Java 简单登录系统用户删除帐户文件系统异常

Question

您好，我正在尝试为作业实现一个简单的用户登录系统，这意味着能够删除您的帐户。启动时，用户登录系统程序在目录中查找文件夹，每个文件夹名称代表不同的用户，每个用户文件夹都包含一个"INFO.txt"文件，该文件显示其用户名和密码。出于某种原因，当我尝试删除用户目录中的文件时，我从 eclipse 控制台收到以下错误：

java.nio.file.FileSystemException: usersgeorgeINFO.txt: The process cannot access the file because it is being used by another process.
at sun.nio.fs.WindowsException.translateToIOException(Unknown Source)
at sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
at sun.nio.fs.WindowsException.rethrowAsIOException(Unknown Source)
at sun.nio.fs.WindowsFileSystemProvider.implDelete(Unknown Source)
at sun.nio.fs.AbstractFileSystemProvider.delete(Unknown Source)
at java.nio.file.Files.delete(Unknown Source)
at MessagingApp.deleteAccount(MessagingApp.java:414)
at MessagingApp.mainMenu(MessagingApp.java:333)
at MessagingApp.login(MessagingApp.java:237)
at MessagingApp.start(MessagingApp.java:180)
at MessagingApp.<init>(MessagingApp.java:30)
at Main.main(Main.java:5)
java.nio.file.DirectoryNotEmptyException: usersgeorge
at sun.nio.fs.WindowsFileSystemProvider.implDelete(Unknown Source)
at sun.nio.fs.AbstractFileSystemProvider.delete(Unknown Source)
at java.nio.file.Files.delete(Unknown Source)
at MessagingApp.deleteAccount(MessagingApp.java:424)
at MessagingApp.mainMenu(MessagingApp.java:333)
at MessagingApp.login(MessagingApp.java:237)
at MessagingApp.start(MessagingApp.java:180)
at MessagingApp.<init>(MessagingApp.java:30)
at Main.main(Main.java:5)

这是我的类，其中包含我的删除帐户方法和启动时调用的加载方法：

public class MessagingApp {
private Scanner scanner;
private ArrayList<User> userList; //All users currently registered
private User currentUser; //The user currently logged in
public MessagingApp() {
    scanner = new Scanner(System.in);
    userList = new ArrayList<User>();
    try {
        this.load();
    } catch (IOException e) {
        e.printStackTrace();
    }
    this.start();
}
/**
 * loads all user information currently stored 
 * @throws IOException 
 */
private void load() throws IOException {
    Path users = Paths.get("users");
    File usersDir = users.toFile();
    String[] entries = usersDir.list(); //Each string in this list represents a user folder
    if(entries!=null) {
        for(String s: entries) {
            Path thisUser = Paths.get("users/"+s);
            File thisUserDir = thisUser.toFile();
            String[] userFiles = thisUserDir.list();
            for(String file: userFiles) {
                if( file.equals("INFO.txt") ) {
                    try {
                        BufferedReader reader = new BufferedReader(new FileReader("users/"+s+"/INFO.txt"));
                        String info = reader.readLine();
                        String[] credentials = info.split(":");
                        userList.add(new User(credentials[0],credentials[1]));
                        credentials=null;
                        info = null;
                        reader=null;
                    } catch (FileNotFoundException e) {
                        e.printStackTrace();
                    }
                }
            }
        }
    }
}
private void deleteAccount() {
    String choice;
    System.out.println("Are you sure you want to delete your account?");
    while(true) {
        choice = scanner.nextLine();
        if((choice.equals("y"))||(choice.equals("n"))) {
            break;
        }
        System.err.println("Invalid selection");
    }
    if( choice.equals("n") ) {
        mainMenu();
    }
    if( choice.equals("y") ) {
        Path userPath = Paths.get("users/"+currentUser.getUsername());
        File userDir = userPath.toFile();
        String[] userFiles = userDir.list();
        if(userFiles!=null) {
            for(String s: userFiles) {
                Path userFilePath = Paths.get("users/"+currentUser.getUsername()+"/"+s);
                try {
                    Files.delete(userFilePath);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        try {
            Files.delete(userPath);
        } catch (IOException e) {
            e.printStackTrace();
        }
        userList.remove(currentUser);
        currentUser=null;
    }
}

如果有人有任何关于我出错的地方的指示，将不胜感激，谢谢

Answer 1

可能是

您在某个应用程序中打开了"users\george\INFO.txt"。例如，在记事本或 IDE 中。因此，它会锁定它，使其不被您的应用删除。

我给你的建议是单独尝试这个特定的功能。例如，我已经尝试了以下代码片段，它适用于我的环境。

import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

public class MessagingApp {
    public static void main(String args[]) {
        deleteAccount();
    }
    private static void deleteAccount() {
            Path userFilePath = Paths.get("Z:/users/test/INFO.txt");
            try {
                Files.delete(userFilePath);
            } catch (IOException e) {
                e.printStackTrace();
            }
    }
}

这基本上与您相同，但非常简化。请在文件系统上创建一个单独的类和一个测试文件并对其进行测试。如果它有效，您可以确定代码很可能是正常的，并且问题出在环境中。再说一次，我猜你在其他地方打开了它。希望对您有所帮助。