#Book.java

/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package com.gokisoft.lesson02;

import java.io.Serializable;
import java.util.Scanner;

/**
 *
 * @author teacher
 */
public class Book implements Serializable{
    String name;
    int price;

    public Book() {
    }

    public Book(String name, int price) {
        this.name = name;
        this.price = price;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "name=" + name + ", price=" + price;
    }
    
    public void parseData(String line){
        //parse
    }
    
    public void display() {
        System.out.println(this);
    }
    
    public void input() {
        Scanner scan = new Scanner(System.in);
        
        System.out.println("Nhap ten: ");
        name = scan.nextLine();
        
        System.out.println("Nhap gia: ");
        price = Integer.parseInt(scan.nextLine());
    }
}

#Main.java

/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package com.gokisoft.lesson02;

import java.io.BufferedWriter;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author teacher
 */
public class Main {

    public static void main(String[] args) {
        //testWriteFile();
//        testWriteObject();
        testReadObject();
    }

    private static void testWriteFile() {
        FileWriter writer = null;
        BufferedWriter bufferedWriter = null;

        try {
            writer = new FileWriter("vidu.txt");
            bufferedWriter = new BufferedWriter(writer);

            //Test write (unicode -> OK)
            String line = "SINH VIEN APTECH 19 LE THANH NGHI\n";
            bufferedWriter.write(line);
        } catch (IOException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            if (bufferedWriter != null) {
                try {
                    bufferedWriter.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }

            if (writer != null) {
                try {
                    writer.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
    }

    private static void testWriteObject() {
        //Mang Book
        List<Book> dataList = new ArrayList<>();
        for (int i = 0; i < 3; i++) {
            Book b = new Book();
            b.input();

            dataList.add(b);
        }

        //Lam the nao -> save data vao file
        //Cach 1: Luu ca mang vao luon
        FileOutputStream fos = null;
        ObjectOutputStream oos = null;

        try {
            fos = new FileOutputStream("vidu2.dat");
            oos = new ObjectOutputStream(fos);

            //Luu ca mang
//            oos.writeObject(dataList);
            for (Book book : dataList) {
                oos.writeObject(book);
            }
        } catch (FileNotFoundException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            if (oos != null) {
                try {
                    oos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }

            if (fos != null) {
                try {
                    fos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
        //End write
    }

    private static void testReadObject() {
        List<Book> dataList;

        FileInputStream fis = null;
        ObjectInputStream ois = null;

        try {
            fis = new FileInputStream("vidu2.dat");
            ois = new ObjectInputStream(fis);

//            dataList = (List<Book>) ois.readObject();
            Book b;
            dataList = new ArrayList<>();
            while(true) {
                try {
                    b = (Book) ois.readObject();
                } catch(IOException | ClassNotFoundException e) {
                    break;
                }
                dataList.add(b);
            }

            for (Book book : dataList) {
                book.display();
            }
        } catch (FileNotFoundException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            if (ois != null) {
                try {
                    ois.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }

            if (fis != null) {
                try {
                    fis.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }

        //End file
    }
}

#readme.txt

Nội dung kiến thức:
	- File
		FileWriter/BufferedWriter
		Read/Write Object -> File
	- Zip
		- Zip file lúc đọc
		- Zip file lúc ghi
		- Unzip file lúc đọc
		- Unzip file lúc ghi
=====================================================
4 bytes -> 1 ky tu
32bit -> 2^32 ky tu khac nhau -> font (unicode)
30 ky tu khac nhau -> trong file vidu.txt
30 -> 2^5 = 32 ky tu khac nhau

A-> 00001
B-> 00010
C-> 00011
...
...

File Zip -> table hash

Unzip -> 5bit -> 1 ky -> kiem tra trong table hash -> ky tu gi -> unicode

#Test.java

/*
 * Click nbfs://nbhost/SystemFileSystem/Templates/Licenses/license-default.txt to change this license
 * Click nbfs://nbhost/SystemFileSystem/Templates/Classes/Class.java to edit this template
 */
package com.gokisoft.lesson02;

import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.util.zip.DeflaterInputStream;
import java.util.zip.DeflaterOutputStream;
import java.util.zip.InflaterInputStream;

/**
 *
 * @author teacher
 */
public class Test {
    public static void main(String[] args) {
//        testZip1();
//        testZip2();
        testUnzip1();
    }
    
    private static void testUnzip1() {
        FileInputStream fis = null;
        InflaterInputStream iis = null;
        FileOutputStream fos = null;
        
        try {
            fis = new FileInputStream("vidu1.def");
            iis = new InflaterInputStream(fis);
            int code;
            
            fos = new FileOutputStream("vidu1-unzip.txt");
            
            while((code = iis.read()) != -1) {
                fos.write(code);
            }
        } catch (FileNotFoundException ex) {
            Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            if(iis != null) {
                try {
                    iis.close();
                } catch (IOException ex) {
                    Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(fis != null) {
                try {
                    fis.close();
                } catch (IOException ex) {
                    Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(fos != null) {
                try {
                    fos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
        //End
    }
    
    private static void testZip2() {
        FileInputStream fis = null;
        FileOutputStream fos = null;
        DeflaterOutputStream dos = null;
        
        try {
            fis = new FileInputStream("vidu.txt");
            int code;
            
            fos = new FileOutputStream("vidu-unzip1.txt");
            dos = new DeflaterOutputStream(fos);
            
            while((code = fis.read()) != -1) {
                dos.write(code);
            }
        } catch (FileNotFoundException ex) {
            Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            if(fis != null) {
                try {
                    fis.close();
                } catch (IOException ex) {
                    Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(dos != null) {
                try {
                    dos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(fos != null) {
                try {
                    fos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
        //End
    }
    
    private static void testZip1() {
        FileInputStream fis = null;
        DeflaterInputStream dis = null;
        FileOutputStream fos = null;
        
        try {
            fis = new FileInputStream("vidu.txt");
            dis = new DeflaterInputStream(fis);
            int code;
            
            fos = new FileOutputStream("vidu1.def");
            
            while((code = dis.read()) != -1) {
                fos.write(code);
            }
        } catch (FileNotFoundException ex) {
            Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            if(dis != null) {
                try {
                    dis.close();
                } catch (IOException ex) {
                    Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(fis != null) {
                try {
                    fis.close();
                } catch (IOException ex) {
                    Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(fos != null) {
                try {
                    fos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Test.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
        //End
    }
}