Sorting list of Java objects

In this post we will see how to sort a list of java objects using a property of the object. In this example we will sort the list of employees using their salaries.

Employee:

public class Employee {

 @Override
 public String toString() {
  return "Employee [salary=" + salary + ", department=" + department + ", name=" + name + "]";
 }

 public Employee(int salary, String name, String department) {
  this.salary = salary;
  this.name = name;
  this.department = department;
 }

 public int getSalary() {
  return salary;
 }

 public void setSalary(int salary) {
  this.salary = salary;
 }

 public String getDepartment() {
  return department;
 }

 public void setDepartment(String department) {
  this.department = department;
 }

 public String getName() {
  return name;
 }

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

 int salary;

 String department;

 String name;

}

For sorting create stream of employees and invoke sorted method.

package src;

import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;

public class Sorting {
 
 static List<Employee> employees = new ArrayList<Employee>();
 
 public static List<Employee> sortASC(List<Employee> employees) {
  return employees.stream().sorted((Employee emp1,Employee emp2) -> emp1.getSalary()-emp2.getSalary()).collect(Collectors.toList());
  
 }
 
 public static List<Employee> sortDESC(List<Employee> employees) {
  return employees.stream().sorted((Employee emp1,Employee emp2) -> emp2.getSalary()-emp1.getSalary()).collect(Collectors.toList());
  
 }
 
 public static void main(String args[]) {
  
  Employee emp1 = new Employee(5000,"Mike","Mech");  
  Employee emp2 = new Employee(3000,"Bran","CSE");  
  Employee emp3 = new Employee(6000,"Robert","Electrical");
  
  employees.add(emp1);
  employees.add(emp2);
  employees.add(emp3);
  
  System.out.println("Sort Ascending based on employee Salary....");
  
  sortASC(employees).stream().forEach(System.out::println);
  
  System.out.println("");
  
  System.out.println("Sort Descending based on employee Salary....");
  
  sortDESC(employees).stream().forEach(System.out::println);
  
 }

}

Output:

Sort Ascending based on employee Salary....
Employee [salary=3000, department=CSE, name=Bran]
Employee [salary=5000, department=Mech, name=Mike]
Employee [salary=6000, department=Electrical, name=Robert]

Sort Descending based on employee Salary....
Employee [salary=6000, department=Electrical, name=Robert]
Employee [salary=5000, department=Mech, name=Mike]
Employee [salary=3000, department=CSE, name=Bran]