Java 如何链接两个类以共享textfield及其属性
我试图在Java Netbeans IDE中为我的桌面应用程序运行数据代码修改，但问题是在有人可以修改数据之前，我希望通过在另一个JFrame表单中提供用户名和密码来确保该人获得授权。如果验证了用户名和密码，则只有修改任务才会成功；否则，用户将获得身份验证失败的错误。我试图在我的主窗体中编写代码，但是当我想在身份验证窗体的按钮单击事件中编写代码时，是否可能？我试过了，但它说你需要在这个类中声明该类的变量。请提供任何帮助 这是一个登录表单，我想用它来验证用户是否可以修改数据一旦用户被验证，我想允许他运行修改部分Java 如何链接两个类以共享textfield及其属性,java,swing,Java,Swing,我试图在Java Netbeans IDE中为我的桌面应用程序运行数据代码修改，但问题是在有人可以修改数据之前，我希望通过在另一个JFrame表单中提供用户名和密码来确保该人获得授权。如果验证了用户名和密码，则只有修改任务才会成功；否则，用户将获得身份验证失败的错误。我试图在我的主窗体中编写代码，但是当我想在身份验证窗体的按钮单击事件中编写代码时，是否可能？我试过了，但它说你需要在这个类中声明该类的变量。请提供任何帮助 这是一个登录表单，我想用它来验证用户是否可以修改数据一旦用户被验证，我想允许
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();
}
}
}
但主要的问题是修改部分来自另一种形式。这里有一个SSCCE，您可以测试一下，看看这是否是您希望能够做到的。我首先创建登录JFrame，要求用户输入他们的凭据。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，它将在OtherClass中用于检索存储在字符串中的JTextField信息。如果不传递整个登录类，即使使用getText（）以字符串形式存储JTextField内容，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;
}
}
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);
}
}
这里有一个SSCCE，你可以测试一下，看看这是否是你想要的。我首先创建登录JFrame，要求用户输入他们的凭据。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，它将在OtherClass中用于检索存储在字符串中的JTextField信息。如果不传递整个登录类，即使使用getText（）以字符串形式存储JTextField内容，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;
}
}
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);
}
}
如果您只有几个JTextFields要传递（就像您的登录案例一样），那么您也可以将每个值作为字符串传递给新的JFrame类的构造函数。这使得您不必使用访问器方法。如果有很多字段要传递，那么它也会使构造函数的参数变得非常混乱
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(userNameString, userPasswordString); //Here we pass the String values instead of the whole class
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);
}
});
}
//Note we no longer need accessor methods
}
import javax.swing.JFrame;
public class OtherClass extends JFrame
{
private String userName;
private String userPassword;
public OtherClass(String n, String p)
{
userName = n;
userPassword = p;
System.out.println("Your User Name is: " + userName);
System.out.println("Your Password is: " + userPassword);
}
}
请记住，传递经过if-else控件结构的字符串值比传递使用userName.getText（）获得的字符串值更好；检查仍将进行，但我认为传递检查的字符串是一个更好的主意。如果您只有几个JTextFields要传递（如登录情况），您也可以将每个值作为字符串传递给新的JFrame类的构造函数。这使得您不必使用访问器方法。如果有很多字段要传递，那么它也会使构造函数的参数变得非常混乱
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(userNameString, userPasswordString); //Here we pass the String values instead of the whole class
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);
}
});
}
//Note we no longer need accessor methods
}
import javax.swing.JFrame;
public class OtherClass extends JFrame
{
private String userName;
private String userPassword;
public OtherClass(String n, String p)
{
userName = n;
userPassword = p;
System.out.println("Your User Name is: " + userName);
System.out.println("Your Password is: " + userPassword);
}
}
请记住，传递经过if-else控件结构的字符串值比传递使用userName.getText（）获得的字符串值更好；检查仍将进行，但我认为最好是传递已检查的字符串。对于给您带来的不便，Andrew先生深表歉意。从现在起，我将确保以正确的方式进行检查。您可以创建该类的实例并访问该字段。检查它们的访问修饰符是否对其他类可用。如果该字段是静态的，则只需通过
ClassName.variableNameClassName.variableName