| 发表于：2007-05-29 23:11:55 楼主 |
package yan1;
import javax.swing.*;
import javax.swing.table.*;
import java.awt.*;
import java.awt.event.*;
//vist bbs java
public class customer extends jframe {
// variables of labels
jlabel heading;
jlabel labelcustno;
jlabel labelcustname;
jlabel labelcustsex;
jlabel labelcustage;
// variables for data entry controls
jtextfield textcustno;
jtextfield textcustname;
jcombobox combocustsex;
jtextfield textcustage;
customer（) {
super（ "customer ");
container con;
con = this.getcontentpane（);
con.setlayout（new flowlayout（));
// initializing textfield
textcustno = new jtextfield（20);
textcustname = new jtextfield（25);
textcustage = new jtextfield（);
string sex[] = { "male ", "female " };
combocustsex = new jcombobox（sex);
// adding controls for customer number
con.add（labelcustno);
con.add（textcustno);
// adding controls for customer name
con.add（labelcustname);
con.add（textcustname);
// adding controls for customer sex
con.add（labelcustsex);
con.add（combocustsex);
// adding controls for customer age
con.add（labelcustage);
con.add（textcustage);
// close the program when close button is clicked
setdefaultcloseoperation（exit_on_close);
setsize（350, 250);
show（);
}
public static void main（string[] args) {
customer cust = new customer（);
}
}
错误提示为：
exception in thread "main " java.lang.nullpointerexception
at java.awt.container.addimpl（unknown source)
at java.awt.container.add（unknown source)
at yan1.customer. <init> （customer.java:42)
at yan1.customer.main（customer.java:61)
请哪一位高手帮忙看啊～我调试了好久，小弟现在在学java开发环境是eclipse+myeclipse,jdk1.4
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