
URL(".\\mouseicon1.bmp")), MouseX,MouseY,null);

和图像文件(mouseicon1.bmp)位于同一个包中，但它抛出此异常:

java.net.MalformedURLException: no protocol: .\mouseicon1.bmp
    at java.net.URL.<init>(Unknown Source)
    at java.net.URL.<init>(Unknown Source)
    at java.net.URL.<init>(Unknown Source)
    at (insertnameofpackagehere).launch$Board.paint(launch.java:48)
    at javax.swing.JComponent.paintToOffscreen(Unknown Source)
    at javax.swing.BufferStrategyPaintManager.paint(Unknown Source)
    at javax.swing.RepaintManager.paint(Unknown Source)
    at javax.swing.JComponent._paintImmediately(Unknown Source)
    at javax.swing.JComponent.paintImmediately(Unknown Source)
    at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.paintDirtyRegions(Unknown Source)
    at javax.swing.RepaintManager.seqPaintDirtyRegions(Unknown Source)
    at javax.swing.SystemEventQueueUtilities$ComponentWorkRequest.run(Unknown Source)
    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

正如错误所示，URL 需要一个协议(protocol)。对于本地文件，您可以在使用 URL 时使用 file://作为协议(protocol)。或者您可以将文件转换为 URL:

new File(path).toURI().toURL();