login.java

用java实现图书资料管理系统 操作系统：Windows 数据库：Windows Access 数据库 开发平台：NetBeans 开发语言：Java 语言

/*
 * login.java
 *
 * Created on 2007年12月19日, 上午6:42
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.ButtonGroup;
import java.sql.*;
import java.util.*;
import java.util.Date;

/**
 *
 * @author Owner
 */
public class login extends JPanel implements ActionListener
{
    userflag userflag;
    JTextField tid;
    JTextField tpassword;
    Box box1,box2,box3,basebox;
    JButton submit,reset;
    register regist;
    
    Connection con;
    Statement sql;
    ResultSet rs;
    /** Creates a new instance of login */
    public login(userflag userflag) {
        this.regist=regist;
        setLayout(null);
        this.userflag=userflag;
        submit=new JButton("确认");
        reset=new JButton("重设");
        submit.addActionListener(this);
        reset.addActionListener(this);
        tid=new JTextField(15);
        tpassword=new JTextField(15);
        box1=Box.createHorizontalBox();
        box1.add(new JLabel("用户名"));
        box1.add(Box.createHorizontalStrut(10));
        box1.add(tid);
        
        box2=Box.createHorizontalBox();
        box2.add(new JLabel("密码"));
        box2.add(Box.createHorizontalStrut(22));
        box2.add(tpassword);

        box3=Box.createHorizontalBox();
        box3.add(submit);
        box3.add(Box.createHorizontalStrut(20));
        box3.add(reset);
        
        basebox=Box.createVerticalBox();
        basebox.add(box1);
        basebox.add(Box.createVerticalStrut(10));
        basebox.add(box2);
        basebox.add(Box.createVerticalStrut(20));
        basebox.add(box3);
        add(basebox);
        basebox.setBounds(200,140,160,120);
    }
    
    public void actionPerformed(ActionEvent e)
    {
        if(e.getSource()==submit)
        {
            if(tid.getText().equals(""))
            {
                JOptionPane.showMessageDialog(this,"用户名不能为空");
            }
            else if(tpassword.getText().equals(""))
            {
                JOptionPane.showMessageDialog(this,"密码不能为空");
            }
            else 
            {
                try
                {
                    Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
                }
                catch(ClassNotFoundException e2){}
                try
                {
                    con=DriverManager.getConnection("jdbc:odbc:sample","std","123");
                    sql=con.createStatement();
                    String str="select * from user where id='"+tid.getText()+"' and password='"+tpassword.getText()+"'";
                    System.out.println(str);
                    rs=sql.executeQuery(str);
                    if(rs.next()==true)
                    {
                        System.out.println(tid.getText());
                        userflag.login(tid.getText());
                        JOptionPane.showMessageDialog(this,"已经登录");
                    }
                    else
                    {
                        JOptionPane.showMessageDialog(this,"没有此用户名或密码错误");
                    }
                }
                catch(SQLException e3)
                {
                    System.out.println("e3"+e3);
                }
            }
        }
        else if(e.getSource()==reset)
        {
            tid.setText(null);
            tpassword.setText(null);
        }
    }
}