loginintosystem.java

这是一个简单的图书管理系统,适用于教学中演示,讲解java高级编程语言

package lib_source;
import javax.swing.*;

import java.awt.*;
import java.awt.event.*;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;

import javax.swing.border.*;

public class LoginIntoSystem extends JFrame implements ActionListener {
	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	public static final int WIDTH = 380;
	public static final int HEIGHT = 345;
	private JTextField text;
	private JPasswordField password;
	public LoginIntoSystem() {
		setTitle("身份验证");
		setSize(WIDTH, HEIGHT);
		setResizable(false);
		setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
		addWindowListener(new WindowAdapter() {
			public void windowClosing(WindowEvent e) {
				dispose();
			}
		});
		Container content = getContentPane();
		JPanel jPanel;
		jPanel = new JPanel();
		jPanel.setLayout(new FlowLayout());
		jPanel.setBorder(new BevelBorder(BevelBorder.RAISED));
        JLabel myLabel;
        myLabel=new JLabel(new ImageIcon(ClassLoader.getSystemResource("images/tree002.jpg")),JLabel.CENTER);
     
        jPanel.add(myLabel);
        JPanel panel;
		JLabel[] label = new JLabel[2];
		String[] str1 = { "操作员号码", "操作员口令" };
		String[] str3={"images/超级QQ.JPG","images/心心相约.jpg"};
		for (int i = 0; i < 2; i++) {
			panel = new JPanel();
			panel.setLayout(new FlowLayout());
			panel.setBorder(new BevelBorder(BevelBorder.RAISED));
			panel.add(new JLabel(new ImageIcon(ClassLoader.getSystemResource(str3[i])),JLabel.CENTER));
			label[i] = new JLabel(str1[i]);
			panel.add(label[i]);
			if (i == 0) {
				text = new JTextField(15);
				text.setBorder(new BevelBorder(BevelBorder.LOWERED));
				panel.add(text);
			} else if (i == 1) {
				password = new JPasswordField(15);
			//	password.setEchoChar('&');
				password.setBorder(new BevelBorder(BevelBorder.LOWERED));
				panel.add(password);
			}
			jPanel.add(panel);
		}
		JPanel buttonPanel = new JPanel();
		buttonPanel.setLayout(new FlowLayout());
		buttonPanel.setBorder(new BevelBorder(BevelBorder.RAISED));
		String[] str2 = { "确定", "取消","返回" };
		JButton[] button;
		button = new JButton[str2.length];
		buttonPanel.add(new JLabel(new ImageIcon(ClassLoader.getSystemResource("images/天使我的爱.jpg")),JLabel.CENTER));
		for(int i = 0; i < str2.length; i++){
			button[i] = new JButton(str2[i]);
			button[i].addActionListener(this);
			buttonPanel.add(button[i]);
		}
		buttonPanel.add(new JLabel(new ImageIcon(ClassLoader.getSystemResource("images/心的守候.jpg")),JLabel.CENTER));
		jPanel.add(buttonPanel);
		content.add(jPanel);
		setVisible(true);
		Dimension screen = getToolkit().getScreenSize();
		setLocation((screen.width - getSize().width) / 2,
				(screen.height - getSize().height) / 2);
	
	}
	public void actionPerformed(ActionEvent e) {
		String s = new String(password.getPassword());
		String s1=LibraryManagementSystem.str;
		if (e.getActionCommand().equals("取消")) {
			dispose();
			}
		else if (e.getActionCommand().equals("返回")) {
			dispose();
			new LibraryManagementSystem().setVisible(true);
		} 
		else if (e.getActionCommand().equals("确定")) {
			if (text.getText().equals("") || s.equals("")) {
				JOptionPane.showMessageDialog(LoginIntoSystem.this, "   用户名或密码不能为空");
			}
			else{
			 String dbURL = "jdbc:odbc:Student2007";
			 String user = "devon";
		 String pw = "book";
		 String s2="";
		 try	{
				Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");  
				Connection con=DriverManager.getConnection(dbURL,user,pw); 
	
				Statement st=con.createStatement(); 
				ResultSet rs=st.executeQuery("select * from Administer where  帐号 ='"+text.getText()+"' and 口令 = '"+s+"'"); 
				
				if (rs.next()){ 
					
					s2=rs.getString("权限级别");
					if (s1.equals("图书流通")) {
						dispose();
						new BookFlow().setVisible(true);
					} else if (s1.equals("系统操作")&(s2.equals("管理员"))) {
					     dispose();
						 new SystemOperation().setVisible(true);
					}else if (s1.equals("系统操作")&!s2.equals("管理员")) {
						JOptionPane.showMessageDialog(LoginIntoSystem.this,"对不起,您输入的信息不正确,只有管理员才能进行系统操作.");	
					}	
				}
				else JOptionPane.showMessageDialog(LoginIntoSystem.this,"您输入的信息不正确,请输入正确用户名或密码");		
				con.close(); 
			}
			catch(Exception ex){
				JOptionPane.showMessageDialog(LoginIntoSystem.this,"数据库连接错误!\n"+ex);	
			ex.printStackTrace(); 
			}
		}
	}

			 
 }
	public static void main(String args[]){
		new LoginIntoSystem();
	}
}