Question

关于JAVA 的问题！高手请进！急！！！

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

public class Ticketing extends JFrame
{
//declare class varibles
//jp,jl,jb,jtf indicate the component typs
//JPanle,JLabel,JButton,JTextField respectively;
private JPanel jpTitle,jpSeat,jpInfo,jpRpack,jpSum,jpTop,jpBottom;
private JButton jb1,jb2,jb3,jb4,jb5,jb6,jb7,jb8,jb9,jb10,jb11,jb12,jb13,jb14;
private JButton jb15,jbCon,jbReset;
private JLabel jlTitle,jlReserve,jlSeat,jlPrice,jlRPack,jlQuantity,jlNumOfSeat;
private JLabel jlCost1,jlTicket,jlCost2,jlRF,jlPayment;
private JTextField jtf1;

public static void main(String[] args)
{
Ticketing t=new Ticketing();
t.setVisible(true);
}//end of main

/* constructor */
public Ticketing()
{
setSize(600,800);
setTitle("OTS");
getContentPane().setLayout(new BorderLayout(4,1));

/*****jpTop to contain jpTitle,jpREserve,jpSeat,jpInfo*****/
jpTop=new JPanel();
jpTop.setLayout(new BorderLayout());

/****Title****/
jpTitle=new JPanel();
jpTitle.setLayout(new GridLayout(2,1));
//Font bigFont=new Font("TimesRoman", Font.BOLD,24);
//jpTitle.setBackground(Color.yellow);
jlTitle=new JLabel("Roxy Theatres - Online Ticketing System");
//jlTitle.setFont(bigFont);
jlReserve=new JLabel("Reserve seats by clicking on them!");
jpTitle.add(jlTitle);
jpTitle.add(jlReserve);
jpTop.add(jpTitle,BorderLayout.NORTH);

/****Seat****/
jpSeat=new JPanel();
jpSeat.setLayout(new GridLayout(5,3,10,10));
jb1=new JButton();
jb2=new JButton();
jb3=new JButton();
jb4=new JButton();
jb5=new JButton();
jb6=new JButton();
jb7=new JButton();
jb8=new JButton();
jb9=new JButton();
jb10=new JButton();
jb11=new JButton();
jb12=new JButton();
jb13=new JButton();
jb14=new JButton();
jb15=new JButton();
jpSeat.add(jb1);
jpSeat.add(jb2);
jpSeat.add(jb3);
jpSeat.add(jb4);
jpSeat.add(jb5);
jpSeat.add(jb6);
jpSeat.add(jb7);
jpSeat.add(jb8);
jpSeat.add(jb9);
jpSeat.add(jb10);
jpSeat.add(jb11);
jpSeat.add(jb12);
jpSeat.add(jb13);
jpSeat.add(jb14);
jpSeat.add(jb15);
jpTop.add(jpSeat,BorderLayout.CENTER);

/****Information****/
jpInfo=new JPanel();
jlSeat=new JLabel("Seats Available:BLUE Reserved:RED");
jlPrice=new JLabel("Price per ticket: $8.50($8 promo price for 3 or more)");
jpInfo.add(jlSeat);
jlPrice.add(jlPrice);
jpTop.add(jpSeat,BorderLayout.SOUTH);

getContentPane().add(jpTop);
getContentPane().add(jpBottom);
}}

这个程序在Jcreator里编译成功，但运行时出现：
Exception in thread "main" java.lang.IllegalArgumentException: adding container'
s parent to itself
at java.awt.Container.addImpl(Container.java:1005)
at java.awt.Container.add(Container.java:351)
at Ticketing.<init>(Ticketing.java:86)
at Ticketing.main(Ticketing.java:19)

Answer 1

这里：

jlPrice.add(jlPrice);

怎么能自己添加自己呢？？？！！！！！
还有，你的JButtom在哪里定义的？？？

给你凑乎的改了一下:

自己看吧:

