Java - how to get all the file names in a folder

Question

I'm not a really good Java programmer and I need to know how I can print out all the files in a single folder. See the code below:

for(int i=0;i<folder.number_of_files;i++){
System.out.println(filename[i]);
}

Thanks for your time

Answer 1

Easiest way would be to use File#listFiles . And if you're using Java 7, see this for changes to the file I/O library. For instance,

File folder = ...;
for(File f : folder.listFiles())
{
    System.out.println(f.getName());
}

Note that this will not grab the contents of any sub-folders within the folder directory.

Answer 2

 File file = new File("C:\\");  
 File[] files = file.listFiles();  
 for (File f:files)  
 {  
     System.out.println(f.getAbsolutePath());  
 }  

listFiles() has more options. see the documentation here

Answer 3

If you also want to check subfolders below example runs a recursive and check all files under Desktop and its subfolders and writes into a list.

private static String lvl = "";
    static BufferedWriter bw;
    private static File source = new File("C:\\Users\\"+System.getProperty("user.name")+"\\Desktop\\New folder\\myTest.txt");

    public static void main(String[] args) throws IOException {




        bw = new BufferedWriter(new FileWriter(source));

        checkFiles(new File("C:\\Users\\"+System.getProperty("user.name")+"\\Desktop"), 0);


        bw.flush();
        bw.close();
        lvl = null;

    }
    static void checkFiles(File file, int level) throws IOException{

        if(!file.exists()){

            return;
        }

        for(String s:file.list()){

            if(new File(file.getPath() + "\\" +  s).isDirectory()){

                bw.newLine();
                bw.write(lvl + "Directory: " + s);

                lvl += " ";

                checkFiles(new File(file.getPath() + "\\" +  s), level+1);

            }else{

                bw.newLine();
                bw.write(lvl + "File: " + s);

            }
        }
    }
}