landload.java

这是一个关于税务管理系统的java程序

import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.JOptionPane;
import java.sql.*;


public class landload {

	private JPasswordField passwordField;
	private JComboBox comboBox;
	private JTextField textField;
	private JFrame frame;

	/**
	 * Launch the application
	 * @param args
	 */
	public static Connection getConnection() throws SQLException,java.lang.ClassNotFoundException 
	{		                       
		String url="jdbc:mysql://localhost:3306/optimizesystem";
        Class.forName("com.mysql.jdbc.Driver");		        
        String userName="root";		
        String password="1234";		
        Connection con=DriverManager.getConnection(url, userName, password);	
        return con;			
    }		
	 
	public static void main(String args[]) {

          new landload().frame.setVisible(true);
          

	
	}
	/**
	 * Create the application
	 */
	public landload() {
		initialize();
	}

	/**
	 * Initialize the contents of the frame
	 */
	private void initialize() {
		frame = new JFrame("系统登陆");
		frame.getContentPane().setLayout(null);
		frame.setBounds(100, 100, 471, 339);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		final JLabel label = new JLabel();
		label.setFont(new Font("", Font.BOLD, 16));
		label.setText("系统用户登陆");
		label.setBounds(178, 50, 109, 22);
		frame.getContentPane().add(label);

		final JLabel label_1 = new JLabel();
		label_1.setFont(new Font("", Font.PLAIN, 14));
		label_1.setText("类   别：");
		label_1.setBounds(105, 110, 60, 15);
		frame.getContentPane().add(label_1);

		final JLabel label_2 = new JLabel();
		label_2.setFont(new Font("", Font.PLAIN, 14));
		label_2.setText("用户名：");
		label_2.setBounds(105, 145, 60, 15);
		frame.getContentPane().add(label_2);

		final JLabel label_3 = new JLabel();
		label_3.setFont(new Font("", Font.PLAIN, 14));
		label_3.setText("密   码：");
		label_3.setBounds(105, 180, 60, 15);
		frame.getContentPane().add(label_3);

		textField = new JTextField();
		textField.setBounds(190, 145, 109, 21);
		frame.getContentPane().add(textField);

		String ComboBoxStr[]={"系统管理员","系统操作员","用户"};
		comboBox = new JComboBox(ComboBoxStr);
		comboBox.setBounds(190, 110, 109, 21);
		frame.getContentPane().add(comboBox);

		passwordField = new JPasswordField();
		passwordField.setBounds(190, 180, 112, 21);
		frame.getContentPane().add(passwordField);

		final JButton button = new JButton();
		button.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent t) {
				int kind=(int)comboBox.getSelectedIndex()+1;
				String name=textField.getText();
				String pwd=passwordField.getText();
				try{
					    Connection con=getConnection();
				        Statement stmt=con.createStatement();
				        String query="select * from login where name='"+name+"' and password='"+pwd+"' and kind='"+kind+"'";
				        ResultSet rs=stmt.executeQuery(query);
				        if(name.equals("")&&pwd.equals(""))
						{
							Object[] options={"是（y）","否（n）","取消",};
							String str1=new String("警告！用户名或密码不能为空，请重新输入！");
							JOptionPane.showOptionDialog(null,str1,"警告窗口",JOptionPane.DEFAULT_OPTION,JOptionPane.WARNING_MESSAGE,null,options,options[0]);
						}
						else{
				        if(rs.next()){
					           int k=Integer.parseInt(rs.getString("kind"));
					           String n=rs.getString("name");
					           String p=rs.getString("password");
					           if((p.equals(pwd))&&(n.equals(name))&&(k==(kind))){
					        	   if(k==1)
					        	   {
					        		   managesystem window = new managesystem();
							           window.frame.setVisible(true);
					        	   }
					        	   if(k==2)
					        	   {
					        		   managesystem_1 window = new managesystem_1();
							           window.frame.setVisible(true);
					        	   }
					        	   if(k==3)
					        	   {
					        		   managesystem_2 window = new managesystem_2();
							           window.frame.setVisible(true);
					        	   }
					        	   else
					        	   {
					        		   return;
					        	   }
					    }
					    else{
						       Object[] options={"是（y）","否（n）","取消",};
						       String str1=new String("连接数据库失败！");
						       JOptionPane.showOptionDialog(null,str1,"失败窗口",JOptionPane.DEFAULT_OPTION,JOptionPane.WARNING_MESSAGE,null,options,options[0]);
					    }
				        }
				       else{
					         Object[] options={"是（y）","否（n）","取消",};
					         String str1=new String("警告！用户名或密码错误，请重新输入！");
					         JOptionPane.showOptionDialog(null,str1,"警告窗口",JOptionPane.DEFAULT_OPTION,JOptionPane.WARNING_MESSAGE,null,options,options[0]);
					         textField.setText(null);
					         passwordField.setText(null);
				       }
				rs.close();
				stmt.close();
				con.close();
				}
				}
			      catch(java.lang.ClassNotFoundException e){			    
				     	 System.err.print(" ClassNotFoundException: ");			         
				     	 System.err.println(e.getMessage());
				      }		
				      catch(SQLException ex){			                 
				     	 System.err.println(" SQLException: "+ex.getMessage());	
				      }	
					catch(Exception e) {
						e.printStackTrace();
					}
		}});
		button.setText("确定");
		button.setBounds(150, 245, 75, 23);
		frame.getContentPane().add(button);

		final JButton button_1 = new JButton();
		button_1.addActionListener(new ActionListener() {
			public void actionPerformed(ActionEvent arg0) {
				frame.dispose();
			}
		});
		button_1.setText("取消");
		button_1.setBounds(270, 245, 75, 23);
		frame.getContentPane().add(button_1);
	}

}