loginframe.java

这是一个JAVA开发的商场VIP消费管理系统

//
//以下是布局GUI的类
//
import java.sql.*;
import java.io.*;
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.border.*;
import javax.swing.table.*;

class LoginFrame extends JFrame 
{
   private JButton loginButton ;
   private Connection loginconnection;
   private Statement loginstatement; 	
   private ResultSet loginresultSet; 
   
   private JTextField userNameTextField;
   private JPasswordField passwordField;
   
   private int    login = 0 ;
   
   public LoginFrame() 
   {
		//loginconnection = connection ;
	setTitle("登录窗口");
    	setSize(250,150);
      	setResizable(false);
      	addWindowListener(new WindowAdapter() 
      	{
        	public void windowClosing(WindowEvent e) 
        	{
            	System.exit(0);
        	}
      	});
      	setLocation(350,200);
      	
      	GridBagLayout layout = new GridBagLayout();
        Container contents = getContentPane();
        contents.setLayout(layout);
        
        GridBagConstraints constraints = new GridBagConstraints();
        
        userNameTextField = new JTextField(); //needed below
        userNameTextField.setPreferredSize(new Dimension(120, 25));
        // user name label
        JLabel userNameLabel = new JLabel();
        //userNameLabel.setDisplayedMnemonic("用户名");
        userNameLabel.setLabelFor(userNameTextField);
        userNameLabel.setText("用户名");
        
        constraints.weightx = 100;
        constraints.weighty = 100;
        constraints.gridx = 0;
        constraints.gridy = 0;
        constraints.gridwidth = 1;
        constraints.gridheight = 1;
        contents.add(userNameLabel, constraints);
        
        constraints.gridx = 1;
        constraints.gridy = 0;
        constraints.gridwidth = 2;
        constraints.gridheight = 1;
        contents.add(userNameTextField, constraints);
        
        passwordField = new JPasswordField(); // needed below
        passwordField.setPreferredSize(new Dimension(120, 25));
        // password label
        JLabel passwordLabel = new JLabel();
        
        passwordLabel.setText("口  令");
        passwordLabel.setLabelFor(passwordField);

        constraints.gridx = 0;
        constraints.gridy = 1;
        constraints.gridwidth = 1;
        constraints.gridheight = 1;
        contents.add(passwordLabel, constraints);

        // password field
       
        constraints.gridx = 1;
        constraints.gridy = 1;
        constraints.gridwidth = 2;
        constraints.gridheight = 1;
        contents.add(passwordField, constraints);
        
        JPanel buttonPanel = createButtonPanel(); // sets global loginButton
        constraints.gridx = 0;
        constraints.gridy = 2;
        constraints.gridwidth = 3;
        constraints.gridheight = 1;
        contents.add(buttonPanel, constraints);
   }
   
    private JPanel createButtonPanel() 
    {

        JPanel panel = new JPanel();
        panel.setLayout(new BoxLayout(panel, 0));

        // login button (global variable)
        loginButton = new JButton();
        loginButton.setText("确  定");
        loginButton.addActionListener(new ActionListener() 
        {
            public void actionPerformed(ActionEvent event) 
            {
               	logindispose();
               	if(login == 1)
               	{
               		JFrame f = new MainFrame();
               		f.show();
               		dispose();
               	}
            }
        });
        panel.add(loginButton);

        // space
        panel.add(Box.createRigidArea(new Dimension(5,0)));

        // cancel button
        JButton cancelButton = new JButton();
        cancelButton.setText("取  消");
        cancelButton.addActionListener(new ActionListener() 
        {
            public void actionPerformed(ActionEvent event) 
            {
                dispose();
                System.exit(0);
            }
        });
        panel.add(cancelButton);

        // space
        panel.add(Box.createRigidArea(new Dimension(5,0)));

        // help button
        JButton helpButton = new JButton();
        helpButton.setText("About");
        helpButton.addActionListener(new ActionListener() 
        {
            public void actionPerformed(ActionEvent event) {
                initAboutDialog();
            }
        });
        panel.add(helpButton);

        Vector buttons = new Vector(3);
        buttons.add(cancelButton);
        buttons.add(helpButton);
        buttons.add(loginButton);
        equalizeComponentSizes(buttons);
        buttons.removeAllElements(); // simplify gc

        return panel;
    } // createButtonPanel()
    
     private void equalizeComponentSizes(java.util.List components) 
     {

        // Get the largest width and height
        int i = 0;
        Dimension maxPreferred = new Dimension(0,0);
        JComponent oneComponent = null;
        Dimension thisPreferred = null;
        for (i = 0; i < components.size(); ++i) {
            oneComponent = (JComponent)components.get(i);
            thisPreferred = oneComponent.getPreferredSize();
            maxPreferred.width =
                Math.max(maxPreferred.width, (int)thisPreferred.getWidth());
            maxPreferred.height =
                Math.max(maxPreferred.height, (int)thisPreferred.getHeight());
        }

        // reset preferred and maximum size since BoxLayout takes both
        // into account
        for (i = 0; i < components.size(); ++i) {
            oneComponent = (JComponent)components.get(i);
            oneComponent.setPreferredSize((Dimension)maxPreferred.clone());
            oneComponent.setMaximumSize((Dimension)maxPreferred.clone());
        }
    } // equalizeComponentSizes()
    
    private void windowAction() 
    {
    	JFrame MainFrame = new JFrame();
        MainFrame.setSize(new Dimension(550,350));
        MainFrame.show();
        
        setVisible(false);
        dispose();
    }
     private void initAboutDialog()
     {
		JDialog dialog = new About(this,true);
        dialog.show();      
     }
     private void logindispose() 
     {
     	String url = "jdbc:odbc:VipQuery"; 
    	String username = ""; 
    	String password = ""; 
    	//加载驱动程序以连接数据库
      	try 
      	{ 
        	Class.forName( "sun.jdbc.odbc.JdbcOdbcDriver" ); 
        	loginconnection = DriverManager.getConnection( url, username, password ); 
      	} 
      	//捕获加载驱动程序异常
      	catch ( ClassNotFoundException cnfex ) 
      	{ 
        	System.err.println("装载 JDBC/ODBC 驱动程序失败。" ); 
        	cnfex.printStackTrace(); 
         	System.exit( 1 );  // terminate program 
      	} 
      	//捕获连接数据库异常
      	catch ( SQLException sqlex ) 
      	{ 
         	System.err.println( "无法连接数据库" ); 
         	sqlex.printStackTrace(); 
         	System.exit( 1 );  // terminate program 
      	} 
     	
     	try
     	{
     		String loginquery;
     		String loginusename = userNameTextField.getText();
         	String loginpassword = passwordField.getText();
         	
         	loginquery = "select * from UESR_MANAGER where (用户名='"+loginusename +
   							  "' and	用户口令 = '"+loginpassword+"')";
   							  
   			loginstatement = loginconnection.createStatement(); 
        	loginresultSet = loginstatement.executeQuery( loginquery ); 
        	boolean Records = loginresultSet.next();
        	if ( ! Records ) 
      		{ 
        		JOptionPane.showMessageDialog( this,"登录失败" ); 
        		return; 
      		} 
      		else
      		{
      			login = 1 ;	
      		}
      		loginconnection.close();
        }
     	catch(SQLException sqlex)
     	{
     		sqlex.printStackTrace();
     	}	
     }
}