Axon框架中的Axon Saga可以是异步的也可以是同步的,具体取决于你在设计和实现时的需求和偏好。下面给出了两种解决方法的示例代码。
// 定义一个异步的Axon Saga
@Saga
public class MySaga {
@Autowired
private transient CommandGateway commandGateway;
@StartSaga
@SagaEventHandler(associationProperty = "orderId")
public void handle(OrderPlacedEvent event) {
// 处理OrderPlacedEvent并发送异步命令
SomeCommand command = new SomeCommand(event.getOrderId());
commandGateway.send(command, LoggingCallback.INSTANCE);
}
@SagaEventHandler(associationProperty = "orderId")
public void handle(SomeEvent event) {
// 处理SomeEvent并发送异步命令
AnotherCommand command = new AnotherCommand(event.getSomeData());
commandGateway.send(command, LoggingCallback.INSTANCE);
}
@EndSaga
@SagaEventHandler(associationProperty = "orderId")
public void handle(AnotherEvent event) {
// 处理AnotherEvent并结束Saga
}
}
// 定义一个同步的Axon Saga
@Saga
public class MySaga {
@Autowired
private transient CommandGateway commandGateway;
@StartSaga
@SagaEventHandler(associationProperty = "orderId")
public void handle(OrderPlacedEvent event) {
// 处理OrderPlacedEvent并发送同步命令
SomeCommand command = new SomeCommand(event.getOrderId());
commandGateway.sendAndWait(command);
}
@SagaEventHandler(associationProperty = "orderId")
public void handle(SomeEvent event) {
// 处理SomeEvent并发送同步命令
AnotherCommand command = new AnotherCommand(event.getSomeData());
commandGateway.sendAndWait(command);
}
@EndSaga
@SagaEventHandler(associationProperty = "orderId")
public void handle(AnotherEvent event) {
// 处理AnotherEvent并结束Saga
}
}
在上述代码示例中,CommandGateway
用于发送命令,LoggingCallback
用于处理命令发送结果。异步Axon Saga使用send
方法发送命令并提供一个回调函数,而同步Axon Saga使用sendAndWait
方法发送命令并等待返回结果。根据实际需求,选择适合的方式来实现Axon Saga。
上一篇:Axon框架重试逻辑