how to change the file path based on the OS

Question

i have a class which reads the list available in particular location,

the following is my code,

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

public class ExceptionInFileHandling {

   @SuppressWarnings({ "rawtypes", "unchecked" })
   public static void GetDirectory(String a_Path, List a_files, List a_folders) throws IOException {
       try {
           File l_Directory = new File(a_Path);
           File[] l_files = l_Directory.listFiles();

           for (int c = 0; c < l_files.length; c++) {
               if (l_files[c].isDirectory()) {
                   a_folders.add(l_files[c].getName());
               } else {
                   a_files.add(l_files[c].getName());
               }
           }
       } catch (Exception ex){
           ex.printStackTrace();
       }

   }
   @SuppressWarnings("rawtypes")
   public static void main(String args[]) throws IOException {

       String filesLocation = "asdfasdf/sdfsdf/";
       List l_Files = new ArrayList(), l_Folders = new ArrayList();
       GetDirectory(filesLocation, l_Files, l_Folders);

       System.out.println("Files");
       System.out.println("---------------------------");
       for (Object file : l_Files) {
           System.out.println(file);
       }
       System.out.println("Done");

   }
}

in this the file path can be passed as argument and that should be taken up based on the OS,

filePath.replaceAll("\\\\|/", "\\" + System.getProperty("file.separator"))

is this correct?

Answer 1

There are better ways to use file paths...

// Don't do this
filePath.replaceAll("\\\\|/", "\\" + System.getProperty("file.separator"))

Use java.nio.file.path:

import java.nio.file.*;

---

Path path = Paths.get(somePathString);
// Here is your system independent path
path.toAbsolutePath();
// Or this works too
Paths.get(somePathString).toAbsolutePath();

Use File.seperator:

// You can also input a String that has a proper file seperator like so
String filePath = "SomeDirectory" + File.separator;
// Then call your directory method
try{
    ExceptionInFileHandling.GetDirectory(filePath, ..., ...);
} catch (Exception e){}

---

So a simple change to your method will now work cross platform:

@SuppressWarnings({ "rawtypes", "unchecked" })
   public static void GetDirectory(String a_Path, List a_files, List a_folders) throws IOException {
       try {
           // File object is instead constructed 
           // with a URI by using Path.toUri()
           // Change is done here
           File l_Directory = new File(Paths.get(a_Path).toUri());

           File[] l_files = l_Directory.listFiles();
           for (int c = 0; c < l_files.length; c++) {
               if (l_files[c].isDirectory()) {
                   a_folders.add(l_files[c].getName());
               } else {
                   a_files.add(l_files[c].getName());
               }
           }
       } catch (Exception ex){
           ex.printStackTrace();
       }

   }

Answer 2

You can use forward slashes as directory separators on Windows as well when calling File constructor.