Program: How to get highest value element from a set?

To get highest value element of user design objects, we need to implement sorting logic on TreeSet. To implement your own sorting functionality with TreeSet on user defined objects, you have to pass Comparator object along with TreeSet constructor call. The Comparator implementation holds the sorting logic. You have to override compare() method to provide the sorting logic on user defined objects. Now you can get highest value element from set by using last() method depending on your sorting logic.

package com.java2novice.treeset;

import java.util.Comparator;
import java.util.TreeSet;

public class MyHighSalEmp {
	public static void main(String a[]){
		
		TreeSet<Empl2> salComp = new TreeSet<Empl2>(new MySalCompr1());
		salComp.add(new Empl2("Ram",3000));
		salComp.add(new Empl2("John",6000));
		salComp.add(new Empl2("Crish",2000));
		salComp.add(new Empl2("Tom",2400));
		System.out.println("Highest salary emp: "+salComp.last());
	}
}

class MySalCompr1 implements Comparator<Empl2>{

	@Override
	public int compare(Empl2 e1, Empl2 e2) {
		if(e1.getSalary() > e2.getSalary()){
			return 1;
		} else {
			return -1;
		}
	}
}

class Empl2{
	
	private String name;
	private int salary;
	
	public Empl2(String n, int s){
		this.name = n;
		this.salary = s;
	}
	
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public int getSalary() {
		return salary;
	}
	public void setSalary(int salary) {
		this.salary = salary;
	}
	public String toString(){
		return "Name: "+this.name+"-- Salary: "+this.salary;
	}
}

Highest salary emp: Name: John-- Salary: 6000