JAVA TECHNOLOGY

Hashtable:- Hashtable is a legacy class where object store in the form of key value pairs but key cannot be null as well as values cannot be null. All the methods of Hashtable class are synchronized. Example1:- TestHashtable.java import java.util.*; class TestHashtable { public static void main(String[]args) { Hashtable<Object,Object> m=new Hashtable<Object,Object>(); m.put(101,"Sumit"); m.put(104,"Sunita"); m.put(102,"Suman"); m.put(107,"Sonu"); Set s=m.entrySet(); Iterator itr=s.iterator(); System.out.println("Key   :::::::::Value"); while(itr.hasNext()) { Map.Entry me=(Map.Entry)itr.next(); System.out.println(me.getKey()+"    :::: "+me.getValue()); } } } Output:- Key   :::::::::Value 107    :::: Sonu 104    :::: Sunita 102    :::: Suman 101    :::: Sumit Example2:- TestHashtable.java import java.util.*; class TestH...