[JAVA] 텍스트 파일 읽기, 쓰기

텍스트파일에 그냥 쓰기

   FileWriter writer = new FileWriter("ReadAndWrite.txt"); 
   writer.write("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n");
   writer.write("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n");
   writer.write("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n");
   writer.write("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n");
   writer.close();

텍스트파일에 버퍼를 사용하여 쓰기

   FileWriter fileWriter = new FileWriter("ReadAndWrite.txt");
   BufferedWriter writer = new BufferedWriter(fileWriter);
   writer.write("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n");
   writer.write("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n");
   writer.write("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n");
   writer.write("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\n");
   writer.close(); 

텍스트파일을 버퍼를 이용하여 읽기

   FileReader fileReader = new FileReader("ReadAndWrite.txt");
   BufferedReader reader = new BufferedReader(fileReader);
   
   String line = null;

   while((line = reader.readLine()) != null ) {
    System.out.println(line);
   }

   reader.close();

햇갈리지 말자!

객체를 저장할때는
objectOutputStream.writeObject(someObject);

String을 저장할때는
fileWriter.write("하고싶은말");