**您好。我有关于登录系统的这个问题。这是场景：我有2个JFrame。 JFrame1用于登录，JFrame2用于提供信息。用户名，密码和个人信息包含在数据库中。如果Employee1登录，则第二个JFrame应该显示有关Employee 1的信息。我尝试创建一个sql语句，但我不知道如何使用jFrame1中的输入文本作为参考，以便在JFrame2中显示信息。 这是登录时的代码（JFrame1）：
import java.sql.*;
import javax.swing.*;
public class LoginForm extends javax.swing.JFrame {
Connection conn = null;
PreparedStatement pst = null;
ResultSet rs = null;
/**
* Creates new form EmployeeHome1
*/
public LoginForm() {
initComponents();
conn = dbconnect.ConnectDB();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jLabel3 = new javax.swing.JLabel();
username = new javax.swing.JTextField();
password = new javax.swing.JPasswordField();
b_login = new javax.swing.JButton();
jLabel4 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("Employee Payroll System - Log In");
setMinimumSize(new java.awt.Dimension(400, 310));
setResizable(false);
getContentPane().setLayout(null);
jLabel1.setFont(new java.awt.Font("Always In My Heart", 0, 48)); // NOI18N
jLabel1.setForeground(new java.awt.Color(255, 255, 255));
jLabel1.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel1.setText("Employee Payroll System");
getContentPane().add(jLabel1);
jLabel1.setBounds(-10, 20, 400, 61);
jLabel2.setFont(new java.awt.Font("Arial Narrow", 0, 18)); // NOI18N
jLabel2.setForeground(new java.awt.Color(255, 255, 255));
jLabel2.setText("username :");
getContentPane().add(jLabel2);
jLabel2.setBounds(59, 122, 73, 21);
jLabel3.setFont(new java.awt.Font("Arial Narrow", 0, 18)); // NOI18N
jLabel3.setForeground(new java.awt.Color(255, 255, 255));
jLabel3.setText("password :");
getContentPane().add(jLabel3);
jLabel3.setBounds(59, 167, 70, 21);
username.setFont(new java.awt.Font("Arial Narrow", 0, 18)); // NOI18N
username.setHorizontalAlignment(javax.swing.JTextField.CENTER);
getContentPane().add(username);
username.setBounds(171, 119, 170, 27);
password.setFont(new java.awt.Font("Arial Narrow", 0, 18)); // NOI18N
password.setHorizontalAlignment(javax.swing.JTextField.CENTER);
getContentPane().add(password);
password.setBounds(171, 164, 170, 27);
b_login.setFont(new java.awt.Font("Arial Narrow", 0, 18)); // NOI18N
b_login.setText("Log In");
b_login.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
b_loginMouseClicked(evt);
}
});
getContentPane().add(b_login);
b_login.setBounds(159, 229, 71, 29);
jLabel4.setHorizontalAlignment(javax.swing.SwingConstants.CENTER);
jLabel4.setIcon(new javax.swing.ImageIcon(getClass().getResource("/Blue_Background.jpg"))); // NOI18N
getContentPane().add(jLabel4);
jLabel4.setBounds(0, 0, 400, 310);
getAccessibleContext().setAccessibleName("");
pack();
}// </editor-fold>
private void b_loginMouseClicked(java.awt.event.MouseEvent evt) {
// TODO add your handling code here:
String sql = "select * from tbl_login where username = '"+username.getText()+"' and password = '"+password.getText()+"'";
try {
pst = conn.prepareStatement(sql);
rs = pst.executeQuery();
if (rs.next()){
newform();
username.getText
username
}
else {
JOptionPane.showMessageDialog(null, "Incorrect username or password.");
}
}
catch (Exception e){
JOptionPane.showMessageDialog(null, e);
}
}
public void newform(){
String sql1 = "select type from tbl_login where username='"+username.getText()+"' and password='"+password.getText()+"'";
try {
pst = conn.prepareStatement(sql1);
rs = pst.executeQuery();
rs.next();
String name = rs.getString("type");
if (name.equals("admin")) {
AdminHome ah = new AdminHome();
ah.setVisible(true);
}
else {
EmployeeHome eh = new EmployeeHome();
eh.setVisible(true);
}
}
catch (Exception e){
JOptionPane.showMessageDialog(null, e);
}
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(LoginForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(LoginForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(LoginForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(LoginForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new LoginForm().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton b_login;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JPasswordField password;
private javax.swing.JTextField username;
// End of variables declaration
}
我唯一关注的是EmployeeHome（JFrame2）。它应显示登录系统的员工的信息。请尽快帮助我。提前谢谢： - ）
答案 0 :(得分：0)
基本上，当您创建新框架时，您需要将其引用传递给您想要提供的信息。
就个人而言，我会创建一个Session或User对象，该对象封装了数据库中有关当前登录用户的信息。这意味着您不需要持续访问数据库。
例如......
if (rs.next) {
// Create a new user from the result set....
User user = createUser(rs);
if ("admin".equals(user.getType()) {
AdminHome ah = new AdminHome(user);
ah.setVisible(true);
} else {
EmployeeHome eh = new EmployeeHome(user);
eh.setVisible(true);
}
}