如何列出目录及其所有子目录中的所有文件

Question

I've made a program that lists all file names in a desired directory of your extension choice. Now I want to and I don't know how to change it to list all files within sub-directories too. Do you have any ideas? Here's my code. Thanks!

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

public class Program {

    public static void main(String str[]){
        try{
            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
            System.out.println("1.Enter directory name:");
            String adress = br.readLine();
            System.out.println("2.Enter file extension:");
            String exten = br.readLine();

            File directory = new File(adress);

            File[] f = directory.listFiles();     

            List<String> files = new ArrayList<String>();
            List<String> valid = new ArrayList<String>();
            List<String> names = new ArrayList<String>();

            for(int i=0; i < f.length; i++){
                if(f[i].isFile()){
                    files.add(f[i].getName());
                }
            }

            for(int i=0; i < files.size(); i++){
                if (files.get(i).endsWith(exten)){
                    valid.add(files.get(i));
                }
            }

            for(int i=0; i < valid.size(); i++){
                int pos = valid.get(i).lastIndexOf(".");
                    names.add(valid.get(i).substring(0, pos));
                    System.out.println(names.get(i));
            }
       }
        catch(Exception e){
            e.printStackTrace();
        }
    }
}

Answer 1

If you can use Java 7 or 8 you could use the FileVisitor , but in Java 7 it means writing more then one line of code. If not and you want to keep it simple, Apache Commons FileUtils may be your friend.

Collection<File> files = FileUtils.listFiles(path, new String[]{"xlxs"}, true);

Answer 2

I made this awhile back to find all of *.xls or *.xlsx in a directory.

Hope this will help you with your question.

public static List<String> fileSearch(String d){
        List<String> filesFound = new ArrayList<String>();
        File dir = new File(d);
        try{
        for(File file: dir.listFiles()){
            if(file.isFile() && (file.getName().toLowerCase().endsWith(".xlsx") || file.getName().toLowerCase().endsWith(".xls"))){

                long filesize = file.length();
                long fileSize = filesize / 1024;

                filesFound.add(d + "\\" + file.getName());
                System.out.println("Added: " + d + "\\" + file.getName()  + "     " + fileSize + " KB" );
            }else if(file.isDirectory() && !file.isHidden()){
                System.out.println("Found Directory: " + file.getName());
                filesFound.addAll(fileSearch(d + "\\" + file.getName()));
            }else if(isRoot(file)){
                        //DO NOTHING
            }
        }

        }catch(NullPointerException ex){
            ex.printStackTrace();
        }finally{
            return filesFound;
        }
    }

private static boolean isRoot(File file){
        File[] roots = File.listRoots();

        for (File root : roots) {
            if (file.equals(root)) {
            return true;
            }
        }

        return false;
    }

What this does, it will search every file for a match and if it matches then it will add it to the array "filesFound" from there you can get all the paths of matched files. BUT for you, you would take out the .xlsx and .xls part and add in your ext.

fileSearch(String d, String ext)

and change the if then to:

if(file.isFile() && file.getName().toLowerCase().endsWith(ext))

ALSO i have it outputting when ever it finds a match with the file size next to it. The file size is just a visual aid and does not get included in the array.