Program: How to search user defined object from a List by using binary search using comparator?

The Collections.binarySearch() method searches the specified list for the specified user defined object using the binary search algorithm. The list must be sorted into ascending order according to the specified comparator (as by the sort(List, Comparator) method), prior to making this call. If it is not sorted, the results are undefined. If the list contains multiple elements equal to the specified object, there is no guarantee which one will be found.

package com.java2novice.collections;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;

public class MyListBinarySearch {

	public static void main(String a[]){
		
		List<Emp> empList = new ArrayList<Emp>();
		empList.add(new Emp(12,"Dinesh",50000));
		empList.add(new Emp(146,"Tom",20000));
		empList.add(new Emp(201,"John",40000));
		empList.add(new Emp(302,"Krish",44500));
		empList.add(new Emp(543,"Abdul",10000));
		
		Emp searchKey = new Emp(201,"John",40000);
		int index = Collections.binarySearch(empList, searchKey, new EmpComp());
		System.out.println("Index of the searched key: "+index);
	}
}

class EmpComp implements Comparator<Emp>{

	public int compare(Emp e1, Emp e2) {
		if(e1.getEmpId() == e2.getEmpId()){
			return 0;
		} else {
			return -1;
		}
	}
}

class Emp {
	
	private int empId;
	private String empName;
	private int empSal;
	
	public Emp(int id, String name, int sal){
		this.empId = id;
		this.empName = name;
		this.empSal = sal;
	}
	
	public int getEmpId() {
		return empId;
	}
	
	public void setEmpId(int empId) {
		this.empId = empId;
	}
	
	public String getEmpName() {
		return empName;
	}
	
	public void setEmpName(String empName) {
		this.empName = empName;
	}
	
	public int getEmpSal() {
		return empSal;
	}
	public void setEmpSal(int empSal) {
		this.empSal = empSal;
	}
	
	public String toString(){
		return empId+" : "+empName+" : "+empSal;
	}
}

Index of the searched key: 2