dl.java

小程序 自己写的 请多多指教 希望高手不吝赐教

import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;
import java.awt.geom.*;
 class denglu extends Frame
{  
   public Label name=new Label("用户名");
   public Label pass=new Label("密码");
   public TextField txtname=new TextField();
   public TextField txtpass=new TextField();
   public Button btok=new Button("登陆");
   public Button btexit=new Button("取消");
   public condb conu=new condb(); 
   private String sql=null;
   private ResultSet rs=null;
   private Image img;
   
   public denglu()
   {
	img=getToolkit().getImage(getClass().getResource("/ww.jpg")); 
	
	

   setTitle("欢迎使用物流信息系统");
   setLayout(null);

   setResizable(false);
   setSize(500,350);
  
   Dimension scr=Toolkit.getDefaultToolkit().getScreenSize();
   Dimension frm=this.getSize();
   setLocation((scr.width-frm.width)/2,(scr.height-frm.height)/2-18);
   txtpass.setEchoChar('*');

   txtname.setBounds(120,260,120,27);
   txtpass.setBounds(120,300,120,27);
   btok.setBounds(340,260,100,28);
   btexit.setBounds(340,300,100,28);

   add(name);
   add(txtname);
   add(pass);
   add(txtpass);
   add(btok);
   add(btexit);
   setVisible(true);

    

   btexit.addActionListener(new ActionListener(){
              public void actionPerformed(ActionEvent e){
                  dispose();
                   System.exit(0);
                  }    });
   btok.addActionListener(new ActionListener()
     {
       public void actionPerformed(ActionEvent e)
           {
             sql="select * from 数据库用户 where 用户名='"+txtname.getText()+"' and 密码='"+txtpass.getText()+"'";
        try { 
              rs=conu.getrs(conu.con,sql);
        	  if(rs.next())
   
                   { mainff mf=new mainff();
                     dispose();
                     mf.show();
                    
                     }
                 else { JOptionPane jop=new JOptionPane();
                       jop.showMessageDialog(null,"用户名或密码错误","信息提示!",-1);}
   
             }catch(Exception ee){}
           }
        } );
		
    addWindowListener( new WindowAdapter()
                        {public void windowClosing(WindowEvent e)
                            { dispose();
                              System.exit(0);
                             }
                         }  );
					
    }
	public void paint(Graphics g)
         {
          g.setClip(new Rectangle2D.Float(0,0,500,350));
          g.drawImage(img,0,0,this);

        }	

}
 
public class dl
{ public static void main(String args[])
  { denglu deng=new denglu();
   }

}