memberlogin.java

一个网吧登录系统

package com.hotdon.mem;
import java.awt.*;
import java.awt.event.*;
import java.sql.*;
import javax.swing.*;
public class memberLogin {
	//定义组件
	JFrame frame;
	JLabel lbAccount;
	JLabel lbPassword;
	JTextField textAccount;
	JPasswordField textPassword;
	JButton loginButton;
	public memberLogin(){
		//初始化组件
		frame=new JFrame("客户登录");
		lbAccount= new JLabel("账号");
		lbPassword= new JLabel("密码");
		textAccount= new JTextField(15);
		textPassword= new JPasswordField(8);		
		loginButton=new JButton("登录");
		//初始化布局
		Container contentPane=frame.getContentPane();
		contentPane.setLayout(new BorderLayout());
		JPanel panel= new JPanel();
		GridBagLayout gb=new GridBagLayout();
		panel.setLayout(gb);
		GridBagConstraints gbc= new GridBagConstraints();
		gbc.anchor=GridBagConstraints.WEST;
		gbc.insets= new Insets(2,2,2,2);
		panel.setBorder(BorderFactory.createTitledBorder(""));
		//使窗口们于中心
		Dimension screenSize=Toolkit.getDefaultToolkit().getScreenSize();
		Dimension frameSize=frame.getSize();
		if(frameSize.height>screenSize.height){
			frameSize.height=screenSize.height;
		}
		if(frameSize.width>screenSize.width){
			frameSize.width=screenSize.width;
		}
		frame.setLocation((screenSize.width - frameSize.width)/2,
				(screenSize.height - frameSize.height)/2);
		frame.setVisible(true);
		//添加组件到面板
		gbc.gridy=1;
		gbc.gridx=0;
		gb.setConstraints(lbAccount,gbc);
		panel.add(lbAccount,gbc);
		gbc.gridy=2;
		gbc.gridx=0;
		gb.setConstraints(lbPassword,gbc);
		panel.add(lbPassword,gbc);
		gbc.gridy=1;
		gbc.gridx=1;
		gb.setConstraints(textAccount,gbc);
		panel.add(textAccount,gbc);
		gbc.gridy=2;
		gbc.gridx=1;
		gb.setConstraints(textPassword,gbc);
		panel.add(textPassword,gbc);
		gbc.gridy=3;
		gbc.gridx=0;
		gb.setConstraints(loginButton,gbc);
		panel.add(loginButton,gbc);
		//”登录“按钮事件
		loginButton.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				if(! textAccount.getText().trim().equals("")&&
						!textPassword.getPassword().equals("")){
					dataDAO dao=null;
					dao=(com.hotdon.mem.dataDAO) new com.hotdon.dao.dataDAOImpl();
					try{
						String QueryString;
						QueryString="select * from memberTable";
						ResultSet rsl=dao.getData(QueryString);
						int flag1=0,flag2=1;
						while(rsl.next()){
							flag1++;
						}
						ResultSet rs=dao.getData(QueryString);
						while(rs.next()){
							String strTemp;
							if(rs.getString("memberID").equals(textAccount.getText())){
								flag2=0;
								if(rs.getString("password").equals(
										textPassword.getText())){
									String memberID;
									memberID=textAccount.getText();
									logform logframe= new logform(null,memberID);
									logframe.pack();
									logframe.setVisible(true);
									frame.setVisible(false);
									//使窗口位于中心
									Dimension screenSize;
									screenSize=Toolkit.getDefaultToolkit().getScreenSize();
									Dimension frameSize=logframe.getSize();
									if(frameSize.height>screenSize.height){
										frameSize.height=screenSize.height;
									}
									if(frameSize.width>screenSize.width){
										frameSize.width=screenSize.width;
									}
									logframe.setLocation((screenSize.width - 
											frameSize.width-10),(screenSize.height - 
													frameSize.height)-25);
									logframe.setVisible(true);			
							}
								else{
									//消息框代码
									final JDialog dialog= new JDialog((Frame)null,"错误",true);
									Container dialogContenPane=dialog.getContentPane();
									dialogContenPane.setLayout(new FlowLayout());
									dialogContenPane.add(new JLabel("密码不正确"));
									JButton jbutton= new JButton("正确");
									dialogContenPane.add(jbutton);
									jbutton.addActionListener(new ActionListener(){
										public void actionPerformed(ActionEvent e){
											dialog.dispose();
											textPassword.setText("");
										}
										});
									dialog.setBounds(450,300,100,90);
									dialog.setVisible(true);
									}
								   }
							if(flag2==0){
								break;
							}
							flag2++;//查找不到数据库,flag2标志加1
							if(flag2>flag1){
								//消息框代码
								final JDialog dialog= new JDialog((Frame) null,"错误",true);
								Container dialogContenPane=dialog.getContentPane();
								dialogContenPane.setLayout(new FlowLayout());
								dialogContenPane.add(new JLabel("用户不存在"));
								JButton jbutton= new JButton("确认");
								dialogContenPane.add(jbutton);
								jbutton.addActionListener(new ActionListener(){
									public void actionPerformed(ActionEvent e){
									dialog.dispose();
									textAccount.setText("");
									textPassword.setText("");						
								}
							});
								dialog.setBounds(450,300,100,90);
								dialog.setVisible(true);
								}
						}//while
					}//try
					catch(Exception exception){
						exception.printStackTrace();
					}
				}
				else{
					//消息框代码
					final JDialog dialog= new JDialog((Frame) null,"错误",true);
					Container dialogContenPane=dialog.getContentPane();
					dialogContenPane.setLayout(new FlowLayout());
					dialogContenPane.add(new JLabel("账号或密码不能为空"));
					JButton jbutton=new JButton("确认");
					dialogContenPane.add(jbutton);
					jbutton.addActionListener(new ActionListener(){
						public void actionPerformed(ActionEvent e){
							dialog.dispose();
						}
					});
					dialog.setBounds(450,300,130,90);
					dialog.setVisible(true);
				}
			}
		});
		//"退出“按钮事件
		gbc.gridy=3;
		gbc.gridx=1;
		JButton exitButton=new JButton("退出");
		panel.add(exitButton,gbc);
		exitButton.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
			frame.dispose();
		}
	});
contentPane.add(panel);
frame.pack();
frame.setVisible(true);
frame.addWindowListener(new WindowAdapter(){
	public void windowClosing(WindowEvent e){
		System.exit(0);
	}
});
}
public static void main(String[] args){
	SwingUtilities.invokeLater(new Runnable(){
		public void run(){
			try{
				UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
			}
			catch(Exception exception){
			exception.printStackTrace();
		}
		new memberLogin();
	}
   });
}
}