所以我开始为我的PAT Grade 12任务创建这个项目，然后我遇到了一个减速带...
我在netbeans中有一个使用jFrame的登录屏幕。
我的问题是，我正在使用2个文本文件来存储数据：1个用于用户名，1个用于密码。它们使用扫描仪读取，并以＃分隔。
关键是，我使用while循环验证了用户名，但是我无法验证与另一个文本文件中的该用户名相对应的密码。
因此，您可以想象2个文本文件：
用户名
密码
单击“登录”按钮时，它将使用while循环来检查用户名是否已存在。如果是这样，请继续输入密码，否则“用户名不存在”。当在另一个文本文件中的相同位置匹配密码时，就会出现问题。
如果有人可以帮助我，那将使我度过一周并保存我的项目。
请理解，Netbeans仅允许您编辑某些代码区域。我尽我所能保持代码的清洁和易于理解。
非常感谢，
吸血鬼
package Battlefield4;
import javax.swing.*;
import java.util.*;
import java.io.*;
import java.util.logging.Level;
import java.util.logging.Logger;
public class Login extends javax.swing.JFrame
{
String Username;
String Password;
public Login()
{
initComponents();
}
//Can not edit from here on
private void initComponents() {
txtUsername = new javax.swing.JTextField();
txtPassword = new javax.swing.JTextField();
lblPassword = new javax.swing.JLabel();
lblUsername = new javax.swing.JLabel();
btnLogin = new javax.swing.JButton();
btnCreate = new javax.swing.JButton();
jLabel1 = new javax.swing.JLabel();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setSize(new java.awt.Dimension(854, 480));
getContentPane().setLayout(new org.netbeans.lib.awtextra.AbsoluteLayout());
getContentPane().add(txtUsername, new org.netbeans.lib.awtextra.AbsoluteConstraints(320, 150, 210, -1));
getContentPane().add(txtPassword, new org.netbeans.lib.awtextra.AbsoluteConstraints(320, 220, 210, -1));
lblPassword.setText("Password");
getContentPane().add(lblPassword, new org.netbeans.lib.awtextra.AbsoluteConstraints(320, 200, -1, -1));
lblUsername.setText("Username");
getContentPane().add(lblUsername, new org.netbeans.lib.awtextra.AbsoluteConstraints(320, 130, -1, -1));
btnLogin.setText("Login");
btnLogin.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btnLoginActionPerformed(evt);
}
});
getContentPane().add(btnLogin, new org.netbeans.lib.awtextra.AbsoluteConstraints(320, 290, -1, -1));
btnCreate.setText("Create");
btnCreate.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
btnCreateActionPerformed(evt);
}
});
getContentPane().add(btnCreate, new org.netbeans.lib.awtextra.AbsoluteConstraints(460, 290, -1, -1));
jLabel1.setIcon(new javax.swing.ImageIcon(getClass().getResource("/Battlefield4/Batfield/Background/Login (Small).jpg"))); // NOI18N
jLabel1.setText("jLabel1");
getContentPane().add(jLabel1, new org.netbeans.lib.awtextra.AbsoluteConstraints(0, 0, 860, 480));
pack();
}
//Can not edit before this
private void btnLoginActionPerformed(java.awt.event.ActionEvent evt) {
//This is from where Netbeans lets you edit your code.
