PrintStream 没有创建文件？

Question

我在第 58 行收到一个错误，提示找不到文件，但 PrintStream 不应该创建该文件吗？（注意：根本没有创建文件。）

谢谢！

WhyDoINeedToAddMoreDetailIAlreadySaidWhatINeedToSay

import java.io.*;
import java.util.*;
import java.text.*;

public class DownloadsFolderCleanup {
   public static String directory = "C:\Users\User\Downloads";
   
   public static void main(String[] args) throws FileNotFoundException {
      File[] files = (new File(directory)).listFiles();
      if (files.length - 1 == 0) {
         System.out.println("Downloads folder is already empty!");
      }
      else {
         ArrayList<File> markedFiles = new ArrayList<File>();
         int numInstallers = 0, numIncompleteDownloads = 0;
         for (File file : files) {
            String fileName = file.getName();
            if (fileName.substring(fileName.length() - 4,fileName.length()).equals(".exe")) {
               if (fileName.toLowerCase().contains("install") || fileName.toLowerCase().contains("setup")) {
                  markedFiles.add(file);
                  numInstallers++;
                  System.out.println('"' + fileName + '"' + " marked for deletion.   Reason: Installer");
               }
            }
            if (fileName.length() > 22) {
               if (fileName.substring(0,11).equals("Unconfirmed") && fileName.substring(fileName.length() - 11, fileName.length()).equals(".crdownload")) {
                  markedFiles.add(file);
                  numIncompleteDownloads++;
                  System.out.println('"' + fileName + '"' + " marked for deletion.   Reason: Incomplete download");
               }
            }
         }
         System.out.println("- - - - - - - - - - - - - - - - - - - -");
         System.out.println("Total # of files scanned: " + (files.length - 1));
         System.out.println("Total # of junk files found: " + markedFiles.size());
         System.out.println("Installers found: " + numInstallers);
         System.out.println("Incomplete download files found: " + numIncompleteDownloads);
         if (markedFiles.size() == 0) {
            System.out.println("No junk files were found!");
         }
         else {
            System.out.print("Please confirm removal of all identified files. CANNOT BE UNDONE!   Y/N: ");
            Scanner input = new Scanner(System.in);
            if (input.nextLine().equalsIgnoreCase("Y")) {
               System.out.println("All marked files will be permanently deleted in 5 seconds.");
               for (int c = 4; c > 0; c--) {
                  sleep1second();
                  System.out.println(c + "...");
               }
               sleep1second();
               DateFormat dateFormat = new SimpleDateFormat("MM/dd/yyyy HH:mm");
               Date date = new Date();
               PrintStream log = new PrintStream(new File(dateFormat.format(date) + " Download Folder Cleanup Log.txt"));
               for (File file : markedFiles) {
                  System.out.println('"' + file.getName() + '"' + " deleted.");
                  file.delete();
                  log.println(file.getName());
               } 
               log.close();
            }
         }
      }
      System.out.println();
      System.out.println("Cleanup process complete!");
   }
   
   public static void sleep1second() {
      try {
          Thread.sleep(1000);
      }
      catch(InterruptedException ex) {
          Thread.currentThread().interrupt();
      }
   }
}

Answer 1

我猜你的 DateFormat "MM/dd/yyyy HH:mm" 包含“/”（斜杠），所以该路径无效，因为你正在制作在包含 dateFormat.format(date) 的路径中创建文件，无法创建文件。

在Windows中以下是禁止使用的字符：

* . " / \ [ ] : ; | = ,

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