Distinct method of Stream class

Example :

package com.demo.java8;

import java.util.Arrays;
import java.util.List;

public class Demo6 {
	public static void main(String[] args) {
		List<Emp6> empList = Arrays.asList(new Emp6[] { 
				new Emp6("1","Mumbai","20"),
				new Emp6("2","Delhi","23"),
				new Emp6("3","Kolkata","25"),
				new Emp6("4","Chennai","18"),
				new Emp6("9","Delhi","22"),
				new Emp6("5","Mumbai","11"),
				new Emp6("6","Kolkata","30"),
				new Emp6("7","Chennai","35"),
				new Emp6("8","Mumbai","15"),
				new Emp6("3","Kolkata","25"),
				new Emp6("6","Kolkata","30"),
				new Emp6("9","Delhi","22"),
				new Emp6("10","Kolkata","27")
				});
		
		empList.stream().map(x->x.getId()).distinct().sorted((e1,e2) -> Integer.parseInt(e1)-Integer.parseInt(e2)).forEach(System.out::println);
	}
}
class Emp6{
	private String id;
	private String city;
	private String age;
	public Emp6(String id, String city, String age) {
		super();
		this.id = id;
		this.city = city;
		this.age = age;
	}
	public String getId() {return id;}
	public String getCity() {return city;}
	public String getAge() {return age;}
	@Override
	public String toString() {
		return "Emp [id=" + id + ", city=" + city + ", age=" + age + "]";
	}
}