IncompatibleAggregateException（Axon Framework：应用事件后，聚合标识符必须为非空值）

Question

我尝试用Axon配置cqrs和事件源。SeatReseveCreateCommand工作正常。但是SeatReserveUpadateCommand工作不正确。

这是我的SeatReserve集合

@Aggregate
public class SeatReserve {
    @AggregateIdentifier
    private String id;
    private String seatid;
    private Date date;

    @SuppressWarnings("unused")
    private SeatReserve() {
    }

    @CommandHandler
    public SeatReserve(SeatReseveCreateCommand seatReseveCreateCommand) {
        apply(new SeatReseveCreateEvent(seatReseveCreateCommand.getMyid(), seatReseveCreateCommand.getSeatId(),
                seatReseveCreateCommand.getDate()));
    }

    @CommandHandler
    public SeatReserve(SeatReserveUpadateCommand upadateCommand) {
        apply(new SeatReserveUpadateEvent(id, upadateCommand.getSeatId()));
    }

    @EventSourcingHandler
    public void on(SeatReseveCreateEvent seatReseveCreateEvent) {
        this.id = seatReseveCreateEvent.getId();
        this.seatid = seatReseveCreateEvent.getSeatId();
        this.date = seatReseveCreateEvent.getDate();
    }

    @EventSourcingHandler
    public void on(SeatReserveChangeEvent upadateEvent) {
        seatid = upadateEvent.getSeatId();
    }

}

这是我的控制器

@RestController
public class TestController {

    private final CommandGateway commandGateway;

    public TestController(CommandGateway commandGateway) {
        this.commandGateway=commandGateway;
    }

    @PostMapping
    public String fileComplaint(@RequestBody Map<String, String> request) {
        String id = UUID.randomUUID().toString();
        SeatReseveCreateCommand command=new SeatReseveCreateCommand(id,request.get("seatid"),new Date(request.get("date")));
        commandGateway.send(command);
        return id;   
    }
    @PatchMapping
    public String fileComplaintUpdate(@RequestBody Map<String, String> request) {
        SeatReserveUpadateCommand command= new SeatReserveUpadateCommand(request.get("id"),request.get("seatid"));
        commandGateway.send(command);
        return request.get("id");
    }
}

更新导致此错误

2018-01-03 10:44:53.608  WARN 11138 --- [nio-8085-exec-1] o.a.c.gateway.DefaultCommandGateway      : Command 'com.thamira.research.api.bankaccount.SeatReserveUpadateCommand' resulted in org.axonframework.eventsourcing.IncompatibleAggregateException(Aggregate identifier must be non-null after applying an event. Make sure the aggregate identifier is initialized at the latest when handling the creation event.)

我怎么解决这个。

Answer 1

问题是您的update命令被定义为构造函数。该命令应转到已存在的聚合实例。

将命令处理程序更改为：

@CommandHandler
public void handle(SeatReserveUpadateCommand upadateCommand) {...}

应该能解决问题。