小编ddj*_*jh5的帖子

我目前正在制作一个应用程序，用户可以在其中添加多个帐户。登录信息存储在文本文件中。我需要一种方法让用户添加新帐户，而 BufferedWriter 不会覆盖其他帐户的信息。有什么建议么？

package mainFiles.fileManagers;

import java.io.*; 


public class NewTXT {


 public static void nFile( String a , String b ) throws IOException {

     File f = new File("mainFiles\\storage\\accountinfo.txt");
     FileWriter writer = new  FileWriter("mainFiles\\storage\\accountinfo.txt"); 
     BufferedWriter bWriter = new BufferedWriter(writer); 



     f.createNewFile(); 
     f.canWrite(); 
     bWriter.newLine(); 
     bWriter.write(a + "?" + b );
     bWriter.newLine();
     bWriter.close(); 

 }

}

我正在尝试将文件写入Java中的特定目录.我已经在Stack Overflow论坛中查看了许多与此相关的问题.然而,我尝试的每种方法最终都会出现此错误:

java.io.IOException: No such file or directory
at java.io.UnixFileSystem.createFileExclusively(Native Method)
at java.io.File.createNewFile(File.java:1012)
at mainFiles.fileManagers.NewCSV.nJSON(NewCSV.java:40)
at mainFiles.appWindows.UserDashboard$1.run(UserDashboard.java:30)
at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:756)
at java.awt.EventQueue.access$500(EventQueue.java:97)
at java.awt.EventQueue$3.run(EventQueue.java:709)
at java.awt.EventQueue$3.run(EventQueue.java:703)
at java.security.AccessController.doPrivileged(Native Method)
at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:80)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:726)
at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:201)
at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

码:

public static void nJSON(String username) { 

    File file = new File("src/jsonFiles/" +  username + ".json");

    try {
        if (file.exists() && file.isDirectory()) {
            System.out.println(username + ".json exist.");
        } else {
            json.put("Username", username); 
            json.put("Password", mainFiles.windowsSrc.UserInfo.password); …