login.java

一个简单的选课系统的源代码,本人的数据库课程的作品.数据库用的是db2

package Student;



import javax.swing.*;

import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import java.util.Vector;

public class Login {

	public static void main(String[] args) {
		try {
			Frame1 login = new Frame1();
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}

class Frame1 extends JFrame
{
	static {
		try {
			Class.forName("COM.ibm.db2.jdbc.app.DB2Driver");
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	JButton jb1=new JButton();
	JButton jb2=new JButton();
	JButton jb3=new JButton();
	JTextField tx1=new JTextField(12);
	JPasswordField pw=new JPasswordField(12);
	
	JLabel jl=new JLabel();
	JLabel jl1=new JLabel();
	JLabel jl2=new JLabel();
	Container cp;
	Container thiswindow=this;
	public Frame1()
	{
		try{
			jbinit();
		}catch(Exception e){e.printStackTrace();}
	}
	private void jbinit()
	{
		cp=this.getContentPane();
		cp.setLayout(new BorderLayout());
		jb3.setText("退出");
		jb3.setFont(new Font("SansSerif", Font.PLAIN, 12));
		jb3.setForeground(Color.BLUE);
		jb3.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent e)
			{
				System.exit(0);
			}
		});
		jb1.setForeground(Color.BLUE);
		jb1.setText("清除");
		jb1.setFont(new Font("SansSerif", Font.PLAIN, 12));
		jb1.setForeground(Color.BLUE);
		jb2.setText("登入");
		jb2.setFont(new Font("SansSerif", Font.PLAIN, 12));
		jb2.setForeground(Color.BLUE);
		jb2.addActionListener(new ActionListener()
				{
			public void actionPerformed (ActionEvent e)
			{
				String password=pw.getText();
				String userid=tx1.getText();
				ResultSet rs;
				String key=null;

				try{
					
					MyJDBC getkey=new MyJDBC();
					rs=getkey.exceteQuery("SELECT sid,key FROM wengxinzhi.student where sid='"+userid+"'");

				while (rs.next()) {
					key=rs.getString(2);

				}
				if(key.equals(password))
				{
					StudentUI x=new StudentUI(userid,password);
					thiswindow.setVisible(false);
				}
				else 
				{
					JOptionPane.showMessageDialog(null,"You ID Or Password is wrong");
				}

				rs.close();
				}catch(Exception f){f.printStackTrace();
				JOptionPane.showMessageDialog(null,"不能连接数据库");}
			}
		}
		);
		
		JPanel jp1=new JPanel();
		jp1.add(jb1);
		jp1.add(jb2);
		jp1.add(jb3);
		jb1.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e)
			{
				pw.setText("");
				tx1.setText("");
			}
		});
		jl.setText("欢迎使用选课系统");
		jl.setFont(new Font("SansSerif", Font.BOLD, 24));
		jl.setForeground(Color.RED);
		jl1.setText("用户ID");
		jl1.setForeground(Color.GREEN);
		jl2.setText("密码  ");
		jl2.setForeground(Color.GREEN);
		JPanel jpt1=new JPanel();
		JPanel jpt2=new JPanel();
		JPanel jp2=new JPanel();
		jpt1.add(jl1);
		jpt1.add(tx1);
		jpt2.add(jl2);
		jpt2.add(pw);
		jp2.add(jpt1);
		jp2.add(jpt2);
		cp.add(jl,BorderLayout.NORTH);
		cp.add(jp1,BorderLayout.SOUTH);
		cp.add(jp2,BorderLayout.CENTER);
		this.setSize(300,250);

		this.setTitle("CRS-sutdent");
		this.setLocation(350,250);
		this.setVisible(true);
	}
}