login.java

Java 图书馆管理系统 Java 图书馆管理系统原代码,包括一些最基本的功能,非常实用.

/**
 * 
 */
package 图书馆;

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
/**
 * 
 * @author hp
 *
 * TODO To change the template for this generated type comment go to
 * Window - Preferences - Java - Code Style - Code Templates
 */
public class Login extends JFrame implements ActionListener {
	private JLabel JLb1;
	private JLabel JLb2;
	private JButton Ok_btn;
	private JButton Cancel_btn;
	private JTextField Jtfld1;
	private JPasswordField Jtfld2;
	private JFrame frame;
	private Connection con;
	private Statement stmt;
	private ResultSet result1;
	/**
	 * 构造函数
	 *
	 */
	public Login() {
		frame = new JFrame("登陆");
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		Container content = frame.getContentPane();
		/**
		 * content设置面板
		 */
		content.setLayout(new GridLayout(3, 2,20,20));
		/**
		 * 设置组件
		 */
		JLb1 = new JLabel("用户名:");
		JLb2 = new JLabel("密码:");
		Jtfld1 = new JTextField();
		Jtfld2 = new JPasswordField();
		
		Ok_btn = new JButton("确定");
		Cancel_btn = new JButton("取消");
		/**
		 * 事件监听
		 */
		Ok_btn.addActionListener(this);
		Cancel_btn.addActionListener(this);
		/**
		 * content添加组件
		 */
		content.add(JLb1);
		content.add(Jtfld1);
		content.add(JLb2);
		content.add(Jtfld2);
		content.add(Ok_btn);
		content.add(Cancel_btn);

		frame.setSize(250, 150);
		frame.setVisible(true);
		/**
		 * 加载驱动器
		 *连接数据库
		 * 设置数据源
		 */
		try {
			//加载驱动器
			Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
			//设置数据源
			con = DriverManager.getConnection("jdbc:odbc:demo");
			stmt = con.createStatement();

		} catch (ClassNotFoundException e) {
		} catch (SQLException ex) {
		}
	}
	/* *
	 * 事件处理
	 * (non-Javadoc)
	 * @see java.awt.event.ActionListener#actionPerformed(java.awt.event.ActionEvent)
	 */
	public void actionPerformed(ActionEvent e) {
		// TODO Auto-generated method stub
				String str1, str2, username, sqlStr;
				Object obj = e.getSource();
				str1 = Jtfld1.getText().trim();
				str2 = Jtfld2.getText().trim();
				try {
					/**
					 * 按钮Ok_btn的处理
					 */
					if (obj.equals(Ok_btn))

					{
						if (str1.equals("")|str2.equals("")) {
							JOptionPane.showMessageDialog(frame,
									"username or password is error!");
							return;
						}
						
						/**
						 * 连接表userziliao
						 *
						 */
						sqlStr = "select * from userziliao where 姓名=" + "'"
								+ str1 + "'" + " and 密码=" + "'" + str2 + "'";

						ResultSet result = stmt.executeQuery(sqlStr);
						if (result.next()) {
							//表的处理
							username = result.getString("姓名");
								new MainFrame();
								frame.dispose();
								stmt.close();
								con.close();
							}else if(!result.next()){
								JOptionPane.showMessageDialog(frame,"用户不存在,请注册!");	    
								frame.dispose();
							    new TransactCard();
								}
					
						} else if(obj.equals(Cancel_btn)){
							/**
							 * 按钮Cancel_btn的处理
							 */
							frame.dispose();
							stmt.close();
							con.close();
						}
				} catch (SQLException ex) {
					System.err.println(ex);
				}
			}
	/**
	 * 主函数
	 * @param args
	 */
	public static void main(String[] args) {
		javax.swing.SwingUtilities.invokeLater(new Runnable() {
			public void run() {
				new Login();
			}
		});
	}
}