Question

我已经看过有关此例外的其他问题，但似乎常见的问题是扫描仪过早关闭，这不是这里的情况。这是我的代码，在问题行上方有一条评论：

    public void windowOpened(WindowEvent arg0) {

    Scanner input = null;

    try {
        input = new Scanner(new File("/home/brian/workspace/Color Sampler/src/Data.txt"));
    } catch (FileNotFoundException e) {
        System.exit(1);
    }

    int i = 0;
    int nR, nG, nB;
    String nName;
    while(input.hasNextLine())
    {
        // These lines are throwing the exception
        nName = input.next();
        nR = input.nextInt();
        nG = input.nextInt();
        nB = input.nextInt();

        ColorSampler.colors[i] = new myColor(nName, nR, nG, nB); 

        i++;
    }

    ColorSampler.currentColor = ColorSampler.colors[0];
    System.out.println(ColorSampler.currentColor.red);

}

以下是我得到的例外情况：

Exception in thread "AWT-EventQueue-1" java.util.NoSuchElementException
at java.util.Scanner.throwFor(Scanner.java:855)
at java.util.Scanner.next(Scanner.java:1364)
at WindowDestroyer.windowOpened(WindowDestroyer.java:57)
at java.awt.Window.processWindowEvent(Window.java:1972)
at javax.swing.JFrame.processWindowEvent(JFrame.java:290)
at java.awt.Window.processEvent(Window.java:1933)
at java.awt.Component.dispatchEventImpl(Component.java:4649)
at java.awt.Container.dispatchEventImpl(Container.java:2103)
at java.awt.Window.dispatchEventImpl(Window.java:2588)
at java.awt.Component.dispatchEvent(Component.java:4475)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:675)
at java.awt.EventQueue.access$300(EventQueue.java:96)
at java.awt.EventQueue$2.run(EventQueue.java:634)
at java.awt.EventQueue$2.run(EventQueue.java:632)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:108)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:119)
at java.awt.EventQueue$3.run(EventQueue.java:648)
at java.awt.EventQueue$3.run(EventQueue.java:646)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.AccessControlContext$1.doIntersectionPrivilege(AccessControlContext.java:108)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:645)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:275)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:200)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:190)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:185)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:177)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:138)

我无法弄清楚这里会出现什么问题。有人可以帮忙吗？

Answer 1

默认情况下，在扫描程序中使用空格查找标记。当它无法在特定读取上找到令牌时，它将继续从源读取所有数据，直到它为止。

来自Scanner.next（）

的来源

while (true) {
    String token = getCompleteTokenInBuffer(null);
    if (token != null) {
        matchValid = true;
        skipped = false;
        return token;
    }
    if (needInput)
        readInput();
    else
        throwFor();
}

因此，请注意确保您使用空格来定义文件中的标记。

扫描器在调用next（）时抛出NoSuchElementException

1 个答案: