GUI程序不是從BlueJ開始的

我試圖製作我的第一個GUI程序，我在Java上是一個大規模的noob，只是跟着一個教程讓我啓動並運行。我一行一行地複製下面的代碼，試圖理解發生了什麼，並且總體上我是。但是該程序無法在BlueJ中運行。虛擬機永遠不會踢GUI程序不是從BlueJ開始的

import javax.swing.JFrame; 
import javax.swing.JPanel; 
import javax.swing.JComboBox; 
import javax.swing.JButton; 
import javax.swing.JLabel; 
import javax.swing.JList; 
import java.awt.BorderLayout; 
import java.awt.event.ActionListener; 
import java.awt.event.ActionEvent; 



public class GUI{ 
    public void GUI(){ 
     JFrame guiFrame1= new JFrame(); 
     guiFrame1.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     guiFrame1.setTitle("First GUI"); 
     guiFrame1.setSize(300,250); 
     guiFrame1.setLocationRelativeTo(null); 

     String[] fruitOptions = {"Apple", "Apricot", "Banana" 
       ,"Cherry", "Date", "Kiwi", "Orange", "Pear", "Strawberry"}; 

     //Options for the JList 
     String[] vegOptions = {"Asparagus", "Beans", "Broccoli", "Cabbage" 
       , "Carrot", "Celery", "Cucumber", "Leek", "Mushroom" 
       , "Pepper", "Radish", "Shallot", "Spinach", "Swede" 
       , "Turnip"}; 


     //fruits 
     final JPanel comboPanel= new JPanel(); 
     JLabel comboLbl= new JLabel("Fruits"); 
     JComboBox fruits = new JComboBox(fruitOptions); 
     comboPanel.add(comboLbl); 
     comboPanel.add(fruits); 

     //veg 
     final JPanel listPanel= new JPanel(); 
     listPanel.setVisible(false); 
     JLabel listLbl1= new JLabel("Vegetables:"); 
     JList vegs= new JList (vegOptions); 
     vegs.setLayoutOrientation(JList.HORIZONTAL_WRAP); 

     listPanel.add(listLbl1); 
     listPanel.add(vegs); 

     //button 
     JButton vegFruitBut = new JButton("Fruit or Veg"); 

     vegFruitBut.addActionListener(new ActionListener() 
     { 
      @Override 
      public void actionPerformed(ActionEvent event) 
      { 
       listPanel.setVisible(!listPanel.isVisible()); 
       comboPanel.setVisible(!comboPanel.isVisible()); 
      } 

     }); 

     guiFrame1.add(comboPanel, BorderLayout.NORTH); 
     guiFrame1.add(listPanel, BorderLayout.CENTER); 
     guiFrame1.add(vegFruitBut,BorderLayout.SOUTH); 
     guiFrame1.setVisible(true); 


     } 

    public static void main(String args[]){ 
     GUI s= new GUI(); 

    } 
}

來源

2014-02-20 bsaid97