public class Order {
 private String code;
 private List<String> offers;
 private Map<String, Object> features;
 public static Order.Builder builder(){
  return new Builder();
 }
 //省略getter setter
 public static class Builder {
  private OrderState orderState = new OrderState();
  private static final BeanCopier orderCopier = BeanCopier.create(OrderState.class, Order1.class, false);
  private class OrderState {
   private String code;
   private Map<String, Object> features;
   private List<String> offers;
   //省略getter setter
  }
  public Builder code(String code) {
   orderState.code = code;
   return this;
  }
  public Builder features(Map<String, Object> features) {
   orderState.features = features;
   return this;
  }
  public <T> Builder feature(String key, T obj) {
   if (orderState.features == null) {
    orderState.features = new HashMap<>();
   }
   orderState.features.put(key, obj);
   return this;
  }
  public Builder offers(List<String> offers) {
   orderState.offers = offers;
   return this;
  }
  public Builder offer(String offer) {
   if (orderState.offers == null) {
    orderState.offers = new ArrayList<>();
   }
   orderState.offers.add(offer);
   return this;
  }
  public Order build() {
   Order order = new Order();
   orderCopier.copy(orderState, order1, null);
   orderState = null;
   return order;
  }
 }
}

Order order = Order.builder().code("1235")
  .offer("满100减5")
  .feature("category", "shoe")
  .build();

@Builder
public class Order {
 private String code;
 @Singular
 private List<String> offers;
 @Singular
 private Map<String, Object> features;
}

Order order = Order.builder().code("1234")
   .offer("满100减5")
   .feature("category", "category")
   .build();

public class GenericBuilder<T> {
 private final Supplier<T> instantiator;
 private List<Consumer<T>> instantiatorModifiers = new ArrayList<>();
 private List<Consumer<T>> keyValueModifiers = new ArrayList<>();
 public GenericBuilder(Supplier<T> instantiator) {
  this.instantiator = instantiator;
 }
 public static <T> GenericBuilder<T> of(Supplier<T> instantiator) {
  return new GenericBuilder<T>(instantiator);
 }
 public <U> GenericBuilder<T> with(BiConsumer<T, U> consumer, U value) {
  Consumer<T> c = instance -> consumer.accept(instance, value);
  instantiatorModifiers.add(c);
  return this;
 }
 public <K, V> GenericBuilder<T> with(KeyValueConsumer<T, K, V> consumer, K key, V value) {
  Consumer<T> c = instance -> consumer.accept(instance, key, value);
  keyValueModifiers.add(c);
  return this;
 }
 public T build() {
  T value = instantiator.get();
  instantiatorModifiers.forEach(modifier -> modifier.accept(value));
  keyValueModifiers.forEach(keyValueModifier -> keyValueModifier.accept(value));
  instantiatorModifiers.clear();
  keyValueModifiers.clear();
  return value;
 }
}

 public class Order {
 private String code;
 private List<String> offers;
 private Map<String, Object> features;
 public void addOffer(String offer) {
  offers = Optional.ofNullable(offers)
    .orElseGet(ArrayList::new);
  offers.add(offer);
 }
 public <T> void addFeature(String key, T value) {
  features = Optional.ofNullable(features)
    .orElseGet(HashMap::new);
  features.put(key, value);
 }
 
 //省略getter setter
}

Order order = GenericBuilder.of(Order::new)
     .with(Order::setCode, "123232")
     .with(Order::addOffer, "满100减5")
     .with(Order::addFeature, "category", "shoe")
     .build();