Java Best Program

How to delete user defined objects as a key from Linked HashMap

package com.java2novice.linkedhashmap;

import java.util.LinkedHashMap;

import java.util.Set;

public class MyDeleteKeyObject

{

public static void main(String a[])

{

        LinkedHashMap hm = new LinkedHashMap();

        hm.put(new Price("Banana", 20), "Banana");

        hm.put(new Price("Apple", 40), "Apple");

        hm.put(new Price("Orange", 30), "Orange");

        printMap(hm);

        Price key = new Price("Banana", 20);

        System.out.println("Deleting key...");

        hm.remove(key);

        System.out.println("After deleting key:");

        printMap(hm);

    }

  public static void printMap(LinkedHashMap map)

  {

        Set keys = map.keySet();

        for(Price p:keys)

       {

            System.out.println(p+"==>"+map.get(p));

        }

    }

}

class Price

{

    private String item;

    private int price;

 public Price(String itm, int pr)

{

        this.item = itm;

        this.price = pr;

 }

 public int hashCode()

{

        System.out.println("In hashcode");

        int hashcode = 0;

        hashcode = price*20;

        hashcode += item.hashCode();

        return hashcode;

  }

  public boolean equals(Object obj)

 {

        System.out.println("In equals");

        if (obj instanceof Price)

       {

            Price pp = (Price) obj;

            return (pp.item.equals(this.item) && pp.price == this.price);

        }

         else

        {

            return false;

        }

    }

  public String getItem()

  {

        return item;

   }

  public void setItem(String item)

  {

        this.item = item;

    }

  public int getPrice()

   {

        return price;

    }

  public void setPrice(int price)

  {

        this.price = price;

    }

  public String toString()

  {

        return "item: "+item+"  price: "+price;

    }

}

How to add all elements to the given collection object

package com.java2novice.collections;

import java.util.ArrayList;

import java.util.Collections;

import java.util.List;

public class CollectionsAddAll

{

public static void main(String a[])

{

        List myList = new ArrayList();

        myList.add("java");

        myList.add("c");

        myList.add("c++");

        System.out.println("Initial list:"+myList);

        Collections.addAll(myList, "perl","php");

        System.out.println("After adding elements:"+myList);

        String[] strArr = {".Net", "unix"};

        Collections.addAll(myList, strArr);

        System.out.println("After adding array:"+myList);

    }

}

Write an example for Collections.as LifoQueue() method

package com.java2novice.collections;

import java.util.ArrayDeque;

import java.util.Collections;

import java.util.Deque;

import java.util.Queue;

public class CollectionAsLifoQueue

{

public static void main(String args[])

{

           Deque dq = new ArrayDeque(5);

          dq.add("java");

          dq.add("c");

          dq.add("c++");

          dq.add("unix");

          dq.add("perl");       

          Queue q = Collections.asLifoQueue(dq);  

          System.out.println("returned queue is: "+q);

       }

}