FindEmployeesWithSameSalary Java 8 Streams

FindEmployeesWithSameSalary.java8

package com.learn.java;

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

public class FindEmployeesWithSameSalary {

    public static void main(String[] args) {

        List<Employee> employees = new ArrayList<>();

        employees.add(new Employee(1, "John" , 1000));
        employees.add(new Employee(1, "Peter" , 2000));
        employees.add(new Employee(1, "Ben" , 3000));
        employees.add(new Employee(1, "Steve" , 2000));
        employees.add(new Employee(1, "Parker" , 1000));

       Map<Integer, List<Employee>> map1 =  employees.stream()
               .collect(Collectors.groupingBy(Employee::getSalary, Collectors.toList()));
       System.out.println("map1 :: "+ map1);

        Map<Integer, List<Employee>> map2 =   employees.stream()
                .collect(Collectors.groupingBy(Employee::getSalary));
        System.out.println("map2 :: "+ map1);

        Map<Integer, Set<String>> map3 =  employees.stream()
                .collect(Collectors.groupingBy
                        (Employee::getSalary, Collectors.mapping
                                (Employee::getName, Collectors.toSet())));
        System.out.println("map3 :: "+ map3);

        map3.forEach((k,v) -> {
            if(v.size()>1) {
                System.out.println("salary :: "+ k + " is same for " + v);
            }
        });

    }
}

-----

OUTPUT

map1 :: {2000=[com.learn.java.Employee@6acbcfc0, com.learn.java.Employee@5f184fc6], 3000=[com.learn.java.Employee@3feba861], 1000=[com.learn.java.Employee@5b480cf9, com.learn.java.Employee@6f496d9f]}
map2 :: {2000=[com.learn.java.Employee@6acbcfc0, com.learn.java.Employee@5f184fc6], 3000=[com.learn.java.Employee@3feba861], 1000=[com.learn.java.Employee@5b480cf9, com.learn.java.Employee@6f496d9f]}
map3 :: {2000=[Steve, Peter], 3000=[Ben], 1000=[Parker, John]}
salary :: 2000 is same for [Steve, Peter]
salary :: 1000 is same for [Parker, John]

---


Employee.java

package com.learn.java;

public class Employee {

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

    private int id;
    private String name;
    private int salary;

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

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

    public int getSalary() {
        return salary;
    }

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