一段java代码问题

[xx_dada]

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class MiniDrawPad extends JFrame {
private String names[]={
"New",
"Open",
"Save",
"Pencil",
"Line",
"Rect",
"fRect",
"Oval",
"fOval",
"Circle",
"fCircle",
"RoundRect",
"frRect",
"Rubber",
"Color",
"Stroke",
"Word" };


private Icon items[];
private JButton choices[];

private String tipText[]={
//这里是鼠标移动到相应按钮上面上停留时给出的提示说明条
//读者可以参照上面的按钮定义对照着理解
"Draw a new picture",
"Open a saved picture",
"Save current drawing",
"Draw at will",
"Draw a straight line",
"Draw a rectangle",
"Fill a ractangle",
"Draw an oval",
"Fill an oval",
"Draw a circle",
"Fill a circle",
"Draw a round rectangle",
"Fill a round rectangle",
"Erase at will",
"Choose current drawing color",
"Set current drawing stroke",
"Write down what u want"
};

public MiniDrawPad() //构造函数
{
super("Drawing Pad");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JToolBar bar=new JToolBar();
choices=new JButton[names.length];

for(int i=0;i<choices.length;i++)
{items[i]=new ImageIcon(names[i]+".gif");
choices[i]=new JButton("",items[i]);
choices[i].setToolTipText(tipText[i]);
bar.add(choices[i]);}



JTextArea edit=new JTextArea(8,40);
JScrollPane scroll=new JScrollPane(edit);
JPanel pane=new JPanel();
BorderLayout bord=new BorderLayout();
pane.setLayout(bord);
pane.add("North",bar);
pane.add("Center",scroll);

setContentPane(pane);

}
public static void main(String[] arguments){

JFrame newPad=new MiniDrawPad();
newPad.pack();
newPad.setVisible(true);
}
}

前辈我想知道这段代码哪里有问题，为什么执行不出来。多谢各位前辈了

[wenqin2006]

我觉得pane.add("BorderLayout.NORTH",bar);
pane.add("BorderLayout.CENTER",scroll);还有就是我觉得设置内容面板JFRAME要用getContentPane()方法样。也就是this.getContentPane().setContentPane(pane)我也是不很清楚。只是书上是这样写的，

[lwxaty]

把private Icon items[]改为private Icon items[]=new Icon[names.length];就出来啦