hashtable class implementation example code in|with java

hashtable in java hashtable example in java hash table in java hash table implementation in java hash table in java example hashtable in java example code hashtable example in java code

   Hash Table :

               Hash table is one of the sub class of Dictionary, so that all the methods of Dictionary 

         class inherited into Hash Table class. Hash table class organizes the data in the form of 

         (key, value) pairs by following Hashing mechanism.

                 Since it follows hashing mechanism as a java programmer we cannot determine in 

         what order HashTable class object displays the data i.e; undetermined form. The  

         functionality of HashTable is more or less similar to HashMap but HashTable belongs to 

         synchronized and it never allows null values for (key, value) pairs. Whereas HashMap 

         Class object belongs to Non-synchronized and it allows null values for (key, value) pair.

         Creating Hash Table is nothing but creating an object HashTable class object.

     For Example:

        HashTable ht=new HashTable();

    Profile ofHashTable Class :

           1)      HashTable()

           2)      HashTable(int)

           3)      HashTable(int size,float fillratio)

           Limitations of HashTable :

       If we develop any application we are able to maintain user defined data in the form of (key, 

      value) pair and we are unable to develop the following

a)      Unable to read the data from Properties file /resource bundle file.

b)      Unable to read the data from environmental variables.

c)       Unable to develop flexible application.

      

   The Following Program which the concept of HashTable  :

          import java.util.*;

          class htable

         {

            Public static void main(String args[])

           {

              HashTable ht=new HashTable();

           //add the data ( key,value) as(state ,capital) to ht

               ht.put(“AP”,”HYD”);

               ht.put(“TN”,”CHN”);

               ht.put(“KT”,”BANG”);

               Enumeration e=ht.keys();

                While(e.hasMoreElements())

               {

                  Object kobj=e.nextElement();

                  Object vobj=ht.get(kobj);

                  System.out.println(kobj+”-----------“+vobj);

               }

                If(args.length==0)

              {

                    System.out.println(“PLZ ENTER THE STATE”);

                }

               else

               {

                     String state=args[]0].toUpperCase();

                    Object cap=ht.get(state);

               

                    If(cap!=null)

                 {

                    System.out.println(cap+”is capital of “+state);

                  }

                 else

                 {

                    System.out.println(“Capital is not found”);

                  }
  

                }

              }

         Data Extraction Interfaces are as follows :

•       Iterator (I)
•       ListIterator(I)
•       Enumeration (I).

          1- D and 2-D Collection Frame work classes are 

     

•          LinkedList 
•           ArrayList
•           HashSet
•           TreeSet
•           HashMap
•           TreeMap
•           Vector 
•           Stack  
•           Dictionary 
•           Properties

        To read the values dynamically from keyboard their is a class.

                 Java.util.Scanner or Scanner class