Файлы

Запись в файл

import java.io.File;

import java.io.PrintWriter;

import java.util.Scanner;

public class Main {

   public static void main(String[] args) {

       Scanner scanner = new Scanner(System.in);

       String s = scanner.nextLine();

       File file = new File("output.txt");

       try {

           PrintWriter printWriter = new PrintWriter(file);

           printWriter.write(s);

           printWriter.close();

       } catch (Exception e) {

           System.out.println("Ошибка!");

       }

   }

}

Чтение и запись

import java.io.File;

import java.io.FileNotFoundException;

import java.io.FileWriter;

import java.io.IOException;

import java.util.Scanner;

public class FileController {

   public static void save(String filename, String text){

       File file = new File(filename);

       try {

           FileWriter writer = new FileWriter(file);

           writer.write(text);

           writer.close();

       } catch (IOException e) {

           System.out.println("Ошибка");

       }

   }

   public static String load(String filename){

       File file = new File(filename);

       StringBuilder result = new StringBuilder();

       try {

           Scanner scanner = new Scanner(file);

           while (scanner.hasNextLine()){

               result.append(scanner.nextLine());

               result.append("\n");

           }

       } catch (FileNotFoundException e) {

           System.out.println("Ошибка");

       }

       return result.toString();

   }

}