为什么在NetBeans中出现“无法找到或加载主类……”错误？

Question

I am using netbeans on windows 7. I have created my main class in the creation of the program. I have been following a tutorial but for some reason I can never get it to populate the form. What am I missing here?

    package inventorygui;

import java.awt.Dimension;
import java.awt.Toolkit;
import javax.swing.*;


public class InventoryGUI extends JFrame {

    public static void main(String[] args) {
        new InventoryGUI();

    }

    public InventoryGUI() {
        this.setSize(400, 400);
        Toolkit tk = Toolkit.getDefaultToolkit();
        Dimension dim = tk.getScreenSize();
        int xPos = (dim.width / 2) - (this.getWidth() / 2);
        int yPos = (dim.height / 2) - (this.getHeight() / 2);

        this.setLocation(xPos, yPos);
        this.setResizable(false);

        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setTitle("Inventory Program");

        JPanel thePanel = new JPanel();
        JLabel label1 = new JLabel("Inventory Program Below");
        thePanel.add(label1);
        this.add(thePanel);





        this.setVisible(true);

    }
}

Answer 1

I tried compile it , it works fine no errors .
Notes : Be sure name of project as the public class ,also the name of package should be the same of package that you have . Try loading netbeans with another Jave SE version . Try loading it with Java SE 6.20 even its old, but works fine for netbeans on win7.