更新：问题似乎是我使用了两次的id，或者换句话说，是我想要用于productinventory实体的产品实体的id。一旦我为productinventory实体生成了一个新的id，它似乎就可以正常工作了。但我希望两者的id相同，因为它们是同一个产品。
我有两项服务：
productmanagementservice（使用产品详细信息保存产品实体）
1.）为了保存产品实体，我实现了一个eventhandler，它侦听productcreatedevent并将产品保存到mysql数据库。
productinventoryservice（将具有产品库存量的productinventory实体保存到productmanagementservice中定义的某个productid）
2.）为了保存productinventory实体，我还实现了一个eventhandler，它侦听productinventorycreatedevent并将产品保存到mysql数据库。
我想做的是：
在productmanagementservice中创建新产品时，我希望在productinventoryservice中直接创建productinventory实体，并将其保存到我的msql表中。新产品库存实体应具有与产品实体相同的id。
为了实现这一点，我创建了一个saga，该saga将列出productcreatedevent并发送一个新的createproductinventorycommand。一旦createproductinventorycommand触发productinventorycreatedevent，eventhandler（如2.）中所述）就会捕获它。但事实并非如此。
thta唯一保存的是产品实体，因此总结起来：
1.）有效，2.）无效。会创建productinventory聚合，但不会保存它，因为不会触发连接到eventhandler的保存进程。
我也遇到了一个例外，应用程序没有崩溃： Command 'com.myApplication.apicore.command.CreateProductInventoryCommand' resulted in org.axonframework.commandhandling.CommandExecutionException(OUT_OF_RANGE: [AXONIQ-2000] Invalid sequence number 0 for aggregate 3cd71e21-3720-403b-9182-130d61760117, expected 1) 我的传奇：

@Saga
@ProcessingGroup("ProductCreationSaga")
public class ProductCreationSaga {

    @Autowired
    private transient CommandGateway commandGateway;

    @StartSaga
    @SagaEventHandler(associationProperty = "productId")
    public void handle(ProductCreatedEvent event) {
        System.out.println("ProductCreationSaga, SagaEventHandler, ProductCreatedEvent");

        String productInventoryId = event.productId;
        SagaLifecycle.associateWith("productInventoryId", productInventoryId);
    //takes ID from product entity and sets all 3 stock attributes to zero
        commandGateway.send(new CreateProductInventoryCommand(productInventoryId, 0, 0, 0));
    }

    @SagaEventHandler(associationProperty = "productInventoryId")
    public void handle(ProductInventoryCreatedEvent event) {
        System.out.println("ProductCreationSaga, SagaEventHandler, ProductInventoryCreatedEvent");

        SagaLifecycle.end();
    }

}

按预期工作并保存产品实体的eventhandler：

@Component
public class ProductPersistenceService {

    @Autowired
    private ProductEntityRepository productRepository;

    //works as intended
    @EventHandler
    void on(ProductCreatedEvent event) {
        System.out.println("ProductPersistenceService, EventHandler, ProductCreatedEvent");
        ProductEntity entity = new ProductEntity(event.productId, event.productName, event.productDescription, event.productPrice);
        productRepository.save(entity);

    }

    @EventHandler
    void on(ProductNameChangedEvent event) {
        System.out.println("ProductPersistenceService, EventHandler, ProductNameChangedEvent");
        ProductEntity existingEntity = productRepository.findById(event.productId).get();

        ProductEntity entity = new ProductEntity(event.productId, event.productName, existingEntity.getProductDescription(), existingEntity.getProductPrice());
        productRepository.save(entity);

    }
}

应保存productinventory实体但不保存的eventhandler：

@Component
public class ProductInventoryPersistenceService {

    @Autowired
    private ProductInventoryEntityRepository productInventoryRepository;

    //doesn't work
    @EventHandler
    void on(ProductInventoryCreatedEvent event) {
        System.out.println("ProductInventoryPersistenceService, EventHandler, ProductInventoryCreatedEvent");
        ProductInventoryEntity entity = new ProductInventoryEntity(event.productInventoryId, event.physicalStock, event.reservedStock, event.availableStock);
        System.out.println(entity.toString());

        productInventoryRepository.save(entity);

    }

}

产品聚合：

@Aggregate
public class Product {

    @AggregateIdentifier
    private String productId;

    private String productName;

    private String productDescription;

    private double productPrice;

    public Product() {
    }

    @CommandHandler
    public Product(CreateProductCommand command) {
        System.out.println("Product, CommandHandler, CreateProductCommand");
        AggregateLifecycle.apply(new ProductCreatedEvent(command.productId, command.productName, command.productDescription, command.productPrice));
    }

    @EventSourcingHandler
    protected void on(ProductCreatedEvent event) {
        System.out.println("Product, EventSourcingHandler, ProductCreatedEvent");

        this.productId = event.productId;
        this.productName = event.productName;
        this.productDescription = event.productDescription;
        this.productPrice = event.productPrice;
    }

}

产品库存合计：

@Aggregate
public class ProductInventory {

    @AggregateIdentifier
    private String productInventoryId;

    private int physicalStock;

    private int reservedStock;

    private int availableStock;

    public ProductInventory() {
    }

    @CommandHandler
    public ProductInventory(CreateProductInventoryCommand command) {
        System.out.println("ProductInventory, CommandHandler, CreateProductInventoryCommand");
        AggregateLifecycle.apply(new ProductInventoryCreatedEvent(command.productInventoryId, command.physicalStock, command.reservedStock, command.availableStock));
    }

    @EventSourcingHandler
    protected void on(ProductInventoryCreatedEvent event) {
        System.out.println("ProductInventory, EventSourcingHandler, ProductInventoryCreatedEvent");

        this.productInventoryId = event.productInventoryId;
        this.physicalStock = event.physicalStock;
        this.reservedStock = event.reservedStock;
        this.availableStock = event.availableStock;
    }

}