Question

我正在关注此guide，以阅读来自Google Pub / Sub中某个主题的电子邮件通知。应用程序启动后，我会看到如下消息到达控制台：

Message arrived! Payload: {"emailAddress":"xxxxx@gmail.com","historyId":712315}

如何将有效负载转换为对象，以便可以检索emailAddress和historyId？

服务激活器如下：

@Bean
  @ServiceActivator(inputChannel = "pubsubInputChannel")
  public MessageHandler messageReceiver() {
    return message -> {
      LOGGER.info("Message arrived! Payload: " + message.getPayload());
      AckReplyConsumer consumer =
          (AckReplyConsumer) message.getHeaders().get(GcpPubSubHeaders.ACKNOWLEDGEMENT);
      consumer.ack();
    };
  }

我要将有效负载转换为的POJO对象是：

public class MessageNotification {

    private String emailAddress;

    private BigInteger historyId;

    public String getEmailAddress() {
        return emailAddress;
    }

    public BigInteger getHistoryId() {
        return historyId;
    }

    public void setHistoryId(BigInteger historyId) {
        this.historyId = historyId;
    }

    public void setEmailAddress(String emailAddress) {
        this.emailAddress = emailAddress;
    }
}

Answer 1

看起来payload是JSON，因此您需要先使用Spring Integration Reference Manual并使用JsonToObjectTransformer，然后再使用该@ServiceActivator：

@Bean
@Transformer(inputChannel = "pubsubInputChannel", outputChannel = "handleChannel")
public JsonToObjectTransformer jsonToObjectTransformer() {
    return new JsonToObjectTransformer(MessageNotification.class);
}

@Bean
@ServiceActivator(inputChannel = "handleChannel")
public MessageHandler messageReceiver() {

  ...

Answer 2

You can extract String message first: String jsonString =message.getPayload.toString();

Now you can convert this json string to:

ObjectMapper objectMapper = new ObjectMapper();
MessageNotification messageNotification = objectMapper.readValue(jsonString , MessageNotification.class);

Spring Integration在服务激活器中将有效负载转换为对象

2 个答案: