#Student.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 lesson03;

import java.io.Serializable;

/**
 *
 * @author Diep.Tran
 */
public class Student implements Serializable{
    String fullname, email, address;

    public Student() {
    }

    public Student(String fullname, String email, String address) {
        this.fullname = fullname;
        this.email = email;
        this.address = address;
    }

    public String getFullname() {
        return fullname;
    }

    public void setFullname(String fullname) {
        this.fullname = fullname;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    @Override
    public String toString() {
        return "Student{" + "fullname=" + fullname + ", email=" + email + ", address=" + address + "}\n";
    }
    
    public String getFileLine() {
        return fullname + "," + email + "," + address + "\n";
    }
    
    public void parseFileLine(String line) {
        try {
            String[] params = line.split(",");
            fullname = params[0];
            email = params[1];
            address = params[2];
        } catch(Exception e) {}
    }
}

#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 lesson03;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author Diep.Tran
 */
public class Main {
    public static void main(String[] args) {
        //testFile();
        //saveTextFile1();
        //readTextFile1();
        //readTextFile2();
        //saveStudentIntoFile();
        //readStudentFromFile();
        //saveStudent();
        readStudent();
    }
    
    static void readStudent() {
        List<Student> studentList;
        
        FileInputStream fis = null;
        ObjectInputStream ois = null;
        
        try {
            fis = new FileInputStream("data/student.obj");
            ois = new ObjectInputStream(fis);
            
            studentList = (List<Student>) ois.readObject();
            
            for (Student student : studentList) {
                System.out.println(student);
            }
        } 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);
        } catch (ClassNotFoundException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        } finally {
            if(fis != null) {
                try {
                    fis.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(ois != null) {
                try {
                    ois.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
    }
    
    static void saveStudent() {
        List<Student> studentList = new ArrayList<>();
        studentList.add(new Student("A", "A@gmail.com", "Ha Noi"));
        studentList.add(new Student("B", "B@gmail.com", "Nam Dinh"));
        studentList.add(new Student("C", "C@gmail.com", "Ha Noi"));
        
        FileOutputStream fos = null;
        ObjectOutputStream oos = null;
        
        try {
            fos = new FileOutputStream("data/student.obj");
            oos = new ObjectOutputStream(fos);
            
            oos.writeObject(studentList);
        } 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(fos != null) {
                try {
                    fos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(oos != null) {
                try {
                    oos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
    }
    
    static void readStudentFromFile() {
        FileReader reader = null;
        BufferedReader bufferedReader = null;
        List<Student> studentList = new ArrayList<>();
        
        try {
            reader = new FileReader("data/student.txt");
            bufferedReader = new BufferedReader(reader);
            
            String line;
            while((line = bufferedReader.readLine()) != null) {
                if(line.isEmpty()) continue;
                Student std = new Student();
                std.parseFileLine(line);
                
                studentList.add(std);
            }
            
            for (Student student : studentList) {
                System.out.println(student);
            }
        } 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(reader != null) {
                try {
                    reader.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
    }
    
    static void saveStudentIntoFile() {
        List<Student> studentList = new ArrayList<>();
        studentList.add(new Student("A", "A@gmail.com", "Ha Noi"));
        studentList.add(new Student("B", "B@gmail.com", "Nam Dinh"));
        studentList.add(new Student("C", "C@gmail.com", "Ha Noi"));
        
        FileOutputStream fos = null;
        Scanner scan = new Scanner(System.in);
        
        try {
            //Open connection to File
            fos = new FileOutputStream("data/student.txt");
            
            //For -> duyet tung sv.
            //Fullname Email Address
            for (Student student : studentList) {
                String line = student.getFileLine();
                byte[] data = line.getBytes("utf8");
                
                fos.write(data);
            }
        } catch (FileNotFoundException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        } catch (UnsupportedEncodingException 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(fos != null) {
                try {
                    fos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
    }
    
    static void readTextFile2() {
        FileReader reader = null;
        BufferedReader bufferedReader = null;
        StringBuilder builder = new StringBuilder();
        
        try {
            reader = new FileReader("data/f1.txt");
            bufferedReader = new BufferedReader(reader);
            
            String line;
            while((line = bufferedReader.readLine()) != null) {
                builder.append(line + "\n");
            }
            
            System.out.println(builder.toString());
        } 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(reader != null) {
                try {
                    reader.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
            if(bufferedReader != null) {
                try {
                    bufferedReader.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
    }
    
    static void readTextFile1() {
        FileInputStream fis = null;
        StringBuilder builder = new StringBuilder();
        
        try {
            fis = new FileInputStream("data/f1.txt");
            
            int code;
            while((code = fis.read()) != -1) {
                builder.append((char) code);
            }
            
            System.out.println(builder.toString());
        } 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(fis != null) {
                try {
                    fis.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
    }
    
    static void saveTextFile1() {
        FileOutputStream fos = null;
        Scanner scan = new Scanner(System.in);
        
        try {
            //Open connection to File
            fos = new FileOutputStream("data/f1.txt", true);
            
            //Read/Write data.
            //C1. Luu 1 String to File
            //String str = "\nSinh vien lop C2009G - Aptech 54 Le Thanh Nghi";
            //byte[] data = str.getBytes("utf8");
            //fos.write(data);
            
            //C2. Luu String dc nhap tu ban phim
            String line;
            do {
                System.out.println("Nhap chuoi can them vao File: ");
                line = scan.nextLine() + "\n";
                
                byte[] data = line.getBytes("utf8");
                fos.write(data);
                
                System.out.println("Ban muon tiep tuc khong Y/n? ");
                line = scan.nextLine();
            } while (!line.equalsIgnoreCase("N"));
        } catch (FileNotFoundException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        } catch (UnsupportedEncodingException 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(fos != null) {
                try {
                    fos.close();
                } catch (IOException ex) {
                    Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
        }
    }
    
    static void testFile() {
        File file = new File("data");
        File f2 = new File("data/test.txt");
        
        if(file.isDirectory()) {
            System.out.println("Folder");
        } else {
            System.out.println("File");
        }
        
        if(f2.exists()) {
            System.out.println("File is existing");
        } else {
            System.out.println("Not found");
            try {
                f2.createNewFile();
            } catch (IOException ex) {
                Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
            }
        }
        
        System.out.println(file.getAbsolutePath());
        try {
            System.out.println(file.getCanonicalPath());
        } catch (IOException ex) {
            Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex);
        }
        
        //Duyet folder
        File f3 = new File("./");
        File[] list = f3.listFiles();
        for (File f : list) {
            if(f.isFile()) {
                System.out.println("File > " + f.getName());
            } else {
                System.out.println("> Folder: " + f.getName());
            }
        }
    }
}