Employee.java

package com.main;

public class Employee {
	// Atributes of object Employee
	private int id_user = 0;
	private String name = "";
	private String surname = "";

	// Constructor with All atributes
	public Employee(int id_user, String name, String surname) {
		this.id_user = id_user;
		this.name = name;
		this.surname = surname;
	}
	
	//Getters
	public int getId_user() {
		return id_user;
	}

	public String getName() {
		return name;
	}

	public String getSurname() {
		return surname;
	}
	
	//Setters
	public void setId_user(int id_user) {
		this.id_user = id_user;
	}

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

	public void setSurname(String surname) {
		this.surname = surname;
	}

	@Override
	public String toString() {
		return "Employee [id_user=" + id_user + ", name=" + name + ", surname=" + surname + "]";
	}
}

EmployeeBuilder.java

package com.main;

public class EmployeeBuilder {
	// Atributes for the Builder of object Employee
		private int id_user = 0;
		private String name = "";
		private String surname = "";
		
		// Constructor empty
		public EmployeeBuilder() {}
		
		//Employee constructor
		public Employee build() {
			return new Employee(id_user, name, surname);
		}
		
		//Setters EmployeeBuilder with return this
		public EmployeeBuilder setId_user(int id_user) {
			this.id_user = id_user;
			return this;
		}

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

		public EmployeeBuilder setSurname(String surname) {
			this.surname = surname;
			return this;
		}
}

Main.java

package com.main;

public class Main {
	public static void main(String[] args) {
		Employee employee = new EmployeeBuilder()
				.setId_user(1).setName("James")
				.setSurname("Gosling")
				.build();
		System.out.println(employee.toString());
		
		Employee employee2 = new EmployeeBuilder()
				.setId_user(2).setName("Java")
				.setSurname("desde0.com")
				.build();
		System.out.println(employee2.toString());
	}
}