login.java

基于目前许多中小型公司, 机关,中小学校,大学院系等都有自己的图书库, 供内部人员借阅。传统的手工登记办法

/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package libsystem;
/**
 * 
 * @author admin
 */
import java.awt.*;
import java.awt.event.*;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.*;
import java.sql.*;

/**
 * 登录窗口
 * @author admin
 */

public class Login extends JFrame
{
	private JPanel panel;
	private JLabel label0 = new JLabel();
	private JLabel accountlabel = new JLabel();
	private JLabel passwordlabel = new JLabel();
        private Connection conn;
        private Statement stmt;
        private ResultSet rs;
	private JTextField accountfield = new JTextField();
	private JPasswordField passwordfield = new JPasswordField();
	private JButton enterbut = new JButton();

	public Login()
	{   
            InitComponent();
            super.setVisible(true);
        }
        
        private void InitComponent(){ //初始化组件
	    panel = new JPanel();
	    panel.setLayout(null);
	    this.setTitle("图书馆管理系统　V1.0");
	    this.setBounds(300,200,400,300);
	    panel.setBackground(Color.black);

		label0.setText("登录信息");
		label0.setBounds(new Rectangle(155, 25, 200, 36));
		label0.setFont(new Font("Dialog", 1, 20));
		label0.setForeground(Color.white);
                
		accountlabel.setText("账号:");
		accountlabel.setBounds(new Rectangle(123, 85, 49, 16));
		accountlabel.setForeground(Color.white);
		passwordlabel.setText("密码:");
		passwordlabel.setBounds(new Rectangle(123, 122, 49, 16));
		passwordlabel.setForeground(Color.white);

		accountfield.setText("admin");
		accountfield.setBounds(new Rectangle(192, 85, 70, 18));
		passwordfield.setEchoChar('*');//返回要用于回显的字符。默认值为 '*'
		passwordfield.setText("123456");
		passwordfield.setBounds(new Rectangle(192, 122, 70, 18));

		enterbut.setText("进入系统");
		enterbut.setVisible(true);
		enterbut.setBounds(new Rectangle(150, 180, 101, 22));
		enterbut.setForeground(Color.white);
		enterbut.setBackground(Color.black);
                enterbut.addActionListener(new ActionListener (){
                    public void actionPerformed(ActionEvent e)
                        {
			String user = accountfield.getText().trim();
			String password = passwordfield.getText().trim();
      			/****判断用户输入的信息****/
      			if(user.equals("")|| password.equals(""))
      				JOptionPane.showMessageDialog(null, "账号或密码不能为空", "警告",
                                      JOptionPane.WARNING_MESSAGE);
      			else {
                    try {
                        /*从数据库中查询用户名(admin)和密码(admin)*/
                        stmt = ConnDataBase.getConnection().createStatement();
                        rs = stmt.executeQuery("select * from Account where ID='" + user + "' AND password='" + password + "'");
                        /*如果信息正确则进行以下操作*/
                        if (rs.next()) {
                            JOptionPane.showMessageDialog(null, "登陆成功");
                            new Console().addWindowListener(new WindowAdapter() {

                                public void windowClosing(WindowEvent e) {
                                    try {
                                        ConnDataBase.getConnection().close();
                                        System.exit(1);//退出程序用,dipose()只能关闭释放窗口,线程没结束
                                    } catch (SQLException ex) {
                                        System.out.println("无法断开连接");
                                        ex.printStackTrace();
                                    }
                                }
                            });
                            dispose();
                        } else {
                            JOptionPane.showMessageDialog(null, "账号或密码输入错误", "警告", JOptionPane.WARNING_MESSAGE);
                        }

                        accountfield.setText("");
                        passwordfield.setText("");
                    } catch (SQLException ex) {
                        Logger.getLogger(Login.class.getName()).log(Level.SEVERE, null, ex);
                    }
                    }
		}
	});
		panel.add(label0);
		panel.add(accountlabel);
		panel.add(passwordlabel);
		panel.add(accountfield);
		panel.add(passwordfield);
		panel.add(enterbut);
                super.add(panel);
        }//Init             
        

}