How to Find Distinct Element Using POJO Class Java With Example?

Distinct Element Using POJO Class Java

Write a Program to Find Distinct Element Using POJO [Getter & Setter] Class Java?

package com.java.Softwaretestingblog;
import java.util.HashSet;
public class FindDistinctElement {
   public static void main(String[] args) {
      // TODO Auto-generated method stub
      HashSet<Price> lhm = new HashSet<Price>();
      lhm.add(new Price("Banana", 20));
      lhm.add(new Price("Apple", 40));
      lhm.add(new Price("Orange", 30));
      for(Price pr:lhm){
         System.out.println(pr);
      }
      Price duplicate = new Price("Banana", 20);
      System.out.println("inserting duplicate object...");
      lhm.add(duplicate);
      System.out.println("After insertion:");
      for(Price pr:lhm){
         System.out.println(pr);
      }
   }
}
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) &amp;&amp; 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;
   }
}

Output:

In hashcode
In hashcode
In hashcode
item: Apple price: 40
item: Orange price: 30
item: Banana price: 20
inserting duplicate object...
In hashcode
In equals
After insertion:
item: Apple price: 40
item: Orange price: 30
item: Banana price: 20

Reference: Article