How to Search for Product with least cost from List? I have a List of Speakers in List. I want to get the speaker with the least cost.

Speakers.java

package com.mugil.bean;

public class Speakers {
 private Integer speakerID;
 private String companyName;
 private Integer price;
 private String sellerName;

 public Speakers(Integer pSpeakerId, String pcompanyName, Integer pPrice, String psellerName) {
  this.speakerID = pSpeakerId;
  this.companyName = pcompanyName;
  this.price = pPrice;
  this.sellerName = psellerName;
 }

 public int getSpeakerID() {
  return speakerID;
 }
 public void setSpeakerID(int speakerID) {
  this.speakerID = speakerID;
 }
 public String getCompanyName() {
  return companyName;
 }
 public void setCompanyName(String companyName) {
  this.companyName = companyName;
 }
 public int getPrice() {
  return price;
 }
 public void setPrice(int price) {
  this.price = price;
 }

 public String getSellerName() {
  return sellerName;
 }

 public void setSellerName(String sellerName) {
  this.sellerName = sellerName;
 }

 @Override
 public String toString() {
  return "Speakers [speakerID=" + speakerID + ", companyName=" + companyName + ", price=" + price +
   ", sellerName=" + sellerName + "]";
 }
}

SearchSpeakers.java

package com.mugil.test;

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.stream.Collector;
import java.util.stream.Collectors;

import com.mugil.bean.Speakers;

public class SearchSpeakers {

 public static void main(String[] args) {
  Speakers objSpeaker1 = new Speakers(101, "JBL Go", 120, "Amazon");
  Speakers objSpeaker2 = new Speakers(102, "Panasonic", 420, "Amazon");
  Speakers objSpeaker3 = new Speakers(103, "JBL Go", 900, "Flipkart");
  Speakers objSpeaker4 = new Speakers(104, "JBL Go", 120, "Amazon");
  Speakers objSpeaker5 = new Speakers(105, "JBL Go", 350, "Amazon");
  Speakers objSpeaker6 = new Speakers(101, "Philips", 120, "EBay");
  Speakers objSpeaker7 = new Speakers(102, "JBL Go", 125, "Ebay");
  Speakers objSpeaker8 = new Speakers(103, "JBL Go", 35, "Smart Shoppe");
  Speakers objSpeaker9 = new Speakers(104, "Panasonic", 80, "Amazon");
  Speakers objSpeaker10 = new Speakers(105, "Philips", 180, "Amazon");

  List < Speakers > arrSpeakers = new ArrayList < Speakers > ();

  arrSpeakers.add(objSpeaker1);
  arrSpeakers.add(objSpeaker2);
  arrSpeakers.add(objSpeaker3);
  arrSpeakers.add(objSpeaker4);
  arrSpeakers.add(objSpeaker5);
  arrSpeakers.add(objSpeaker6);
  arrSpeakers.add(objSpeaker7);
  arrSpeakers.add(objSpeaker8);
  arrSpeakers.add(objSpeaker9);
  arrSpeakers.add(objSpeaker10);

  Comparator < Speakers > spkComparator = (Speakers objSpeaker1a, Speakers objSpeaker2a) -> objSpeaker1a.getPrice() - objSpeaker2a.getPrice();

  arrSpeakers.stream().sorted(spkComparator).collect(Collectors.groupingBy(Speakers::getCompanyName)).values()
   .stream().forEach(searchedModel -> System.out
    .println("Speaker with Lowest Cost" + searchedModel.stream().findFirst()));
 }
}

arrSpeakers.stream().sorted(spkComparator).collect(Collectors.groupingBy(Speakers::getCompanyName)).values()
   .stream().forEach(searchedModel -> System.out
    .println("Speaker with Lowest Cost" + searchedModel.stream().findFirst()));

arrSpeakers.stream() – Convert to Stream
arrSpeakers.stream().sorted(spkComparator) – Sorts the list by price
arrSpeakers.stream().sorted(spkComparator).collect(Collectors.groupingBy(Speakers::getCompanyName)) – Groups the Sorted List by Company Name
arrSpeakers.stream().sorted(spkComparator).collect(Collectors.groupingBy(Speakers::getCompanyName)).values()
.stream() – Convert the Sorted List into Stream

The above code could be rewritten as follows

//Sort by Price and group by company name
Stream objStream = arrSpeakers.stream()
                              .sorted(spkComparator)
                              .collect(Collectors.groupingBy(Speakers::getCompanyName)).values();

//Loop through Stream of List and print the first one
objStream.forEach(listOfStudent -> System.out.println((ArrayList)listOfStudent.stream().findFirst()));

Output

Speaker with Lowest CostOptional[Speakers [speakerID=101, companyName=Philips, price=120, sellerName=EBay]]
Speaker with Lowest CostOptional[Speakers [speakerID=104, companyName=Panasonic, price=80, sellerName=Amazon]]
Speaker with Lowest CostOptional[Speakers [speakerID=103, companyName=JBL Go, price=35, sellerName=Smart Shoppe]]