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1、首先需要建立一個類,在這里,我命名為newLogin
newLogin類的代碼如下
package p4; import java.awt.Dimension; import java.awt.Font; import java.awt.Toolkit; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.sql.Connection; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Statement; import javax.swing.ButtonGroup; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JOptionPane; import javax.swing.JPasswordField; import javax.swing.JRadioButton; import javax.swing.JTextField; public class newLogin extends JFrame implements ActionListener{ private static final long serialVersionUID = 1L; private Connection con = null; private Statement statement = null; private ResultSet res = null; private ButtonGroup buttongroup = new ButtonGroup(); private MyPanel jp = new MyPanel(); private JLabel ul = new JLabel("用戶名:"); private JLabel pl = new JLabel("密 碼:"); private JLabel ts = new JLabel(""); private JTextField uname = new JTextField(); private JPasswordField pword = new JPasswordField(); private JRadioButton[] butArray = { new JRadioButton("學生",true), new JRadioButton("教師") }; private JButton login = new JButton("登陸"); private JButton reset = new JButton("重置"); public newLogin() { addListener(); initialFrame(); } private void initialFrame() { Font font = new Font("宋體",Font.BOLD,12); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setTitle("登陸"); jp.setLayout(null); ul.setBounds(100, 30, 60, 30); jp.add(ul); uname.setBounds(170, 30, 140, 30); jp.add(uname); pl.setBounds(100, 80, 60, 30); pword.setBounds(170, 80, 140, 30); jp.add(pl); jp.add(pword); ts.setBounds(100, 160, 200, 50); jp.add(ts); ts.setFont(font); login.setBounds(100, 220, 70, 30); jp.add(login); login.setFont(font); reset.setBounds(220, 220, 70, 30); jp.add(reset); reset.setFont(font); add(jp); setResizable(false); buttongroup.add(butArray[0]); buttongroup.add(butArray[1]); butArray[0].setBounds(120, 130, 100, 50); jp.add(butArray[0]); butArray[1].setBounds(220, 130, 100, 50); jp.add(butArray[1]); butArray[0].setContentAreaFilled(false); butArray[1].setContentAreaFilled(false); Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); int centerX = screenSize.width/2; int centerY = screenSize.height/2; int w = 427; int h = 331; setBounds(centerX-w/2, centerY-h/2, w, h); setVisible(true); uname.requestFocus(true); getContentPane().add(jp); jp.getRootPane().setDefaultButton(login); } private void addListener() { this.login.addActionListener(this); this.uname.addActionListener(this); this.pword.addActionListener(this); } @Override public void actionPerformed(ActionEvent e) { if(e.getSource() == uname) { pword.requestFocus(); } if(e.getSource() == pword) { butArray[0].requestFocus(); } if(e.getSource() == butArray[0]||e.getSource() == butArray[1]||e.getSource() == login) { // this.ts.setText("正在為您努力加載,請稍等......"); int type = this.butArray[0].isSelected()?0:1; String username = this.uname.getText().trim(); char[] p = this.pword.getPassword(); String password = String.valueOf(p).trim(); if(username.equals("")) { JOptionPane.showMessageDialog(this, "請輸入用戶名!","錯誤",JOptionPane.ERROR_MESSAGE); ts.setText(""); return ; } if(password.equals("")) { JOptionPane.showMessageDialog(this, "請輸入密碼!","錯誤",JOptionPane.ERROR_MESSAGE); ts.setText(""); return ; } try { con = new connection().getConnection(); //調用自己寫的一個數據庫連接類 statement = con.createStatement(); if(type == 0) { String sql = "select * from stuuser where "+ "username_stu='"+username+"'and password_stu='"+password+"'"; res = statement.executeQuery(sql); if(res.next()) { JOptionPane.showMessageDialog(this, "登錄成功!","提示",JOptionPane.INFORMATION_MESSAGE); this.dispose(); } else { JOptionPane.showMessageDialog(this, "用戶名或密碼錯誤!","錯誤",JOptionPane.ERROR_MESSAGE); ts.setText(""); uname.setText(""); pword.setText(""); } //關閉數據庫連接 if(res != null) { res.close(); } if(statement != null) { statement.close(); } if(con != null) { con.close(); } } else { String sql = "select * from teauser where "+ "username_tea='"+username+"'and password_tea='"+password+"'"; res = statement.executeQuery(sql); if(res.next()) { String spec_name = res.getString(1); JOptionPane.showMessageDialog(this, "登錄成功!","提示",JOptionPane.INFORMATION_MESSAGE); this.dispose(); } else { JOptionPane.showMessageDialog(this, "用戶名或密碼錯誤!","錯誤",JOptionPane.ERROR_MESSAGE); ts.setText(""); uname.setText(""); pword.setText(""); } //關閉數據庫連接 if(res != null) { res.close(); } if(statement != null) { statement.close(); } if(con != null) { con.close(); } } }catch(SQLException ea) { ea.printStackTrace(); } } else if(e.getSource() == reset) { uname.setText(""); pword.setText(""); } } }
2、編寫數據庫連接類,在這里命名為connection,然后在類里寫一個獲取連接的放回,并返回一個連接。
connection類的代碼如下:
package p4; import java.sql.Connection; import java.sql.DriverManager; //import java.sql.ResultSet; import java.sql.SQLException; //import java.sql.Statement; public class connection { private Connection con = null; // private Statement statement = null; // private ResultSet res = null; String driver = "com.mysql.cj.jdbc.Driver"; String url = "jdbc:mysql://localhost:3306/Stu_manager?serverTimezone=Asia/Shanghai"; String name = "root"; String passwd = "123456"; public connection() { } public Connection getConnection() { try{ Class.forName(driver).newInstance(); con = DriverManager.getConnection(url,name,passwd); }catch(ClassNotFoundException e){ System.out.println("對不起,找不到這個Driver"); e.printStackTrace(); }catch(SQLException e){ e.printStackTrace(); }catch(Exception e){ e.printStackTrace(); } return con; } }
3、在MySQL數據庫中需建立兩個用戶表,分別用來存儲不同用戶的登陸賬號和密碼,這里學生用戶表為stuuser,教師用戶表為teauser,建表的SQL語句如下:
stuuser表:
create table stuuser( username_stu varchar(20) primary key, password_stu char(20) not null, )ENGINE=InnoDB DEFAULT CHARSET=utf8;
teauser表:
create table teauser( username_tea varchar(20) primary key, password_tea char(20) not null, )ENGINE=InnoDB DEFAULT CHARSET=utf8;
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