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

//import java.awt.event.*;

public class Ticketing extends JFrame {
// declare class varibles
// jp,jl,jb,jtf indicate the component typs
// JPanle,JLabel,JButton,JTextField respectively;
private JPanel jpTitle, jpSeat, jpInfo, jpRpack, jpSum, jpTop, jpBottom;

private JButton jb1, jb2, jb3, jb4, jb5, jb6, jb7, jb8, jb9, jb10, jb11,
jb12, jb13, jb14;

private JButton jb15, jbCon, jbReset;

private JLabel jlTitle, jlReserve, jlSeat, jlPrice, jlRPack, jlQuantity,
jlNumOfSeat;

private JLabel jlCost1, jlTicket, jlCost2, jlRF, jlPayment;

private JTextField jtf1;

public static void main(String[] args) {
Ticketing t = new Ticketing();
t.setVisible(true);
}// end of main

/* constructor */
public Ticketing() {
setSize(400,600);//600, 800);
setTitle("OTS");
getContentPane().setLayout(new BorderLayout(4, 1));

/** ***jpTop to contain jpTitle,jpREserve,jpSeat,jpInfo**** */
jpTop = new JPanel();
jpTop.setLayout(new BorderLayout());

/** **Title*** */
jpTitle = new JPanel();
jpTitle.setLayout(new GridLayout(2, 1));
// Font bigFont=new Font("TimesRoman", Font.BOLD,24);
// jpTitle.setBackground(Color.yellow);
jlTitle = new JLabel("Roxy Theatres - Online Ticketing System");
// jlTitle.setFont(bigFont);
jlReserve = new JLabel("Reserve seats by clicking on them!");
jpTitle.add(jlTitle);
jpTitle.add(jlReserve);
jpTop.add(jpTitle, BorderLayout.NORTH);

/** **Seat*** */
jpSeat = new JPanel();
jpSeat.setLayout(new GridLayout(5, 3, 10, 10));
jb1 = new JButton();
jb2 = new JButton();
jb3 = new JButton();
jb4 = new JButton();
jb5 = new JButton();
jb6 = new JButton();
jb7 = new JButton();
jb8 = new JButton();
jb9 = new JButton();
jb10 = new JButton();
jb11 = new JButton();
jb12 = new JButton();
jb13 = new JButton();
jb14 = new JButton();
jb15 = new JButton();
jpSeat.add(jb1);
jpSeat.add(jb2);
jpSeat.add(jb3);
jpSeat.add(jb4);
jpSeat.add(jb5);
jpSeat.add(jb6);
jpSeat.add(jb7);
jpSeat.add(jb8);
jpSeat.add(jb9);
jpSeat.add(jb10);
jpSeat.add(jb11);
jpSeat.add(jb12);
jpSeat.add(jb13);
jpSeat.add(jb14);
jpSeat.add(jb15);
jpTop.add(jpSeat, BorderLayout.CENTER);

/** **Information*** */
jpInfo = new JPanel();
jlSeat = new JLabel("Seats Available:BLUE Reserved:RED");
jlPrice = new JLabel(
"Price per ticket: $8.50($8 promo price for 3 or more)");
jpInfo.add(jlSeat);
jpBottom = new JPanel();
jpBottom.add(jlPrice);
jpTop.add(jpInfo, BorderLayout.SOUTH);

getContentPane().add(jpTop,BorderLayout.CENTER);
getContentPane().add(jpBottom,BorderLayout.SOUTH);
}
}

Answer 2

你这段代码做什么偶看不出来
但是偶知道你错在什么地方啊
要把红旗送给偶的哦
1 倒数第2行
getContentPane().add(jpBottom);
这是一个空指针异常拉,你没有创建jpBottom这个对象拉

2 jlPrice.add(jlPrice);
这个...,你怎么能用自己添加自己呢,晕
JPanel这个类有好多add()方法继承自Container类,自己慢慢看哈,但是就是不可以自己添自己 >_<!

Answer 3

看清楚了你的jlPrice是声明的什么实例啊，怎么可以有jlPrice.add(jlPrice); 呢？
还有你的jpBottom也没有创建，声明对象时后面都少了逗点符！

Answer 4

来个高手帮他啊 我是没希望了~