COMPARATOR::: Sort Employee Object using employee id

package comparator.Emp;
//When we are not allowed to change Class Employee code (i.e we can't implement Comparable)
//We use comparator Interface.
public class Employee
{
int empid;
String name;
int deptid;
public Employee(int empid, String name, int deptid)
{
super();
this.empid = empid;
this.name = name;
this.deptid = deptid;
}
/*@Override
public String toString() {
return "Empid=" + empid + ", Name=" + name + ", Deptid=" + deptid;
}*/


}

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package comparator.Emp;

import java.util.*;

//Sort the Employeee Class using empid -- Use Comparator

public class Emp_Runner {

public static void main(String[] args) 

{

Employee emp1  = new Employee(111,"Amit",549);

Employee emp2  = new Employee(674,"Dinesh",549);

Employee emp3  = new Employee(352,"Manohar",667);

Employee emp4  = new Employee(642,"Dilip",889);

Employee emp5  = new Employee(133,"Govind",667);

 

List list = new ArrayList();

list.add(emp1);

list.add(emp2);

list.add(emp3);

list.add(emp4);

list.add(emp5);

 

Comparator comp = new Emp_Comp(); //Comparator is Interface so we can't instanciate it.

Collections.sort(list,new Emp_Comp());  //call to compare() .... from here

 

Iterator itr = list.iterator();

while(itr.hasNext())

{

Employee emp = (Employee) itr.next();

System.out.println("Empid=" + emp.empid + ", Name=" + emp.name + ", Deptid=" + emp.deptid);

 

}

 

 

}

}

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package comparator.Emp;

import java.util.Comparator;

public class Emp_Comp implements Comparator<Employee>

{

@Override

public int compare(Employee e1, Employee e2) 

{

if(e1.empid > e2.empid)

{

return 1;

}

else return 

-1;

}

}

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