I/O

• 표준 입력

  String input = "";
  
  try {
      BufferedReader br = new BufferedReader( new InputStreamReader(System.in) );
      input = br.readLine();
      br.close();
  } catch (IOException e) {
      e.printStackTrace();
  } 
  

• Text에서 읽기

  try {
      Scanner sc;
      sc = new Scanner( new FileInputStream(fileName));
      while (sc.hasNext()) {
          // read contents by using sc.next();
      }
      sc.close();
  } catch (FileNotFoundException e) {
      e.printStackTrace();
  }
  

• Text 파일에 쓰기

  try {
      BufferedWriter writer;
      writer = new BufferedWriter ( new FileWriter(fileName) );
      writer.write("여기에 내용");
      writer.close();
  } catch (IOException e) {
      e.printStackTrace();
  }
  

• 직렬화된 객체를 파일에 쓰기

  FileOutputStream fos = new FileOutputStream("book.data"); // File 처리를 용이하게 하는 OutputStream
  BufferedOutputStream bos = new BufferedOutputStream(fos); // 속도향상
  ObjectOutputStream oos = new ObjectOutputStream(bos); // 객체전송
  oos.writeObject(b); // b : 직렬화된 객체
  oos.close();