На IntelliJ Idea работает даже с поддиректориями
package com.javarush.task.task31.task3101;
/*
Проход по дереву файлов
*/
import java.io.*;
import java.util.ArrayList;
import java.util.Collections;
public class Solution {
public static void main(String[] args) throws IOException {
ArrayList<File> list = new ArrayList<File>();
String path = args[0];
String resultFileAbsolutePath = args[1];
File folder = new File(path);
File file = new File(resultFileAbsolutePath);
String dist = path + "/" + "allFilesContent.txt";
File file2 = new File(dist);
FileUtils fu = new FileUtils();
if (fu.isExist(file)) {
fu.renameFile(file, file2);
}
for (File files : folder.listFiles()) {
if ((files.length() <= 50) && (files.isFile())) {
list.add(files);
} else if (files.isDirectory()) {
File[] docs = files.listFiles();
for (File d : docs) {
if (d.getName().contains(".txt")){
list.add(d);
}
}
}
}
Collections.sort(list);
BufferedReader r;
BufferedWriter w = new BufferedWriter(new FileWriter(file2));
String pathNew="";
for (int i = 1; i < list.size(); i++) {
r = new BufferedReader(new FileReader(list.get(i).getAbsolutePath()));
String s = r.readLine();
w.write(s+"\n");
w.flush();
}
w.close();
}
}