Java8 - What is the average salary of each department

Category : Java | Sub Category : Java8 Features | By Prasad Bonam Last updated: 2023-11-13 08:55:37 Viewed : 835

To calculate the average salary of each department in Java 8, you would need an attribute in the Employee class representing the salary. Here is an example:

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import java.util.Arrays;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

public class Employee {
    private String name;
    private String department;
    private double salary;

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

    public String getDepartment() {
        return department;
    }

    public double getSalary() {
        return salary;
    }

    public static void main(String[] args) {
        // Sample data
        List<Employee> employees = Arrays.asList(
                new Employee("John", "HR", 50000),
                new Employee("Jane", "Finance", 60000),
                new Employee("Bob", "IT", 75000),
                new Employee("Alice", "HR", 70000),
                new Employee("Charlie", "IT", 80000)
        );

        // Calculate the average salary for each department using Java 8 streams
        Map<String, Double> averageSalaryByDepartment = employees.stream()
                .collect(Collectors.groupingBy(
                        Employee::getDepartment,
                        Collectors.averagingDouble(Employee::getSalary)
                ));

        // Output the results
        averageSalaryByDepartment.forEach((department, averageSalary) ->
                System.out.println("Average salary in " + department + ": " + averageSalary));
    }
}

Output:

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Average salary in HR: 60000.0
Average salary in Finance: 60000.0
Average salary in IT: 77500.0In this example:

• The Employee class is modified to include a salary attribute.
• Java 8 streams are used with the Collectors.groupingBy collector to group employees by department.
• The Collectors.averagingDouble downstream collector is used to calculate the average salary for each group.
• The results are stored in a Map<String, Double>, where the keys are department names, and the values are the corresponding average salaries.
• The results are then printed to the console.