W3Schools Tryit Editor

import java.io.File;
import java.io.FileNotFoundException;
import java.util.Scanner;
public class ReadFile {
 public static void main(String[] args) {
 File myObj = new File("filename.txt");
 // try-with-resources: Scanner will be closed automatically
 try (Scanner myReader = new Scanner(myObj)) {
 while (myReader.hasNextLine()) {
 String data = myReader.nextLine();
 System.out.println(data);
 }
 } catch (FileNotFoundException e) {
 System.out.println("An error occurred.");
 e.printStackTrace();
 }
 }
}