我正在尝试在 Java Netbeans IDE 中运行对我的桌面应用程序的数据代码的修改,但问题是在某人有权访问修改数据之前,我想确保该人通过提供用户名和另一个 JFrame 表单中的密码。如果用户名和密码验证通过,则修改任务才会成功;否则用户将收到身份验证失败的错误。我尝试在主表单中编写代码,但是当我想在身份验证表单的 button_click 事件中编写代码时,可以吗?我尝试过,但它说你需要在此类中声明该类的变量,请提供帮助..??
这是登录表单,我想用它来验证用户是否修改数据,一旦验证用户,我想允许他运行修改部分......
private void loginActionPerformed(java.awt.event.ActionEvent evt) {
if(evt.getSource()==login){
if((tb_uid.getText().equals(""))||(tb_pwd.getText().equals(""))){
JOptionPane.showMessageDialog(rootPane, "Please Enter Valid UserName and Password!");
}else{
DBUtil util = new DBUtil();
String user1 = "";
String pass1 = "";
try {
Connection con = util.getConnection();
PreparedStatement stmt = con.prepareStatement("SELECT * FROM login where username=?");
ResultSet res;
String value1 = tb_uid.getText();
String value2 = tb_pwd.getText();
stmt.setString(1, "" + (value1));
res = stmt.executeQuery();
while (res.next()) {
user1 = res.getString("username");
pass1 = res.getString("password");
}
if (value1.equals(user1) && value2.equals(pass1)) {
JOptionPane.showMessageDialog(null, "AUTHENTICATION SUCCESSFUL!");
try {
Connection con = util.getConnection();
PreparedStatement stmtn = con.prepareStatement("update soil_det set[weight]=?,[note_state]=?,[dm_state]=?,[1]=?,[2]=?,[5]=?,[10]=?,[20]=?,[50]=?,[100]=?,[500]=?,[1000]=? FROM [CNV].[dbo].[soil_det] where rm_id=? and box_no =?");
String rmn = (tf_rm_id.getText() == null || tf_rm_id.getText().equals("")) ? "0" : tf_rm_id.getText();
String an = (txtRe1.getText().trim() == null || txtRe1.getText().equals("")) ? "0" : txtRe1.getText();
String bn = (txtRs2.getText().trim() == null || txtRs2.getText().equals("")) ? "0" : txtRs2.getText();
String cn = (txtRs5.getText().trim() == null || txtRs5.getText().equals("")) ? "0" : txtRs5.getText();
String dn = (txtRs10.getText().trim() == null || txtRs10.getText().equals("")) ? "0" : txtRs10.getText();
String en = (txtRs20.getText().trim() == null || txtRs20.getText().equals("")) ? "0" : txtRs20.getText();
String fn = (txtRs50.getText().trim() == null || txtRs50.getText().equals("")) ? "0" : txtRs50.getText();
String gn = (txtRs100.getText().trim() == null || txtRs100.getText().equals("")) ? "0" : txtRs100.getText();
String hn = (txtRs500.getText().trim() == null || txtRs500.getText().equals("")) ? "0" : txtRs500.getText();
String in = (txtRs1000.getText().trim() == null || txtRs1000.getText().equals("")) ? "0" : txtRs1000.getText();
String bnn = (txtboxno.getText().trim() == null || txtboxno.getText().equals("")) ? "0" : txtboxno.getText();
String bwn = (txtboxwgt.getText().trim() == null || txtboxwgt.getText().equals("")) ? "0" : txtboxwgt.getText();
Object nsn = (cbnotstat.getSelectedItem() == null || cbnotstat.getSelectedItem().equals("")) ? "0" : cbnotstat.getSelectedItem();
Object dsn = (cbdmnstat.getSelectedItem() == null || cbdmnstat.getSelectedItem().equals("")) ? "0" : cbdmnstat.getSelectedItem();
stmtn.setString(1, "" + (bwn));
stmtn.setString(2, "" + nsn);
stmtn.setString(3, "" + dsn);
stmtn.setInt(4, Integer.parseInt(an));
stmtn.setInt(5, Integer.parseInt(bn));
stmtn.setInt(6, Integer.parseInt(cn));
stmtn.setInt(7, Integer.parseInt(dn));
stmtn.setInt(8, Integer.parseInt(en));
stmtn.setInt(9, Integer.parseInt(fn));
stmtn.setInt(10, Integer.parseInt(gn));
stmtn.setInt(11, Integer.parseInt(hn));
stmtn.setInt(12, Integer.parseInt(in));
stmtn.setString(13, "" + (rmn));
stmtn.setInt(14, Integer.parseInt(bnn));
} catch (Exception ex) {
JOptionPane.showMessageDialog(null, ex.getMessage());
}
}
else {
JOptionPane.showMessageDialog(this, "AUTHERNTICATION UNSUCCESSFUL", "Error", JOptionPane.ERROR_MESSAGE);
}
} catch (Exception ex) {
JOptionPane.showMessageDialog(null, ex.getMessage());
}
this.dispose();
}
}
}
但主要问题是来自另一种形式的修改部分..
