loginframe.java

java选课系统管理端

//以下是布局GUI的类
//package myprojects.main;
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; 
   public static JTextField userNameTextField;//声明登陆名为全局变量
   private JPasswordField passwordField;
   private JComboBox 登陆列表;
   private String[] 登陆模式;
   private int    login = 0 ;
   private static String 登陆类型="学生登陆";
   
   
   public LoginFrame() 
   {
		
	    setTitle("登录窗口");
    	setSize(300,200);
      	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("用户帐号");
        
        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("登陆口令");
        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);

        String[] 登陆模式 ={"学生登陆","教师登陆","系统维护"}; 
        登陆列表 = new JComboBox(登陆模式);
        登陆列表.setPreferredSize(new Dimension(120, 25));
        JLabel loginLabel = new JLabel();
        loginLabel.setText("登陆类型");
        loginLabel.setLabelFor(登陆列表);
        //判断登陆类型，以便进入不同的用户界面
        登陆列表.addActionListener(new ActionListener() 
        {
            public void actionPerformed(ActionEvent event) 
            {
            	登陆类型 = (String)登陆列表.getSelectedItem();
               // System.out.println(登陆类型);
                
            }
        });  
       
        constraints.gridx = 0;
        constraints.gridy = 2;
        constraints.gridwidth = 1;
        constraints.gridheight = 1;
        contents.add(loginLabel, constraints);

        // 登陆模式
       
        constraints.gridx = 1;
        constraints.gridy = 2;
        constraints.gridwidth = 2;
        constraints.gridheight = 1;
        contents.add(登陆列表, constraints);

        
        JPanel buttonPanel = createButtonPanel(); // sets global loginButton
        constraints.gridx = 0;
        constraints.gridy = 3;
        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)
               	{
               	   if(登陆类型.equals("教师登陆"))
               	   {
               	   	  JFrame f=new TeacherFrame();
                      f.show();
               		  dispose();
                   }
                   else if(登陆类型.equals("系统维护"))
                   {
                   	  JFrame f=new ManagerFrame();
                      f.show();
               	  	  dispose();
                   }
                   else     //(登陆类型.equals("学生登陆"))
               	   {
               		  JFrame f=new StudentFrame();
                      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);
        buttons.removeAllElements(); // simplify gc

        return panel;
    } // createButtonPanel()
    
     private void initAboutDialog()
     {
		JOptionPane.showMessageDialog( this,"应用数学系2002级信息管理与信息系统\n 黄振威","关于作者",JOptionPane.INFORMATION_MESSAGE ); 
        	return; 
     }
     private void logindispose() 
     {
     	String url = "jdbc:odbc:java"; //数据源名字为java
    	String username = "sa"; 
    	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 ) 
      	{ 
         	JOptionPane.showMessageDialog ( this ,cnfex ,
              "学生选课管理系统",JOptionPane.WARNING_MESSAGE ); 
         	System.exit( 1 );  // terminate program 
      	} 
      	//捕获连接数据库异常
      	catch ( SQLException sqlex ) 
      	{ 
         	//sqlex.printStackTrace();
         	JOptionPane.showMessageDialog ( this ,"无法连接到SQL SERVER ，\n请确认SQL SERVER是否运行\n或数据源设置是否正确！ " ,
          "学生选课管理系统",JOptionPane.WARNING_MESSAGE );  
         	System.exit( 1 );  // terminate program 
      	} 
     	
     	try
     	{
     		String loginquery;
     		String loginusename = userNameTextField.getText();
         	String loginpassword = passwordField.getText();
         	if(userNameTextField.getText().equals( "" ))
   	        {
   	             JOptionPane.showMessageDialog( this,"用户名必须为字母、数字和、汉字\n及其组合，不允许为空格键.",
   	                                     "登陆 ",JOptionPane.WARNING_MESSAGE ); 
                 //setTitle( "无记录显示" ); 
                 return; 	
   	        }
         	if(登陆类型.equals("教师登陆"))
   			   loginquery = "SELECT * FROM 教师表 WHERE(登陆帐号='"+loginusename +"' AND 登陆密码 ='"+loginpassword+"')";	
   			else if(登陆类型.equals("系统维护"))
   			   loginquery = "SELECT * FROM 管理员 WHERE(用户名='"+loginusename +"' AND 密码 ='"+loginpassword+"')";			  
   			else //(登陆类型.equals("学生登陆"))
         	   loginquery = "SELECT * FROM 学生基本信息表 WHERE(学号='"+loginusename +"' AND 密码 ='"+loginpassword+"')";
   			loginstatement = loginconnection.createStatement(); 
        	loginresultSet = loginstatement.executeQuery( loginquery ); 
        	boolean Records = loginresultSet.next();
        	if ( ! Records ) 
      		{ 
        		JOptionPane.showMessageDialog( this,"没有此用户或密码错误" ); 
        		//return; 
      		} 
      		else
      		{
      			login = 1 ;	
      		}
      		loginconnection.close();
        }
     	catch(SQLException sqlex)
     	{
     		//sqlex.printStackTrace();
     		JOptionPane.showMessageDialog ( this ,sqlex ,
          "学生选课管理系统",JOptionPane.WARNING_MESSAGE ); 
     	}
    }
}