How to change a file reader to a directory scanner?

Question

Answer

System.out.print("Enter the name of the directory:");
File a= new File((new BufferedReader(new 
InputStreamReader(System.in))) .readLine()); 
File[] b=a.listFiles(); 
for(int i=1;i < b.length;i++){
fn=b[i].getPath(); }

Problem

System.out.print("Enter the name of file: ");
fn = (new BufferedReader(new InputStreamReader(System.in)))
        .readLine();

I have tried

File[] file Array=new File(System.in).listFiles();
for(File f: fileArray) // loop through all files { 
  if(f.getName().endsWith(".fasta")){
     fn = (new BufferedReader(new InputStreamReader(fileArray)).readLine()); // to read the files }}`

but receive an error of The constructor File(InputStream) is undefined

I want to change fn to a directory. How do I iterate through the directory keeping the Buffered Reader and InputStreamReader?

Can you give example of what you are trying to achieve (and to avoid [XY problem](http://meta.stackexchange.com/questions/66377/what-is-the-xy-problem) why do you think you need to do this this way)? — Pshemo, Jun 10 '15 at 15:19
In `fn` you got `String` with user input. If it is correct file name or correct path you can simple use `new File(fn)`. This file object can be used to work with file system. PS you cannot use current `BufferedReader` and `InputStreamReader` - they haven't their own object variable and they don't involved in work with file system. — Pavel Uvarov, Jun 10 '15 at 15:26
I read in fn as the location of the file. I use this to read through a fasta sequence. I have tried `System.out.print("Enter the name of the file:"); File[] fileArray=new File(System.in).listFiles(); fn = (new BufferedReader(new InputStreamReader(f)) .readLine();` but receive an error of _The constructor File(InputStream) is undefined_ @Pshemo — Pietro Sette, Jun 10 '15 at 15:29
Don't add new informations in comments, especially if it is code fragment which can't be properly formatted there. Instead use [edit] option and add it to question. — Pshemo, Jun 10 '15 at 15:34
@PavelUvarov Is it possible to have a directory loop through all of the files, each time declaring fn as the filename with BufferedReader and InputStreamReader? — Pietro Sette, Jun 10 '15 at 15:35
Again - your `fn` is String object. You can try create `File` object by `new File(fn)` and work with it. So you need: 1. assign user input to `String` (your actual sources in question), 2. use this `String` object to create `File` object and work with its API. — Pavel Uvarov, Jun 10 '15 at 15:43
@PavelUvarov AH, I see. Thank you Pavel! Sorry for my limited grasp of java! — Pietro Sette, Jun 10 '15 at 15:54

score 0 · Accepted Answer · answered Jun 10 '15 at 16:17

I can see you want to read the content into another file...

the following classes are used for writing/reading data to files. FileOutputStream,FileInputStream;

as you can see, FileOuputStream is used in writing data to a file and FileInputStream is used in reading data from a file.

the data can be text,image,video, etc.

you can a create an instance of FileInputStream like this

//replace the string with actual file name    
File fileToReadFrom = new File("path/to/file");
FileInputStream = new FileInputStream(fileToReadFrom);

and similarly you create an instance of FileOutputStream like this:

//replace the string with actual file name    
File fileToWriteTo= new File("path/to/file");
FileInputStream = new FileInputStream(fileToWriteTo);

with instances of these classes you can read and write from/to any file. you can read more about them here

How to change a file reader to a directory scanner?

1 Answers1