Sort Operator in Lambda Expression in Java 8

Create Product class

package pmk.learnjava8withrealapps.lambda;

public class Product {

	private String id;
	private String name;
	private long price;
	private int quantity;
	private String manufacturer;

	public String getManufacturer() {
		return manufacturer;
	}

	public void setManufacturer(String manufacturer) {
		this.manufacturer = manufacturer;
	}

	public String getId() {
		return id;
	}

	public void setId(String id) {
		this.id = id;
	}

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public long getPrice() {
		return price;
	}

	public void setPrice(long price) {
		this.price = price;
	}

	public int getQuantity() {
		return quantity;
	}

	public void setQuantity(int quantity) {
		this.quantity = quantity;
	}

	public Product(String id, String name, long price, int quantity, String manufacturer) {
		this.id = id;
		this.name = name;
		this.price = price;
		this.quantity = quantity;
		this.manufacturer = manufacturer;
	}

	public Product() {
	}

	@Override
	public String toString() {
		return "Id: " + this.id + "\nName: " + this.name + "\nPrice: " + this.price + "\nQuantity: " + this.quantity + "\nManufacturer: " + this.manufacturer;
	}

}

Use Sort Operator in Lambda Expression

package pmk.learnjava8withrealapps.lambda;

import java.util.ArrayList;
import java.util.List;

public class Demo {

	public static void main(String[] args) {

		List products = new ArrayList();
		products.add(new Product("p1", "mobile 1", 1000, 2, "Manufacturer 1"));
		products.add(new Product("p2", "mobile 2", 700, 4, "Manufacturer 1"));
		products.add(new Product("p3", "laptop 1", 1200, 6, "Manufacturer 2"));
		products.add(new Product("p4", "laptop 2", 7000, 9, "Manufacturer 2"));
		products.add(new Product("p5", "laptop 3", 2300, 9, "Manufacturer 2"));

		System.out.println("Ascending Order");
		products.stream()
			.sorted((p1, p2) -> (int) (p1.getPrice() - p2.getPrice()))
			.forEach(p -> {
				System.out.println(p.toString());
				System.out.println("======================");
		});

		System.out.println("Descending Order");
		products.stream()
			.sorted((p1, p2) -> (int) (p2.getPrice() - p1.getPrice()))
			.forEach(p -> {
				System.out.println(p.toString());
				System.out.println("======================");
		});

	}
}

Output

Ascending Order
Id: p2
Name: mobile 2
Price: 700
Quantity: 4
Manufacturer: Manufacturer 1
======================
Id: p1
Name: mobile 1
Price: 1000
Quantity: 2
Manufacturer: Manufacturer 1
======================
Id: p3
Name: laptop 1
Price: 1200
Quantity: 6
Manufacturer: Manufacturer 2
======================
Id: p5
Name: laptop 3
Price: 2300
Quantity: 9
Manufacturer: Manufacturer 2
======================
Id: p4
Name: laptop 2
Price: 7000
Quantity: 9
Manufacturer: Manufacturer 2
======================

Descending Order
Id: p4
Name: laptop 2
Price: 7000
Quantity: 9
Manufacturer: Manufacturer 2
======================
Id: p5
Name: laptop 3
Price: 2300
Quantity: 9
Manufacturer: Manufacturer 2
======================
Id: p3
Name: laptop 1
Price: 1200
Quantity: 6
Manufacturer: Manufacturer 2
======================
Id: p1
Name: mobile 1
Price: 1000
Quantity: 2
Manufacturer: Manufacturer 1
======================
Id: p2
Name: mobile 2
Price: 700
Quantity: 4
Manufacturer: Manufacturer 1
======================