while (true) { try { id = reader.readLine(); name = reader.readLine(); if (id.isEmpty() || name.isEmpty()) { break; } else { map.put(Integer.parseInt(id), name); } } catch (NullPointerException e) { break; } } for(Map.Entry<Integer, String > pair: map.entrySet()) System.out.println(pair.getKey() +" "+ pair.getValue());