Java says FileNotFoundException but file exists

Question

I have an assignment for my CS class where it says to read a file with several test scores and asks me to sum and average them  While summing and averaging is easy  I am having problems with the file reading  The instructor said to use this syntax Scanner scores   new Scanner new File  quot scores dat quot      However  this throws a FileNotFoundException  but I have checked over and over again to see if the file exists in the current folder  and after that  I figured that it had to do something with the permissions  I changed the permissions for read and write for everyone  but it still did not work and it still keeps throwing the error  Does anyone have any idea why this may be occurring  EDIT  It was actually pointing to a directory up  however  I have fixed that problem  Now file exists   returns true  but when I try to put it in the Scanner  it throws the FileNotFoundException Here is all my code import java util Scanner  import java io    public class readInt          public static void main String args                     File file   new File  quot lines txt quot                    System out println file exists                     Scanner scan   new Scanner file

User · Answer

Reading and writing from and to a file can be blocked by your OS depending on the file's permission attributes.

If you are trying to read from the file, then I recommend using File's setReadable method to set it to true, or, this code for instance:

String arbitrary_path = "C:/Users/Username/Blah.txt";
byte[] data_of_file;
File f = new File(arbitrary_path);
f.setReadable(true);
data_of_file = Files.readAllBytes(f);
f.setReadable(false); // do this if you want to prevent un-knowledgeable 
                      //programmers from accessing your file.

If you are trying to write to the file, then I recommend using File's setWritable method to set it to true, or, this code for instance:

String arbitrary_path = "C:/Users/Username/Blah.txt";
byte[] data_of_file = { (byte) 0x00, (byte) 0xFF, (byte) 0xEE };
File f = new File(arbitrary_path);
f.setWritable(true);
Files.write(f, byte_array);
f.setWritable(false); // do this if you want to prevent un-knowledgeable 
                      //programmers from changing your file (for security.)

User · Answer

There are a number situation where a FileNotFoundException may be thrown at runtime    The named file does not exist   This could be for a number of reasons including    The pathname is simply wrong The pathname looks correct but is actually wrong because it contains non-printing characters  or homoglyphs  that you did not notice The pathname is relative  and it doesn t resolve correctly relative to  the actual current directory of the running application   This typically happens because the application s current directory is not what you are expecting or assuming  The path to the file is is broken  e g  a directory name of the path is incorrect  a symbolic link on the path is broken  or there is a permission problem with one of the path components   The named file is actually a directory  The named file cannot be opened for reading for some reason    The good news that  the problem will inevitably be one of the above   It is just a matter of working out which   Here are some things that you can try    Calling file exists   will tell you if any file system object exists with the given name   pathname  Calling file isDirectory   will test if it is a directory  Calling file canRead   will test if it is a readable file  This line will tell you what the current directory is   System out println new File      getAbsolutePath      This line will print out the pathname in a way that makes it easier to spot things like unexpected leading or trainiong whitespace   System out println  The path is      path           Look for unexpected spaces  line breaks  etc in the output      It turns out that your example code has a compilation error   I ran your code without taking care of the complaint from Netbeans  only to get the following exception message      Exception in thread  main  java lang RuntimeException  Uncompilable   source code - unreported exception java io FileNotFoundException  must   be caught or declared to be thrown   If you change your code to the following  it will fix that problem   public static void main String   args  throws FileNotFoundException           File file   new File  scores dat        System out println file exists         Scanner scan   new Scanner file       Explanation  the Scanner File  constructor is declared as throwing the FileNotFoundException exception    It happens the scanner it cannot open the file    Now FileNotFoundException is a checked exception   That means that a method in which the exception may be thrown must either catch the exception or declare it in the throws clause   The above fix takes the latter approach

User · Answer

Use single  forward slash and always type the path manually  For example                                                           FileInputStream fi  new FileInputStream  D  excelfiles myxcel xlsx

User · Answer

An easy fix  which worked for me  is moving my files out of src and into the main folder of the project  It s not the best solution  but depending on the magnitude of the project and your time  it might be just perfect

User · Answer

Obviously there are a number of possible causes and the previous answers document them well  but here s how I solved this for in one particular case   A student of mine had this problem and I nearly tore my hair out trying to figure it out  It turned out that the file didn t exist  even though it looked like it did  The problem was that Windows 7 was configured to  Hide file extensions for known file types   This means that if file appears to have the name  data txt  its actual filename is  data txt txt    Hope this helps others save themselves some hair

User · Answer

I recently found interesting case that produces FileNotFoundExeption when file is obviously exists on the disk   In my program I read file path from another text file and create File object      String path was read from file System out println path     file with exactly same visible path exists on disk File file   new File path    System out println file exists        false System out println file canRead        false FileInputStream fis   new FileInputStream file       FileNotFoundExeption    The cause of the problem was that the path contained invisible  r n characters at the end   The fix in my case was    File file   new File path trim        To generalize a bit  the invisible   non-printing characters could have include space or tab characters  and possibly others  and they could have appeared at the beginning of the path  at the end  or embedded in the path   Trim will work in some cases but not all   There are a couple of things that you can help to spot this kind of problem    Output the pathname with quote characters around it  e g     System out println  Check me       path           and carefully check the output for spaces and line breaks where they shouldn t be  Use a Java debugger to carefully examine the pathname string  character by character  looking for characters that shouldn t be there    Also check for homoglyph characters

User · Answer

You d obviously figure it out after a while but just posting this so that it might help someone  This could also happen when your file path contains any whitespace appended or prepended to it

User · Answer

Apart from all the other answers mentioned here  you can do one thing which worked for me   If you are reading the path through Scanner or through command line args  instead of copy pasting the path directly from Windows Explorer just manually type in the path   It worked for me  hope it helps someone

User · Answer

The code itself is working correctly  The problem is  that the program working path is pointing to other place than you think   Use this line and see where the path is   System out println new File      getAbsoluteFile

User · Answer

I had this same error and solved it simply by adding the src directory that is found in Java project structure   String path   System getProperty  user dir        src  package name  file name   File file   new File path   Scanner scanner   new Scanner file     Notice that System getProperty  user dir   and new File      getAbsolutePath   return your project root directory path  so you have to add the path to your subdirectories and packages

[java] Java says FileNotFoundException but file exists

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