密码对话框程序

深碍√TFBOYSˉ_ 2022-12-06 15:47 151阅读 0赞

Here is example Java code showing how to make a password dialog box. This program uses a combination of the `JOptionPane` class and the `JPasswordField` class.

这是示例Java代码，显示了如何制作密码对话框。 该程序使用`JOptionPane`类和`JPasswordField`类的组合。

When this program is run a `JOptionPane` is shown containing a `JPasswordField`, a `JTextField`, an OK and Cancel button. The `JFrame` behind the `JOptionPane` uses a text area to provide feedback about the input the user has made and what buttons have been pressed.

运行该程序时，将显示一个`JOptionPane` ，其中包含`JPasswordField` ， `JTextField` ，“确定”和“取消”按钮。 `JOptionPane`后面的`JFrame`使用文本区域来提供有关用户进行的输入以及按下了哪些按钮的反馈。

The article relating to this code is How to Make a Password Dialog Box. Also, have a look at [JPasswordField Overview][] if you want more specific information about the `JPasswordField` class.

与该代码有关的文章是如何制作密码对话框。 另外，如果您想要有关`JPasswordField`类的更多特定信息，请查看[JPasswordField概述][JPasswordField Overview] 。

**Note:**For this [Java program][] to work it needs to be saved in a file called PasswordDialog.java

**注意：**为了使该[Java程序][Java program]正常工作，需要将其保存在名为PasswordDialog.java的文件中。

//Imports are listed in full to show what's being used
    //could just import javax.swing.* and java.awt.* etc..
    import javax.swing.JFrame;
    import javax.swing.JOptionPane;
    import javax.swing.JTextField;
    import javax.swing.JTextArea;
    import javax.swing.JPasswordField;
    import javax.swing.JPanel;
    import javax.swing.JLabel;
    import java.awt.GridLayout;
    import java.util.Arrays;
    import java.awt.EventQueue;
    public class PasswordDialog {
    //Note: Typically the main method will be in a
    //separate class. As this is a simple one class
    //example it's all in the one class.
    public static void main(String[] args) {
    //Use the event dispatch thread for Swing components
    EventQueue.invokeLater(new Runnable()
    {
    @Override
    public void run()
    {
    createGuiFrame();
    }
    });
    }
    //handles the creation of the JFrame and
    //all it's components
    private static void createGuiFrame()
    {
    JFrame guiFrame = new JFrame();
    //make sure the program exits when the frame closes
    guiFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    guiFrame.setTitle("Dialog Box Example");
    guiFrame.setSize(500,300);
    //This will center the JFrame in the middle of the screen
    guiFrame.setLocationRelativeTo(null);
    guiFrame.setVisible(true);
    //Using a JTextArea to diplay feedback
    //(i.e., the username and password entered
    JTextArea tracker = new JTextArea("Password Tracker:");
    guiFrame.add(tracker);
    //Using a JPanel as the message for the JOptionPane
    JPanel userPanel = new JPanel();
    userPanel.setLayout(new GridLayout(2,2));
    JLabel usernameLbl = new JLabel("Username:");
    JLabel passwordLbl = new JLabel("Password:");
    JTextField username = new JTextField();
    JPasswordField passwordFld = new JPasswordField();
    userPanel.add(usernameLbl);
    userPanel.add(username);
    userPanel.add(passwordLbl);
    userPanel.add(passwordFld);
    //As the JOptionPane accepts an object as the message
    //it allows us to use any component we like - in this case
    //a JPanel containing the dialog components we want
    int input = JOptionPane.showConfirmDialog(guiFrame, userPanel, "Enter your password:"
    ,JOptionPane.OK_CANCEL_OPTION, JOptionPane.PLAIN_MESSAGE);
    char[] correctPassword = {'a', 'P', 'a', 'S', 's', 'W', 'o', 'R', 'd'};
    if (input == 0) //OK Button = 0
    {
    tracker.append("\nUsername entered was: " + username.getText());
    //Retrieve password
    char[] enteredPassword = passwordFld.getPassword();
    tracker.append("\nPassword entered was: " + String.valueOf(enteredPassword));
    if (Arrays.equals(correctPassword, enteredPassword))
    {
    tracker.append("\nThe password entered is correct!");
    }
    else
    {
    tracker.append("\nCall security - it's an imposter!");
    }
    //Note: best practice is to zero out the array
    //that contains the password. (Bit silly here
    //as I'm printing the password to show how it's retrived
    //but keep it in mind when using JPasswordFields.)
    Arrays.fill(enteredPassword, '0');
    }
    else
    {
    //either the cancel button or the 'x'
    //has been pressed
    tracker.append("\nDialog cancelled..");
    }
    }
    }

> 翻译自: [https://www.thoughtco.com/password-dialog-box-program-2033978][https_www.thoughtco.com_password-dialog-box-program-2033978]

[JPasswordField Overview]: https://www.thoughtco.com/choicebox-overview-2033928
[Java program]: https://www.thoughtco.com/creating-your-first-java-program-2034124
[https_www.thoughtco.com_password-dialog-box-program-2033978]: https://www.thoughtco.com/password-dialog-box-program-2033978