login.java

用java语言编写的银行管理系统

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

public class Login extends JFrame implements ActionListener
{	
	JPanel panel1,panel2;
	JLabel UserLabel,PasswordLabel;
	JTextField UserTextField;
	JPasswordField PasswordTextField;
	JButton YesBtn,CancelBtn,register;
	Container c;

	public Login()
	{
		super("客户登录");
		
		UserLabel=new JLabel("帐号",JLabel.CENTER);
		PasswordLabel=new JLabel("密码",JLabel.CENTER);
		
		UserTextField=new JTextField(10);
		PasswordTextField=new JPasswordField(10);
		YesBtn=new JButton("确定");
		CancelBtn=new JButton("取消");
		register=new JButton("开户");
		
		YesBtn.addActionListener(this);
		CancelBtn.addActionListener(this);
		register.addActionListener(this);
		
		panel1=new JPanel();
                panel1.setLayout(new GridLayout(3,3));
		panel2=new JPanel();
		
		c=getContentPane();
		c.setLayout(new BorderLayout());
                panel1.add(UserLabel);
                panel1.add(UserTextField);
                panel1.add(PasswordLabel);
                panel1.add(PasswordTextField);
                panel1.add(YesBtn);
                panel1.add(CancelBtn);
                
		c.add(panel1,BorderLayout.CENTER);
		
		panel2.setLayout( new GridLayout(1,1));
		panel2.add(register);
		

		c.add(panel2,BorderLayout.SOUTH);
		setSize(300,150);
                show();
        setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
	}
	public void actionPerformed(ActionEvent e)
	{
		if(e.getSource()==register)
		{
			this.dispose();
			new UserAdd();
		}
		else if(e.getSource()==CancelBtn)
		{			
			int n = JOptionPane.showConfirmDialog(
						this, "是否真的要退出", "退出窗口",
						JOptionPane.YES_NO_OPTION );
			if( n==JOptionPane.YES_OPTION )
				System.exit( 0 );

		}
		else if( e.getSource()==YesBtn )
		{
			
			String user_1=UserTextField.getText();
            String password_1=PasswordTextField.getText(); 
            
            if((user_1.length()==0)||(password_1.length()==0))
               {
               	System.out.println("用户名或密码不能为空！");
               }
	       /*数据库判断*/	
		   else
		     {
		     	try{
                   Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");//声明驱动程序
                   String url="jdbc:odbc:info";//指定数据源名
                   Connection con=DriverManager.getConnection(url);//连接数据库
            
               PreparedStatement select_stm=con.prepareStatement("select  密码 from 客户信息 where 帐户=?");
              //设置查询
               select_stm.setString(1,user_1);
              //设置查询中的一个参数
               ResultSet result=select_stm.executeQuery();
               //得到查询结果
                String temp_password=null;
                //声明存储查询结果中密码属性的变量
                if(result.next())
                temp_password=result.getString(1);
                //得到查询结果中密码属性值
                 result.close();
                if(temp_password==null)
                 //如果数据库中还没有此用户名
                 {
                  System.out.println(" no userId");
                  String s="this userId is not exits!";
                  JOptionPane.showMessageDialog(null,s);
                 }
                  
                 else if(password_1.regionMatches(0,temp_password,0,password_1.length()))
                 { 
               
                   dispose();  //让主窗口消失
			       new UserOP(UserTextField.getText());
                   
                 }
                 
			     con.close();
                }catch(Exception ev){}
                
               } 

		}
	}
	
	
	
	public static void main(String args[])
	{
		Login mainFrame=new Login();	
	}
}