은성이의 프로그램X파일

* byte계열
  DataInputStream   -|
                     |-Primitive Data를 입출력하는 기능제공.
  DataOutputStream  -|

int i = 1456729;

FileOutputStream fo;
fo.write(i);

* project : day27
  package : file.io.filter
  class : DataStreamTest

package file.io.filter;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

public class DataStreamTest {
 private static String fileName = "d:\\prim.dat";
 public static void writeData(){
  DataOutputStream dos = null;
  try {
   dos = new DataOutputStream(new FileOutputStream(fileName));
   dos.writeInt(301201001);
   dos.writeBoolean(false);
   dos.writeLong(200100101010100L);
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }finally{
   if(dos!=null){
     try {
     dos.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  }
 }
 public static void readData(){
  DataInputStream dis = DataInputStream();
  try {
   dis = new DataInputStream(new FileInputStream(fileName));
   int i = dis.readInt();
   boolean b = dis.readBoolean();
   long l = dis.readLong();
   System.out.println(i);
   System.out.println(b);
   System.out.println(l);
//   System.out.println(i+b+l);
   System.out.println(i+"\n"+b+"\n"+l);
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }finally{
   if(dis!=null){
    try {
     dis.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  }
  
 }
 private static DataInputStream DataInputStream() {
  // TODO Auto-generated method stub
  return null;
 }
 public static void main(String[] args) {
  writeData();//binary로 생겨서 editor로 안읽힌다.
  readData();//파일로부터 저장되어있는 값을 읽어 들인다.
 }
 
}

--------------------
==========================================================================

* 예제
Human h = new Human("홍길동",20,'B',170.9,new AddressDTO("111-222","서울특별시 송파구");
DataOutStream dos = new DataOuputStream(new FileOutputStream("human.dat");
dos.writeUTF(h.getName());
dos.writeInt(h.getAge());
dos.writeUTF(h.getAddress().getZipCode());

* ObjectInputStream   -           입력 -> 객체 역직렬화
                       |- 객체를  입출력 하기위한 기능을 제공
  ObjectOutputStream  -           출력 -> 객체 직렬화

- java.io - Serializable를 implements한 class의 객체들만 직렬화 할 수 있다. (크게 공통점이 없는 것들을 하나의 것으로 만들어 주는 것이 인터페이스다. 뒤에 able이 붙는다.)
                 

       직렬화
name = "홍길동"   --------------------> 홍길동 10 b 180
age = 10;         <--------------------
bloodType = 'b'      역직렬화
tall = 180

package : day27

* project : day27
  package : file.io.filter
  class : ObjectStreamTest
   PersonDTO

package file.io.filter;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;

public class ObjectStreamTest {
 private static String fileName = "d:\\person.obj";
 public static void wrtiteObject(Object obj){
  //인수로 받은 객체를 person.obj에 출력
  //ObjectOutputStream 이용. 객체를 출력 - 객체 직렬화,
  //                                            출력대상 :  instance변수의 값(attribute)
  ObjectOutputStream oos = null;
  try {
   //연결 + 필터
   oos = new ObjectOutputStream(new FileOutputStream(fileName));
   //쓰기 - writeObject(object)
   oos.writeObject(obj);
   
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  }finally{
   if (oos != null) {
    try {
     oos.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  }
 }
 public static Object readObject(){
  //Person.obj파일에 저장된 객체 정보를 읽어 들여 다시 객체로 만든다.
  //ObjectInputStream - 객체를 입력받는 메소드 : 객체 역직렬화
  //메소드 : readObject() ; Object
  ObjectInputStream ois = null;
  Object obj = null;
  //연결 + 필터
  try {
   ois = new ObjectInputStream(new FileInputStream(fileName));
   //읽기
   obj = ois.readObject();
  } catch (FileNotFoundException e) {
   e.printStackTrace();
  } catch (IOException e) {
   e.printStackTrace();
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  }finally{
   if (ois != null) {
    try {
     ois.close();
    } catch (IOException e) {
     e.printStackTrace();
    }
   }
  }
  return obj;
 }
 public static void main(String[] args) {
  AddressDTO address = new AddressDTO("111-222","서울시 송파구 가락동");
  PersonDTO p = new PersonDTO("id-111","1111","홍길동",20,address);
  wrtiteObject(p);
  Object obj = readObject();
  PersonDTO pto = (PersonDTO) obj;
  System.out.println(pto);
 }
}

-------------------
package file.io.filter;

import java.io.Serializable;

public class PersonDTO implements Serializable{
 private String id;
 private String password;
 private String name;
 private int age;
 private AddressDTO address;
 //생성자, setter/getter, toString
 public PersonDTO() {
 }
 public PersonDTO(String id, String password, String name, int age) {
  this.id = id;
  this.password = password;
  this.name = name;
  this.age = age;
 }

 public PersonDTO(String id, String password, String name, int age,
   AddressDTO address) {
  this.id = id;
  this.password = password;
  this.name = name;
  this.age = age;
  this.address = address;
 }
 public AddressDTO getAddress() {
  return address;
 }
 public void setAddress(AddressDTO address) {
  this.address = address;
 }
 public String getId() {
  return id;
 }
 public void setId(String id) {
  this.id = id;
 }
 public String getPassword() {
  return password;
 }
 public void setPassword(String password) {
  this.password = password;
 }
 public String getName() {
  return name;
 }
 public void setName(String name) {
  this.name = name;
 }
 public int getAge() {
  return age;
 }
 public void setAge(int age) {
  this.age = age;
 }
 @Override
 public String toString() {
  return "PersonDTO [id=" + id + ", password=" + password + ", name="
    + name + ", age=" + age + ", address=" + address + "]";
 }
 
}

-----------------------
package file.io.filter;

import java.io.Serializable;

public class AddressDTO implements Serializable{
 private String zipcode;
 private String address;
 //생성자, setter/getter, toString
 public AddressDTO(String zipcode, String address) {
  this.zipcode = zipcode;
  this.address = address;
 }
 public String getZipcode() {
  return zipcode;
 }
 public void setZipcode(String zipcode) {
  this.zipcode = zipcode;
 }
 public String getAddress() {
  return address;
 }
 public void setAddress(String address) {
  this.address = address;
 }
 @Override
 public String toString() {
  return "AddressDTO [zipcode=" + zipcode + ", address=" + address + "]";
 }
 
}

//결과 : PersonDTO [id=id-111, password=1111, name=홍길동, age=20, address=AddressDTO [zipcode=111-222, address=서울시 송파구 가락동]]