public final class Employee {
  public static void main(String[] args) {
    // Employee e = new Employee("Lex", 24, 250);
    // e = Employee.setName(e, "Vasili");
    // e = Employee.setAge(e, 12);
    // e = Employee.setSalary(e, 2500);
    // Employee.log(e);
    Stream
      .of(new Employee())
      .map((e, "Vasili") -> Employee::setName)
      .findFirst()
      .get();
  }

  public final String name;
  public final Integer age;
  public final Integer salary;

  public Employee(final String nameArg,
                  final Integer ageArg,
                  final Integer salaryArg) {
    this.name   = nameArg;
    this.age    = ageArg;
    this.salary = salaryArg;
  }

  public static Employee setName(final Employee e, final String n) {
    return new Employee(n, e.age, e.salary);
  }

  public static Employee setAge(final Employee e, final Integer a) {
    return new Employee(e.name, a, e.salary);
  }

  public static Employee setSalary(final Employee e, final Integer s) {
    return new Employee(e.name, e.age, s);
  }

  public static void log(final Employee e) {
    System.out.println("Name: " + e.name + ", " +
                       "age: " + e.age + ", " +
                       "salary: " + e.salary + ".");
  }
}