package test;
 
import java.util.Hashtable;
import java.util.Vector;
import java.io.*;
 
public class HashTableTest {
  private static String fileName = "persondata.dat";
  public static void main(String[] args) {
   storeTable();
   restoreTable();
  }
public static void restoreTable() {
    try {
      FileInputStream in = new FileInputStream(fileName);
      ObjectInputStream s = new ObjectInputStream(in);
      Hashtable ht = (Hashtable) s.readObject();
      System.out.println ( "Restored:" + ht) ;
    }
    catch (Exception e){
      System.out.println (e.getMessage()) ;
    }
 
 }
 
 public static void storeTable() {
   Hashtable ht = new Hashtable();
   Vector v1 = new Vector();
   Vector v2 = new Vector();
 
   v1.add(new Person (101, "John"));
   v1.add(new Person (102, "Mary"));
 
   v2.add(new Person (201, "Bill"));
   v2.add(new Person (202, "Ed"));
 
   ht.put("set1", v1);
   ht.put("set2", v2);
 try {
   FileOutputStream out = new FileOutputStream(fileName);
   ObjectOutputStream s = new ObjectOutputStream(out);
   s.writeObject(ht);
   s.flush();
   System.out.println("Stored:" + ht);
 }
 catch ( Exception e){
   System.out.println(e.getMessage());
 }
 }
}
 
class Person implements java.io.Serializable {
  private String name;
  private int id ;
 
 public Person ( int id, String name){
   this.id = id;
   this.name = name;
 }
  public String toString() {
    return name + "(" + id + ")";
  }
}