-----------------------------
Nama file: Pemesan.java
-----------------------------

public class Pemesan {

    private String nama, alamat, telepon, surel;

    public String getNama() {
        return nama;
    }

    public void setNama(String nama) {
        this.nama = nama;
    }

    public String getAlamat() {
        return alamat;
    }

    public void setAlamat(String alamat) {
        this.alamat = alamat;
    }

    public String getTelepon() {
        return telepon;
    }

    public void setTelepon(String telepon) {
        this.telepon = telepon;
    }

    public String getSurel() {
        return surel;
    }

    public void setSurel(String surel) {
        this.surel = surel;
    }
}

-----------------------------
Nama file: Transaksi.java
-----------------------------

import java.util.ArrayList;

public class Transaksi {

    ArrayList<Pemesan> pemesanList = new ArrayList<>();

    public void simpanPemesan(Pemesan p){
        pemesanList.add(p);
    }

    public void menuJenis(){
        System.out.println("---- JENIS JASA ----");
        System.out.println("1. Cuci Mobil");
        System.out.println("2. Interior");
        System.out.println("3. Detailing");
    }

    public int getBiayaJenis(int j){
        /*
         * cuci mobil 30000
         * salon interior 250000
         * detailing 800000
         */

        if(j == 1){
            return 30000;
        }else if(j == 2){
            return 250000;
        }else if(j == 3){
            return 80000;
        }

        return 0;
    }

    public void menuKaryawan(){
        System.out.println("---- KARYAWAN ----");
        System.out.println("1. Sidik Wibowo");
        System.out.println("2. Thomas Anum");
        System.out.println("3. Wiratno");
        System.out.println("4. Deni Suryana");
    }

    public String pilihKaryawan(int k){

        if(k == 1){
            return "Sidik Wibowo";
        }else if(k == 2){
            return "Thomas Anum";
        }else if(k == 3){
            return "Wiratno";
        }else if(k == 4){
            return "Deni Suryana";
        }

        return null;
    }

}

-----------------------------
Nama file: Main.java
-----------------------------

package latihan05_cuci_mobil;

import java.util.Scanner;

public class Main {
    static Scanner sc = new Scanner(System.in);

    public static void main(String[] args) {
        String nama, alamat, telepon, surel;
        int jenis = 0, karyawan = 0;

        System.out.println("--- DATA PEMESAN ---");
        System.out.print("Nama: \t\t");
        nama = sc.nextLine();
        System.out.print("Alamat: \t");
        alamat = sc.nextLine();
        System.out.print("Telepon: \t");
        telepon = sc.nextLine();
        System.out.print("Surel: \t\t");
        surel = sc.nextLine();

        Pemesan p = new Pemesan();
        p.setNama(nama);
        p.setAlamat(alamat);
        p.setTelepon(telepon);
        p.setSurel(surel);

        Transaksi t = new Transaksi();
        t.simpanPemesan(p);

        // masukkan pilihan
        boolean valid = false;
        t.menuJenis();

        // memastikan user harus input integer
        while (!valid) {
            System.out.print("[ Ketik 1/2/3 ]: ");

            if (sc.hasNextInt()) {
                jenis = sc.nextInt();

                if (jenis > 3) {
                    System.out.println("[ Pilihanmu salah, Coba lagi. ]");
                    valid = false;
                } else {
                    valid = true;
                }
            } else {
                System.out.println("[ Coba lagi! ]");
                sc.next();
                valid = false;
            }
        }

        // menu Karyawan
        t.menuKaryawan();
        valid = false;

        while (!valid) {
            System.out.print("[ Ketik 1/2/3/4 ]: ");

            if (sc.hasNextInt()) {
                karyawan = sc.nextInt();

                if (karyawan > 4) {
                    System.out.println("[ Pilihanmu salah, Coba lagi. ]");
                    valid = false;
                } else {
                    valid = true;
                }
            } else {
                System.out.println("[ Coba lagi! ]");
                sc.next();
                valid = false;
            }
        }

        // Hasil
        System.out.println("----- INFO PEMESANAN -----");
        System.out.println("Nama: \t\t"+ t.pemesanList.get(0).getNama());
        System.out.println("Alamat: \t"+ t.pemesanList.get(0).getAlamat());
        System.out.println("Telepon: \t"+ t.pemesanList.get(0).getTelepon());
        System.out.println("Surel: \t\t"+ t.pemesanList.get(0).getSurel());
        System.out.println("---------- BIAYA ----------");
        System.out.println("Karyawan: \t"+ t.pilihKaryawan(karyawan));

        int jasa = t.getBiayaJenis(jenis);
        double pajak = jasa * 0.025;
        int total = jasa + (int)pajak;

        System.out.println(String.format("By. Jasa: \tRp.%,2d", jasa));
        System.out.println(String.format("Pajak: \t\tRp.%,2d", (int)pajak ));
        System.out.println("---------------------------");
        System.out.println(String.format("Total: \t\tRp.%,2d", total));
    }

}