Company Roster

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Map;
import java.util.OptionalDouble;


/**
 *
 * @author chobi
 */
public class Employee {




    private String name;
    private double salary;
    private String position;
    private String department;
    private String email;
    private int age;

    public Employee(Builder builder) {
        this.name = builder.name;
        this.salary = builder.salary;
        this.position = builder.position;
        this.department = builder.department;
        this.email = builder.email;
        this.age = builder.age;
    }



     public static class Builder {
       private String name;
       private double salary;
       private String position;
       private String department;
       private String email = "n/a";
       private int age = -1;

       private Builder name (String name){
           this.name = name;
           return this;
       }

       private Builder salary (Double salary){
           this.salary = salary;
           return this;
       }

       private Builder position (String position){
           this.position = position;
           return this;
       }

       private Builder department (String department){
           this.department = department;
           return this;
       }

       private Builder email (String email){
           this.email = email;
           return this;
       }

       private Builder age (Integer age){
           this.age = age;
           return this;
       }

       public Employee build() {
           return new Employee(this);
       }
     }

    public static void main(String[] args) throws Exception {
        InputStreamReader isr = new InputStreamReader(System.in);
        BufferedReader reader = new BufferedReader(isr);

        int count = Integer.parseInt(reader.readLine());

        Map<String, ArrayList<Employee>> employeeList = new HashMap<>();
        Map<String, ArrayList<Double>> averageDepartmentSalary = new HashMap<>();

        for (int i = 0; i < count; i++) {
            String[] input = reader.readLine().split("\\s+");
            addEmployee(input, employeeList);
            if (!averageDepartmentSalary.containsKey(input[3])) {
            averageDepartmentSalary.put(input[3], new ArrayList<>());
            averageDepartmentSalary.get(input[3]).add(Double.parseDouble(input[1]));

        }else{
            averageDepartmentSalary.get(input[3]).add(Double.parseDouble(input[1]));
            }


        }


        String highestAverageSalary = averageDepartmentSalary.entrySet().stream()
                .max((entry1, entry2) -> averageValue(entry1.getValue()) > averageValue(entry2.getValue()) ? 1 : -1).get().getKey();



        for (Map.Entry <String, ArrayList<Employee>> arg : employeeList.entrySet()) {
            if (arg.getKey().equals(highestAverageSalary)) {
                System.out.printf("Highest Average Salary: %s%n", arg.getKey());
                 arg.getValue().
                         stream().
                         sorted((p1, p2) ->Double.compare(p2.salary, p1.salary)).
                         forEach(employee -> System.out.printf("%s %.2f %s %d%n",
                                                                 employee.name,
                                                                 employee.salary,
                                                                 employee.email,
                                                                 employee.age));


            }


        }



    }

    private static void addEmployee(String[] input, Map<String, ArrayList<Employee>> employeeList) {
        int numStats = input.length;
        if (!employeeList.containsKey(input[3])) {
            employeeList.put(input[3], new ArrayList<>());
        }
        switch(numStats){

            case 4: employeeList.get(input[3]).add(new Employee.Builder().
                    name(input[0]).
                    salary(Double.parseDouble(input[1])).
                    position(input[2]).
                    department(input[3]).
                    build());

            break;

            case 5:if (input[4].contains("@")) {
                 employeeList.get(input[3]).add(new Employee.Builder().
                    name(input[0]).
                    salary(Double.parseDouble(input[1])).
                    position(input[2]).
                    department(input[3]).
                    email(input[4]).
                    build());
                }else{
                employeeList.get(input[3]).add(new Employee.Builder().
                    name(input[0]).
                    salary(Double.parseDouble(input[1])).
                    position(input[2]).
                    department(input[3]).
                    age(Integer.parseInt(input[4])).
                    build());
            }

            break;

            case 6:
                 employeeList.get(input[3]).add(new Employee.Builder().
                    name(input[0]).
                    salary(Double.parseDouble(input[1])).
                    position(input[2]).
                    department(input[3]).
                    email(input[4]).
                    age(Integer.parseInt(input[5])).
                    build());
            break;
        }
    }

    private static Double averageValue(ArrayList<Double> value) {

        return value.stream().mapToDouble(i -> i).average().orElse(0);
    }
}