Adapter Pattern example

Adapter Pattern

It helps to assign/convert one interface (called as source) to another distinct interface (called as target).

Example Description:

The below code helps us to use legacy Enumeration class available in Vector class in place of modern Iterator class.

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package designpattern;   import java.util.Enumeration; import java.util.Iterator; import java.util.Vector;   /**  *  * @author DELL  */ public class AdapterPatternExample {       public static void main(String[] args) {         demo();     }       public static void demo() {         Vector namelist = new Vector();         namelist.add("Athiruban");         namelist.add("Athinivas");         Enumeration legacyIterator = namelist.elements();         Iterator iterator;           LegacyIteratorAdapter adapter = new LegacyIteratorAdapter(legacyIterator);         //iterator = legacyIterator;    /* this code will fail */         iterator = adapter;         for (; iterator.hasNext();) {             System.out.println(iterator.next().toString());         }     } }   class LegacyIteratorAdapter implements Iterator {     /*      * The purpose of the class to adapt the legacy Enumeration interface to      * modern Iterator interface.      */       Enumeration legacyIterator;       public LegacyIteratorAdapter(Enumeration e) {         legacyIterator = e;     }       @Override     public boolean hasNext() {         return legacyIterator.hasMoreElements();     }       @Override     public Object next() {         return legacyIterator.nextElement();     }       @Override     public void remove() {         throw new UnsupportedOperationException("Not supported yet."); //To change body of generated methods, choose Tools | Templates.     } }