Código
import java.io.BufferedReader; import java.io.FileInputStream; import java.io.IOException; import java.io.InputStreamReader; import java.util.ArrayList; import java.util.Iterator; import java.util.SortedSet; import java.util.TreeSet; import javax.swing.JOptionPane; public class LeeFichero { try { String linea; int c =0; ArrayList<Character> arrayList = new ArrayList<Character>(); while((linea=leer.readLine())!=null) { char chars[]=linea.toCharArray(); for(int index=0;index<chars.length;index++){ arrayList.add(chars[index]); c++; } } } isr.close(); leer.close(); SortedSet<Character> characters = new TreeSet<Character>(); Iterator<Character> interator = arrayList.iterator(); while(interator.hasNext()){ characters.add(interator.next()); } if(characters.size()<26){ }else } e.printStackTrace(); } } }
PD: mi logica puede que no la entiendas,es la forma mas simple que se me ocurrio
Saluidos.