无法使用Repository.load()为Integer AggregateIdentifier加载聚合

我一直在尝试使用存储库类的加载方法加载聚合，但没有成功。我知道load((方法需要一个字符串参数，但我的聚合标识符是integer。我已经尝试转换为字符串，但无法加载聚合。我一直都是空的。我的代码显示在下面

@Autowired
private Repository<Product> repository;
@CommandHandler
public Order(CreateOrderCommand cmd){
try{
//This line throws an error
Product product = (Product) repository.load(Integer.toString(cmd.getProductId()));
}
catch (Exception ex){
System.out.println("Oops! Error Occured: " + ex.getMessage());
}
apply(
new OrderCreatedEvent(
cmd.getOrderId(), cmd.getPrice(), cmd.getNumber(), cmd.getProductId()
)
);
}

我正在提供更多更新：我只是想在下新订单时更新产品库存。因此，我所做的是，在创建新订单的CommandHandler中，我只需找到Product聚合并调用它的UpdateStock方法，这是一个命令处理程序。有什么我真的不明白吗？

这些文件如下：产品汇总：

@Aggregate
public class Product {
@AggregateIdentifier
private String id;
private Double price;
private Integer stock;
private String description;
public Product() {
}
@CommandHandler
public Product(AddProductCommand cmd){
apply( new ProductAddedEvent(
cmd.getId(),
cmd.getPrice(),
cmd.getStock(),
cmd.getDescription()
)
);
}
@CommandHandler
public void updateStock (UpdateStockCommand cmd){
if(this.stock >= cmd.getStock()){
apply(new StockUpdatedEvent(cmd.getId(), cmd.getStock()));
}
else {
throw new RuntimeException("Out of Stock!");
}
}
@EventSourcingHandler
public void on(StockUpdatedEvent evt){
id = evt.getId();
stock = stock - evt.getStock();
}
@EventSourcingHandler
public void on(ProductAddedEvent evt){
id = evt.getId();
price = evt.getPrice();
stock = evt.getStock();
description = evt.getDescription();
}
}

订单汇总：

@Aggregate
public class Order {
@AggregateIdentifier
private String  orderId;
private Double price;
private Integer number;
private String productId;
//Repository provides an abstraction for storage of Aggregates
@Autowired
private Repository<Product> repository;
@CommandHandler
public Order(CreateOrderCommand cmd){
try{
//This line throws an error
Product product = (Product) repository.load(cmd.getProductId());
}
catch (Exception ex){
System.out.println("Oops! Error Occured: " + ex.getMessage());
}
apply(
new OrderCreatedEvent(
cmd.getOrderId(), cmd.getPrice(), cmd.getNumber(), cmd.getProductId()
)
);
}
@EventSourcingHandler
public void on(OrderCreatedEvent evt){
orderId = evt.getOrderId();
price = evt.getPrice();
number = evt.getNumber();
productId = evt.getProductId();
}
}