最佳答案
这是一个 SSCCE,您可以测试一下,看看这是否是您想要的功能。我首先创建登录 JFrame,要求用户输入其凭据。然后,为了将该信息传递给另一个类,我将 Login 类的整个实例传递给新类 (OtherClass)。我在 Login 中有访问器方法,将在 OtherClass 中使用该方法来检索已存储在字符串中的 JTextField 信息。如果您不传递整个 Login 类,即使您使用 getText() 将 JTextField 内容存储在字符串中,也无法使用访问器方法访问该信息。
import javax.swing.JTextField;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JButton;
import javax.swing.JLabel;
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.SwingUtilities;
public class Login extends JFrame
{
private static final int FRAME_WIDTH = 250;
private static final int FRAME_HEIGHT = 100;
private JPanel labelPanel;
private JPanel textPanel;
private JTextField userName;
private JTextField userPassword;
private JButton loginButton;
private String userNameString;
private String userPasswordString;
public Login()
{
super("Please Login");
setSize(FRAME_WIDTH, FRAME_HEIGHT);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setLayout(new BorderLayout());
labelPanel = new JPanel();
labelPanel.setLayout(new GridLayout(2, 1));
add(labelPanel, BorderLayout.WEST);
JLabel userLabel = new JLabel("User Name: ");
labelPanel.add(userLabel);
JLabel passwordLabel = new JLabel("Password: ");
labelPanel.add(passwordLabel);
textPanel = new JPanel();
textPanel.setLayout(new GridLayout(2, 1));
add(textPanel, BorderLayout.CENTER);
userName = new JTextField(30);
userPassword = new JTextField(30);
textPanel.add(userName);
textPanel.add(userPassword);
loginButton = new JButton("Login");
FrameListener loginListener = new FrameListener();
loginButton.addActionListener(loginListener);
add(loginButton, BorderLayout.SOUTH);
}
private class FrameListener implements ActionListener
{
@Override
public void actionPerformed(ActionEvent e)
{
String actionCommand = e.getActionCommand();
if(actionCommand.equals("Login"))
{
if(!(userName.getText().equals("")) && !(userPassword.getText().equals("")))
{
userNameString = userName.getText();
userPasswordString = userPassword.getText();
//Access your database of credentials here
SwingUtilities.invokeLater(new Runnable()
{
@Override
public void run()
{
OtherClass mainProgram = new OtherClass(Login.this);
mainProgram.setVisible(true);
}
});
dispose();
}
}
}
}
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
@Override
public void run()
{
Login loginFrame = new Login();
loginFrame.setVisible(true);
}
});
}
public String getUserName()
{
return userNameString;
}
public String getUserPassword()
{
return userPasswordString;
}
}
获取此信息的类需要具有:
import javax.swing.JFrame;
public class OtherClass extends JFrame
{
final Login loginClass;
private String userName;
private String userPassword;
public OtherClass(Login e)
{
loginClass = e;
userName = loginClass.getUserName();
userPassword = loginClass.getUserPassword();
System.out.println("Your User Name is: " + userName);
System.out.println("Your Password is: " + userPassword);
}
}
关于java - 如何链接 2 个类以共享文本字段及其属性,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/14347230/