Java Program To Sort the Employees Salary in the Organisation in Descending Order

1. Introduction

This tutorial will demonstrate how to create a Java program that sorts employees' salaries in descending order. Sorting salaries this way can help identify top earners and allocate resources accordingly.

Key Points

- Use of a custom Employee class with a salary attribute.

- Application of Java's Stream API for efficient data manipulation.

- Sorting a list of objects based on a salary field in descending order.

2. Program Steps

1. Define the Employee class with necessary attributes, including salary.

2. Create a list of Employee instances.

3. Use Java's Stream API to sort the salaries in descending order.

4. Print the sorted list of employees.

3. Code Program

// File: Employee.java
public class Employee {
    private int id;
    private String name;
    private int age;
    private long salary;
    private String gender;
    private String deptName;
    private String city;
    private int yearOfJoining;

    public Employee(int id, String name, int age, long salary, String gender, String deptName, String city, int yearOfJoining) {
        this.id = id;
        this.name = name;
        this.age = age;
        this.salary = salary;
        this.gender = gender;
        this.deptName = deptName;
        this.city = city;
        this.yearOfJoining = yearOfJoining;
    }

    public long getSalary() {
        return salary;
    }

    @Override
    public String toString() {
        return "Employee{" +
               "id=" + id +
               ", name='" + name + '\'' +
               ", age=" + age +
               ", salary=" + salary +
               ", gender='" + gender + '\'' +
               ", deptName='" + deptName + '\'' +
               ", city='" + city + '\'' +
               ", yearOfJoining=" + yearOfJoining +
               '}';
    }
}

// File: SortSalariesDescending.java
import java.util.*;
import java.util.stream.Collectors;

public class SortSalariesDescending {
    public static void main(String[] args) {
        List<Employee> employees = Arrays.asList(
            new Employee(1, "Aditi", 30, 100000, "F", "HR", "Mumbai", 1995),
            new Employee(2, "Rahul", 25, 130000, "M", "Engineering", "Bangalore", 2000),
            new Employee(3, "Vishal", 34, 110000, "M", "Engineering", "Mumbai", 1998),
            new Employee(4, "Lakshmi", 28, 150000, "F", "HR", "Bangalore", 1992),
            new Employee(5, "Priya", 24, 90000, "F", "Marketing", "Delhi", 2005)
        );

        List<Employee> sortedEmployees = employees.stream()
                                                   .sorted(Comparator.comparingLong(Employee::getSalary).reversed())
                                                   .collect(Collectors.toList());

        sortedEmployees.forEach(System.out::println);
    }
}

Output:

Employee{id=4, name='Lakshmi', age=28, salary=150000, gender='F', deptName='HR', city='Bangalore', yearOfJoining=1992}
Employee{id=2, name='Rahul', age=25, salary=130000, gender='M', deptName='Engineering', city='Bangalore', yearOfJoining=2000}
Employee{id=3, name='Vishal', age=34, salary=110000, gender='M', deptName='Engineering', city='Mumbai', yearOfJoining=1998}
Employee{id=1, name='Aditi', age=30, salary=100000, gender='F', deptName='HR', city='Mumbai', yearOfJoining=1995}
Employee{id=5, name='Priya', age=24, salary=90000, gender='F', deptName='Marketing', city='Delhi', yearOfJoining=2005}

Explanation:

1. The Employee class is defined with necessary fields including salary, which is critical for sorting.

2. A list of Employee objects is created in the SortSalariesDescending main method, and Java Streams are used to sort these objects.

3. The Comparator.comparingLong(Employee::getSalary).reversed() is utilized to sort the salaries in descending order.

4. The sorted list is collected into a new list and printed, showing employees from the highest to the lowest salary.