1 package Aug14.IO;  2   3   4   5 import java.io.*;  6 import java.util.*;  7 import java.util.Map.Entry;  8   9 class Student<T> implements Serializable{ 10     private T rollNo; 11      12     Student(T rollNo){ 13         this.rollNo=rollNo; 14     } 15      16     private String Name;int age; 17      18     public void setRollNo(T roll){ 19         rollNo=roll; 20     } 21      22     public T getRollNo(){ 23         return rollNo; 24     } 25      26     public void setName(String roll){ 27         Name=roll; 28     } 29      30     public String getName(){ 31         return Name; 32     } 33  34     public void setAge(int roll){ 35         age=roll; 36     } 37      38     public int getAge(){ 39         return age; 40     } 41  42     public String toString(){ 43         return "Name:- "+getName()+" Age:- "+getAge(); 44     } 45 } 46  47  48 public  class StudDataFile { 49      50     private void objectWriter(Map<String, Student<Integer>> m) { 51         try{ 52             File f=new File("D:\\Students.txt"); 53             ObjectOutputStream oos=new ObjectOutputStream( 54                     new FileOutputStream(f,true)); 55             oos.writeObject(m); 56             oos.flush(); 57             oos.close(); 58             System.out.println("File Writing Success"); 59         }catch(Exception e){ 60             e.printStackTrace(); 61         } 62     } 63      64     private void objectReader(){ 65         try{ 66             File f=new File("D:\\Students.txt"); 67             ObjectInputStream ois=new ObjectInputStream(new FileInputStream(f)); 68              69             Map<String, Student<Integer>> m=(Map<String, Student<Integer>>)ois.readObject(); 70              71             Set view=m.entrySet(); 72             Iterator it=view.iterator(); 73             while(it.hasNext()) 74             { 75                 Map.Entry<String, Student<Integer>> stud = (Entry<String, Student<Integer>>) it.next(); 76                 System.out.println("Key:- "+stud.getKey()+"\tValues:- "+stud.getValue()); 77             } 78             ois.close(); 79         }catch(Exception e){ 80             e.printStackTrace(); 81         } 82         System.out.println("File Reading Success"); 83     } 84  85     public static void main(String[] args) { 86         Map<String, Student<Integer>> stuData=http://www.mamicode.com/new HashMap<String, Student<Integer>>(); 87          88         Student<Integer> s; 89         for(int i=0; i<5; i++){ 90             s=new Student<Integer>(i+1); 91             s.setName("Student: "+(i+1)); 92             s.setAge(20); 93             stuData.put("st"+(i+1),s); 94         } 95          96         StudDataFile sf=new StudDataFile(); 97         sf.objectWriter(stuData); 98         sf.objectReader(); 99     }100 101 }