编译通过,小程序查看器却未初始化,DOS界面抛出NullPointerException,是什么原因啊?

来源:百度知道 编辑:UC知道 时间:2024/06/27 05:41:51
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class count2 extends JFrame
{
JPanel big,s1,s2,s3,s4,s5,s6,s7,s8;
JButton b1,b2,b3;
JTextField j1,j2;
Label l1,l2,l3,l4,l5,l6;
List c1,c2;
public count2()
{
big=new JPanel();
getContentPane().add(big);
big.setLayout(new GridLayout(8,1,0,0));
setTitle("首次运行设置");
s1=new JPanel();
s2=new JPanel();
s3=new JPanel();
s4=new JPanel();
s5=new JPanel();
s6=new JPanel();
s7=new JPanel();
s8=new JPanel();
big.add(s1);
big.add(s2);
big.add(s3);
big.add(s4);
big.add(s5);
big.add(s6);
big.add(s7);
big.add(s8);
s1.setLayout(new FlowLayout(FlowLayout.RIGHT,10,10));
l1=new Label("欢迎使用正欢学生理财软件");
s1.add(j1);

s2.setLayout(new GridLayout(1,2));
l2=new Label("我的个人资料");
b3=new JButton("隐私保护条款");
s2.add(

你的程序太多错误了,比如:
l1=new Label("欢迎使用正欢学生理财软件");
s1.add(j1);
此时j1还没有new,怎么能添加?

还有
l4=new Label("真实姓名(N)");
j2=new JTextField();
s5.add(l5);
此时l5还没有new,怎么能添加?

另外,报错:是类似下面的代码,可以看到下面已经指出错误位置了,92行:
Exception in thread "main" java.lang.NullPointerException
at java.awt.Container.addImpl(Unknown Source)
at java.awt.Container.add(Unknown Source)
at count2.<init>(count2.java:92)
at count2.main(count2.java:109)