下面是按妳的要求寫的 現實界面的轉換 如果用戶名和密碼正確進入MyFrame1窗口 如果不正確進入MyFrame2窗口。
連數據庫的時候先添加數據庫驅動包，如果連接數據庫有問題 多打印壹下相關數據 很容易發現錯誤之處的
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.Statement;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import java.awt.Color;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
public class 登陸界面 extends JFrame {
private static final long serialVersionUID = 1L;
private JPasswordField passwordField;
private JTextField textField;
public static void main(String args[]) {
try {
登陸界面 frame = new 登陸界面();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* Create the frame
*/
public 登陸界面() {
super();
getContentPane().setLayout(null);
setBounds(100, 100, 500, 375);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
final JButton button = new JButton();
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String dir = "com.mysql.jdbc.Driver";//數據庫驅動類，我這是MySQL的 ，連數據庫記得導入驅動的jar包
Connection conn = null;
Statement stat = null;
ResultSet rs = null;
try{
Class.forName(dir);
String url = "jdbc:mysql://localhost:3306/hospital?user=root&password=root";//數據庫名 hospital用戶名和密碼都是root
conn = DriverManager.getConnection(url);
stat = conn.createStatement();
//得到用戶名
String name = textField.getText().trim();
//得到密碼
char[] pass = passwordField .getPassword();
String password = new String(pass);
//輸出用戶名密碼
System.out.println(name);
System.out.println(password);
//數據庫表user,字段用戶名為username,密碼password,都是varchar型
String sql = "select username,password from user where username = '" + name + "'";
rs = stat.executeQuery(sql.toString());
if(rs.next()){
//獲得數據庫裏面的用戶名和密碼
String sname = rs.getString("username");
String spass = rs.getString("password");
//對輸入的用戶名和密碼和數據庫裏的進行判斷
if((rs != null ) && (name.equals(sname)) && (password.equals(spass))) {
//登陸成功釋放登陸界面資源，顯示a窗口
登陸界面.this.dispose();
new MyFrame1().launch();
System.out.println("chenggong");
} else {
//密碼錯誤，顯示b窗口
登陸界面.this.dispose();
new MyFrame2().launch();
System.out.println("mimacuowu");
}
} else {
//用戶名錯誤和其他情況，顯示b窗口
登陸界面.this.dispose();
new MyFrame2().launch();
System.out.println("yonghumingcuowu");
}
}catch(Exception e1){
//數據庫連接失敗，顯示b窗口
登陸界面.this.dispose();
new MyFrame2().launch();
System.out.println("數據庫連接錯誤");
}finally{
try{
if(rs!=null) rs.close();
if(stat!=null) stat.close();
if(conn!=null) conn.close();
}catch(Exception e1){
}
}
}
});
button.setText("確定");
button.setBounds(62, 273, 101, 25);
getContentPane().add(button);
final JButton button_1 = new JButton();
button_1.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {System.exit(0);
}
});
button_1.setText("取消");
button_1.setBounds(325, 273, 101, 25);
getContentPane().add(button_1);
final JLabel label = new JLabel();
label.setText("用戶名");
label.setBounds(23, 60, 60, 15);
getContentPane().add(label);
final JLabel label_1 = new JLabel();
label_1.setText("密碼");
label_1.setBounds(23, 172, 60, 15);
getContentPane().add(label_1);
textField = new JTextField();
textField.setBounds(48, 115, 90, 21);
getContentPane().add(textField);
passwordField = new JPasswordField();
passwordField.setBounds(42, 216, 96, 25);
getContentPane().add(passwordField);
}
}
class MyFrame1 extends Frame {
int orgX1;
int orgY1;
int orgX2;
int orgY2;
public void launch() {
setBounds(500,500,500,500);
setVisible(true);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
e.getWindow().dispose();
System.exit(0);
}
});
}
public void paint(Graphics g) {
//Color c =g.getColor();
g.setColor(Color.red);
g.drawLine(100, 50, 100, 80);
}
}
class MyFrame2 extends Frame {
int orgX1;
int orgY1;
int orgX2;
int orgY2;
public void launch() {
setBounds(500,500,500,500);
setVisible(true);
addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
e.getWindow().dispose();
System.exit(0);
}
});
}
public void paint(Graphics g) {
//Color c =g.getColor();
g.setColor(Color.red);
g.draw3DRect(100, 100, 100, 100,true);
}
}