try {
File user = new File("C:\\Users\\John1012\\Documents\\NetBeansProjects\\PATProject\\src\\Battlefield4\\Batfield\\Users\\Username.txt"); //To create a universal file for Input & Output
File pass = new File("C:\\Users\\John1012\\Documents\\NetBeansProjects\\PATProject\\src\\Battlefield4\\Batfield\\Users\\Password.txt"); //To create a universal file for Input & Output
user.getParentFile().mkdirs(); //To denote the parent file
pass.getParentFile().mkdirs(); //To denote the parent file
Scanner scUser = new Scanner(user).useDelimiter("#"); //To scan the Username file
Scanner scPass = new Scanner(pass).useDelimiter("#");
Username = txtUsername.getText(); //This gets the user input
Password = txtPassword.getText(); //This gets the user input
int pos = 0; //Indicates the position of the Username in the save file
while(scUser.hasNext())
{
pos = pos + 1;
if(scUser.equals(Username))
{ //This is where it fails
for (int i = 0; i <= 5; i++)
{
while(scPass.hasNext())
{
System.out.print(scPass);
}
}
if(scPass.equals(Password))
{
new Selection().setVisible(true);
this.dispose();
}
else
{
JOptionPane.showMessageDialog(null,"Incorrect Password!");
}
}//This is where it works from. The above code is sketchy
else
{
JOptionPane.showMessageDialog(null,"User Does Not Exist!");
}
scUser.close();
}
}
catch (FileNotFoundException ex)
{
Logger.getLogger(Login.class.getName()).log(Level.SEVERE, null, ex);
}
catch (IOException ex)
{
Logger.getLogger(Login.class.getName()).log(Level.SEVERE, null, ex);
}
}
private void btnCreateActionPerformed(java.awt.event.ActionEvent evt) {
//Again this is from where Netbeans lets you edit
try {
File user = new File("C:\\Users\\John1012\\Documents\\NetBeansProjects\\PATProject\\src\\Battlefield4\\Batfield\\Users\\Username.txt"); //To create a universal file for Input & Output
File pass = new File("C:\\Users\\John1012\\Documents\\NetBeansProjects\\PATProject\\src\\Battlefield4\\Batfield\\Users\\Password.txt"); //To create a universal file for Input & Output
user.getParentFile().mkdirs(); //To denote the parent file
pass.getParentFile().mkdirs(); //To denote the parent file
Scanner scUser = new Scanner(user); //To scan the Username file
Username = txtUsername.getText(); //This gets the user input
Password = txtPassword.getText(); //This gets the user input
if(scUser.nextLine().contains(Username)) //This reads the entire line and checks for an indexOf of those characters
{
JOptionPane.showMessageDialog(null,"User Already Exists!");
scUser.close(); //Close the Scanner
}
else
{
scUser.close(); //Close the Scanner
if("".equals(Password) || " ".equals(Password)) //Checks to see whether or not the user entered a password
{
JOptionPane.showMessageDialog(null,"Please Enter A Password!");
}
else
{
PrintWriter pwUser = new PrintWriter(new FileWriter(user,true)); //To Write to the Username file
PrintWriter pwPass = new PrintWriter(new FileWriter(pass,true)); //To Write to the Password file
pwUser.print(Username + "#");
pwPass.print(Password + "#");
pwUser.close();
pwPass.close();
new Selection().setVisible(true);
this.dispose();
}
}
scUser.close();
}
catch (FileNotFoundException ex)
{
Logger.getLogger(Login.class.getName()).log(Level.SEVERE, null, ex);
}
catch (IOException ex)
{
Logger.getLogger(Login.class.getName()).log(Level.SEVERE, null, ex);
}
}
//Can no longer edit here
public static void main(String args[]) {
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(Login.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Login.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Login.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Login.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Login().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton btnCreate;
private javax.swing.JButton btnLogin;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel lblPassword;
private javax.swing.JLabel lblUsername;
private javax.swing.JTextField txtPassword;
private javax.swing.JTextField txtUsername;
// End of variables declaration
}
最佳答案
在启动时映射所有用户，然后仅检查映射。使用split分隔用户名和密码。在调用onLoginCorrect（）之前检查输入是否为空
private static final Logger LOG = LogManager.getLogger();
private final Map<String, String> users = new ConcurrentHashMap<>();
public Login() {
super();
final InputStream resource = this.getClass().getResourceAsStream("/users.txt");
final Scanner scanner = new Scanner(resource);
while (scanner.hasNext()) {
final String input = scanner.nextLine();
final String[] userPw = StringUtils.split(input, ':');
this.users.put(userPw[0], userPw[1]);
}
scanner.close();
IOUtils.closeQuietly(resource);
}
public boolean isLoginCorrect(final String username,final String password) {
final boolean result;
if (StringUtils.equals(this.users.get(username), password)) {
result = true;
} else {
Login.LOG.warn("No such user");
result = false;
}
return result;
}