java 错误

java 错误

package com.whatisjava;

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.*;

class Login extends JPanel {
static final int WIDTH = 300;

static final int HEIGHT = 150;

JFrame loginframe;

public void add(Component c, GridBagConstraints constraints, int x, int y,
int w, int h) {
constraints.gridx = x;
constraints.gridy = y;
constraints.gridwidth = w;
constraints.gridheight = h;
add(c, constraints);
}

Login(){
final JFrame loginframe=new JFrame("信息管理系统");
loginframe.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
GridBagLayout lay=new GridBagLayout();
setLayout(lay);
loginframe.add(this,BorderLayout.WEST);
loginframe.setSize(WIDTH,HEIGHT);
Toolkit kit=Toolkit.getDefaultToolkit();
Dimension screenSize=kit.getScreenSize();
int width=screenSize.width;
int height=screenSize.height;
int x=(width-WIDTH)/2;
int Y=(height-HEIGHT)/2;
loginframe.setLocation(x,Y);
JButton ok=new JButton("登录");
JButton cancel=new JButton("放弃");
JLabel title=new JLabel("信息系统登录窗口");
JLabel name=new JLabel("用户名");
JLabel password=new JLabel("密码");
final JTextField nameinput=new JTextField(15);
final JTextField passwordinput=new JTextField(15);
GridBagConstraints constraints=new GridBagConstraints();
constraints.fill=GridBagConstraints.NONE;
constraints.anchor=GridBagConstraints.EAST;
constraints.weightx=3;
constraints.weighty=4;
add(title,constraints,0,0,4,1);
add(name,constraints,0,1,1,1);
add(password,constraints,0,2,1,1);
add(nameinput,constraints,2,1,1,1);
add(passwordinput,constraints,2,2,1,1);
add(ok,constraints,0,3,1,1);
add(cancel,constraints,2,3,1,1);
loginframe.setResizable(false);
loginframe.setVisible(true);
ok.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent Event){
String nametext=nameinput.getText();
String passwordtext=passwordinput.getText();
String str=new String(passwordtext);
boolean x=(nametext.equals("starsong"));
boolean y=(str.equals("750720"));
boolean z=(x&&y);
if(z==true){
loginframe.dispose();
// mainframe main=new mainframe();
System.out.println("密码和用户名都对，可以进入学生信息系统了");
}
else if(z==false)
{
nameinput.setText("");
passwordinput.setText("");
}
}
});
cancel.addActionListener(new ActionListener(){
public void actionPerformed(ActionEvent Event){
loginframe.dispose();
}
});
}

public static void main(String[] arg) {
new Login();
}
}

给你改了一下..你自己 看看吧..

报错信息都没贴出来，怎么看？

问题很多
首先你的JLabel拼写错误不是JLable
你定义的变量Y(大写) ,下面程序用的小写
loginFrame应为final
建议你用IDE工具写代码,可以减少很多粗心的错误