import java.util.HashMap;  import java.util.Map;  class ServiceContext {  private int tableIndex;  private String customerName;  public ServiceContext(int tableIndex, String customerName) {  this.tableIndex = tableIndex;  this.customerName = customerName;  }  public int getTableIndex() {  return tableIndex;  }  public String getCustomerName() {  return customerName;  }  }  interface Drink {  void provideService(ServiceContext serviceContext);  }  class Coffee implements Drink {  public Coffee() {  System.out.println("Coffee is created.");  }  @Override  public void provideService(ServiceContext serviceContext) {  System.out.println("Coffee is serving for table " + serviceContext.getTableIndex() + " customer " + serviceContext.getCustomerName());  }  }  class Tea implements Drink {  public Tea() {  System.out.println("Drink is created.");  }  @Override  public void provideService(ServiceContext serviceContext) {  System.out.println("Drink is serving for table " + serviceContext.getTableIndex() + " customer " + serviceContext.getCustomerName());  }  }  class Water implements Drink {  public Water() {  System.out.println("Water is created.");  }  @Override  public void provideService(ServiceContext serviceContext) {  System.out.println("Water is serving for table " + serviceContext.getTableIndex() + " customer " + serviceContext.getCustomerName());  }  }  class DrinkFactory {  private Map<String, Drink> drinks = new HashMap<>();  public Drink createDrink(String type) {  Drink drink = drinks.get(type);  if (drink == null) {  // 以下可以考虑抽象工厂模式实现以符合开闭原则，也可以使用反射  if (type.equals("Water")) {  drink = new Water();  } else if (type.equals("Tea")) {  drink = new Tea();  } else if (type.equals("Coffee")) {  drink = new Coffee();  }  drinks.put(type, drink);  }  return drink;  }  }  public class WaiterTest {  public static void main(String[] args) {  String[] types = {"Water", "Tea", "Coffee"};  DrinkFactory drinkFactory = new DrinkFactory();  for (int i = 1; i <= 9; i++) {  Drink drink = drinkFactory.createDrink(types[i % 3]);// Drink 可共享特征 在 DrinkFactory 内部实现享元  ServiceContext serviceContext = new ServiceContext(i, "Sir" + i);// 服务细节为不可共享特征，不能享元  drink.provideService(serviceContext);//外部特征，不可共享特征，保证调用过程不会影响下次调用。
            }  }  }  

Drink is created.
Drink is serving for table 1 customer Sir1
Coffee is created.
Coffee is serving for table 2 customer Sir2
Water is created.
Water is serving for table 3 customer Sir3
Drink is serving for table 4 customer Sir4
Coffee is serving for table 5 customer Sir5
Water is serving for table 6 customer Sir6
Drink is serving for table 7 customer Sir7
Coffee is serving for table 8 customer Sir8
Water is serving for table 9 customer Sir9