Java 防止jSpinner中出现负值

Java 防止jSpinner中出现负值,java,swing,netbeans,jspinner,changelistener,Java,Swing,Netbeans,Jspinner,Changelistener,我正在使用netbeans用java构建gui应用程序。它有一个jSpinner。我将其最小值设置为0。当我运行并单击向下箭头按钮时,我得到negativearraysizeexception。有什么解决办法吗 //此代码是在netbeans中自动生成的 protected void fireStateChanged() { Object[] listeners = listenerList.getListenerList(); for (int i = listeners.le

我正在使用netbeans用java构建gui应用程序。它有一个jSpinner。我将其最小值设置为0。当我运行并单击向下箭头按钮时,我得到negativearraysizeexception。有什么解决办法吗

//此代码是在netbeans中自动生成的

protected void fireStateChanged() {
    Object[] listeners = listenerList.getListenerList();
    for (int i = listeners.length - 2; i >= 0; i -= 2) {
        if (listeners[i] == ChangeListener.class) {
            if (changeEvent == null) {
                changeEvent = new ChangeEvent(this);
            }
            ((ChangeListener)listeners[i+1]).stateChanged(changeEvent);
        }
    }
}

尝试以下方法,而不是NetBeans自动生成的代码:

import javax.swing.JFrame;
import javax.swing.JSpinner;
import javax.swing.SpinnerModel;
import javax.swing.SpinnerNumberModel;
import javax.swing.SwingUtilities;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class Spinner {

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                JFrame frame = new JFrame("Spinner demo");
               //10 is init value, 0 is minimum, 20 maximum and 1 is step
                SpinnerModel model = new SpinnerNumberModel(10, 0, 20, 1);
                JSpinner spinner = new JSpinner(model);
                spinner.addChangeListener(new ChangeListener() {
                    public void stateChanged(ChangeEvent e) {
                        JSpinner s = (JSpinner)e.getSource();
                        int val = (int)s.getValue();
                        System.out.println(val);
                    }
                });

                frame.add(spinner);
                frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                frame.pack();
                frame.setVisible(true);
            }
        });
    }
}

它返回正确的值。没有否定的。祝你好运

有点晚了,但在Netbeans中有一个自动生成代码的解决方案:
jSpinner->properties->second row“model”单击[…],您有不同的选项:)

显示您的代码。准确地说…监听器内部的代码。以及异常的完整堆栈跟踪。首先尝试,然后接受答案…无需匆忙!顺便说一句,不客气。