ObjectInputStream

package Aug14.IO;



import java.io.*;
import java.util.*;
import java.util.Map.Entry;

class Student<T> implements Serializable{
    private T rollNo;
    
    Student(T rollNo){
        this.rollNo=rollNo;
    }
    
    private String Name;int age;
    
    public void setRollNo(T roll){
        rollNo=roll;
    }
    
    public T getRollNo(){
        return rollNo;
    }
    
    public void setName(String roll){
        Name=roll;
    }
    
    public String getName(){
        return Name;
    }

    public void setAge(int roll){
        age=roll;
    }
    
    public int getAge(){
        return age;
    }

    public String toString(){
        return "Name:- "+getName()+" Age:- "+getAge();
    }
}


public  class StudDataFile {
    
    private void objectWriter(Map<String, Student<Integer>> m) {
        try{
            File f=new File("D:\\Students.txt");
            ObjectOutputStream oos=new ObjectOutputStream(
                    new FileOutputStream(f,true));
            oos.writeObject(m);
            oos.flush();
            oos.close();
            System.out.println("File Writing Success");
        }catch(Exception e){
            e.printStackTrace();
        }
    }
    
    private void objectReader(){
        try{
            File f=new File("D:\\Students.txt");
            ObjectInputStream ois=new ObjectInputStream(new FileInputStream(f));
            
            Map<String, Student<Integer>> m=(Map<String, Student<Integer>>)ois.readObject();
            
            Set view=m.entrySet();
            Iterator it=view.iterator();
            while(it.hasNext())
            {
                Map.Entry<String, Student<Integer>> stud = (Entry<String, Student<Integer>>) it.next();
                System.out.println("Key:- "+stud.getKey()+"\tValues:- "+stud.getValue());
            }
            ois.close();
        }catch(Exception e){
            e.printStackTrace();
        }
        System.out.println("File Reading Success");
    }

    public static void main(String[] args) {
        Map<String, Student<Integer>> stuData=new HashMap<String, Student<Integer>>();
        
        Student<Integer> s;
        for(int i=0; i<5; i++){
            s=new Student<Integer>(i+1);
            s.setName("Student: "+(i+1));
            s.setAge(20);
            stuData.put("st"+(i+1),s);
        }
        
        StudDataFile sf=new StudDataFile();
        sf.objectWriter(stuData);
        sf.objectReader();
    }

}