#aptech.json

[
  {
    "name": "SEM1",
    "subject-list": [
      {
        "name": "Lap Trinh C",
        "price": 200000,
        "authorName": "TRAN VAN DIEP",
        "manufacturer": "Aptech"
      },
      {
        "name": "Lap Trinh HTML/CSS/JS",
        "price": 100000,
        "authorName": "TRAN VAN DIEP",
        "manufacturer": "Aptech"
      },
      {
        "name": "SQL Server",
        "price": 300000,
        "authorName": "TRAN VAN DIEP",
        "manufacturer": "Aptech"
      }
    ]
  },
  {
    "name": "SEM2",
    "subject-list": [
      {
        "name": "ADF1",
        "price": 200000,
        "authorName": "TRAN VAN DIEP",
        "manufacturer": "Aptech"
      },
      {
        "name": "ADF2",
        "price": 100000,
        "authorName": "TRAN VAN DIEP",
        "manufacturer": "Aptech"
      },
      {
        "name": "XML/JSON",
        "price": 300000,
        "authorName": "TRAN VAN DIEP",
        "manufacturer": "Aptech"
      }
    ]
  }
]

#book-list.json

[
  {
    "name": "Lap Trinh C",
    "price": 200000,
    "authorName": "TRAN VAN DIEP",
    "manufacturer": "Aptech"
  },
  {
    "name": "Lap Trinh HTML/CSS/JS",
    "price": 100000,
    "authorName": "TRAN VAN DIEP",
    "manufacturer": "Aptech"
  },
  {
    "name": "SQL Server",
    "price": 300000,
    "authorName": "TRAN VAN DIEP",
    "manufacturer": "Aptech"
  }
]

#book.json

{
    "name": "Lap Trinh C",
    "price": 200000,
    "authorName": "TRAN VAN DIEP",
    "manufacturer": "Aptech"
}

#Book.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package xml.lesson03;

import org.json.JSONObject;

/**
 *
 * @author Diep.Tran
 */
public class Book {
    String name;
    int price;
    String authorName;
    String manufacturer;

    public Book() {
    }

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

    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;
    }

    public String getAuthorName() {
        return authorName;
    }

    public void setAuthorName(String authorName) {
        this.authorName = authorName;
    }

    public String getManufacturer() {
        return manufacturer;
    }

    public void setManufacturer(String manufacturer) {
        this.manufacturer = manufacturer;
    }

    @Override
    public String toString() {
        return "Book{" + "name=" + name + ", price=" + price + ", authorName=" + authorName + ", manufacturer=" + manufacturer + '}';
    }
    
    public void parseJSON(JSONObject obj) {
        this.name = obj.getString("name");
        this.price = obj.getInt("price");
        this.authorName = obj.getString("authorName");
        this.manufacturer = obj.getString("manufacturer");
    }
}

#GsonTest.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package xml.lesson03;

import com.google.gson.Gson;
import com.google.gson.reflect.TypeToken;
import java.util.List;

/**
 *
 * @author Diep.Tran
 */
public class GsonTest {
    public static void main(String[] args) {
        //parseGson1();
        //parseGson2();
        parseGson3();
    }
    
    static void parseGson1() {
        String content = Utility.getContentFromFile("book.json");
        
        Gson gson = new Gson();
        Book b = gson.fromJson(content, Book.class);
        
        System.out.println(b);
    }
    
    static void parseGson2() {
        String content = Utility.getContentFromFile("book-list.json");
        
        Gson gson = new Gson();
        List<Book> dataList = gson.fromJson(content, new TypeToken<List<Book>>(){}.getType());
        
        dataList.forEach(book -> {
            System.out.println(book);
        });
    }
    
    static void parseGson3() {
        String content = Utility.getContentFromFile("aptech.json");
        
        Gson gson = new Gson();
        List<Semester> dataList = gson.fromJson(content, new TypeToken<List<Semester>>(){}.getType());
        
        dataList.forEach(semester -> {
            semester.display();
        });
        
        Semester semester = new Semester();
        semester.setName("SEM3");
        semester.getBookList().add(new Book("WinForm", 150000, "TRAN VAN A", "APTECH"));
        
        dataList.add(semester);
        
        //Save list -> json
        String json = gson.toJson(dataList);
        
        Utility.saveFile(json, "aptech01.json");
    }
}

#Main.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package xml.lesson03;

import java.util.ArrayList;
import java.util.List;
import org.json.JSONArray;
import org.json.JSONObject;

/**
 *
 * @author Diep.Tran
 */
public class Main {
    public static void main(String[] args) {
        parseJSON2();
    }
    
    static void parseJSON1() {
        String content = Utility.getContentFromFile("book.json");
        
        JSONObject obj = new JSONObject(content);
        Book b = new Book();
        b.parseJSON(obj);
        
        System.out.println(b);
    }
    
    static void parseJSON2() {
        String content = Utility.getContentFromFile("book-list.json");
        
        List<Book> dataList = new ArrayList<>();
        
        JSONArray arr = new JSONArray(content);
        for(int i=0;i<arr.length();i++) {
            JSONObject obj = arr.getJSONObject(i);
            
            Book b = new Book();
            b.parseJSON(obj);
            
            dataList.add(b);
        }
        
        for (Book book : dataList) {
            System.out.println(book);
        }
    }
}

#Semester.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package xml.lesson03;

import com.google.gson.annotations.SerializedName;
import java.util.ArrayList;
import java.util.List;

/**
 *
 * @author Diep.Tran
 */
public class Semester {
    String name;
    
    @SerializedName("subject-list")
    List<Book> bookList;

    public Semester() {
        bookList = new ArrayList<>();
    }

    public String getName() {
        return name;
    }

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

    public List<Book> getBookList() {
        return bookList;
    }

    public void setBookList(List<Book> bookList) {
        this.bookList = bookList;
    }
    
    public void display() {
        System.out.println("Thong tin ky hoc");
        System.out.println("Ky hoc: " + name);
        
        bookList.forEach(book -> {
            System.out.println(book);
        });
    }
}

#Utility.java

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */
package xml.lesson03;

import java.io.BufferedReader;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author Diep.Tran
 */
public class Utility {
    public static String getContentFromFile(String filename) {
        StringBuilder builder = new StringBuilder();
        
        FileReader reader = null;
        BufferedReader bufferedReader = null;
        
        try {
            reader = new FileReader(filename);
            bufferedReader = new BufferedReader(reader);
            
            String line = "";
            while((line = bufferedReader.readLine()) != null) {
                builder.append(line);
            }
        } catch (FileNotFoundException ex) {
            Logger.getLogger(Utility.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(Utility.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            if(reader != null) {
                try {
                    reader.close();
                } catch (IOException ex) {
                    Logger.getLogger(Utility.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException ex) {
                    Logger.getLogger(Utility.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
        
        return builder.toString();
    }
    
    public static void saveFile(String content, String filename) {
        FileOutputStream fos = null;
        
        try {
            fos = new FileOutputStream(filename);
            
            byte[] data = content.getBytes("utf8");
            
            fos.write(data);
        } catch (FileNotFoundException ex) {
            Logger.getLogger(Utility.class.getName()).log(Level.SEVERE, null, ex);
        } catch (UnsupportedEncodingException ex) {
            Logger.getLogger(Utility.class.getName()).log(Level.SEVERE, null, ex);
        } catch (IOException ex) {
            Logger.getLogger(Utility.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            if(fos != null) {
                try {
                    fos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Utility.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
    }
}