Spring 集成 DSL 转换器

Question

关于以下问题，我可以在这里得到一些帮助吗：调用转换器将输入 object 转换为 Map Object 并调用处理程序，处理程序缺少之前添加的 header 值。为什么将 payload 转换为 Map object 丢失所有 headers？

//Adding header here setHeader("t", "t");
@ResponseBody
public EmResponse getAuditTrail(@Valid @RequestBody NGAuditTrailEntry auditEntry) {
    LOG.info("Audit Service Called, creating new audit " + auditEntry);
    AuditCreationFlow.CreateAuditGateway auditGateway = applicationContext.getBean(AuditCreationFlow.CreateAuditGateway.class);
    MessageBuilder messageBuilder = MessageBuilder.withPayload(auditEntry).setHeader("t", "t");
    Object response = auditGateway.createAudit(messageBuilder.build());
    EmResponse res = new EmResponse();
    LOG.info("Done with Audit creation. Response " + response);
    return res;
}

//Integration flow starts here
public IntegrationFlow createAuditGatewayFlow() {
    LOG.debug("Entered to spring integration flow to create the Audit entry");
    return IntegrationFlows.from("auditInputChannel")
        .handle(auditObjTransformer, "transformToEjbCompatible")
        .handle(ejbCaller, "callEjb")
        .get();
}

//Transforming payload object to map
@Component
public class AuditObjTransformer {
    private final Logger LOG = LoggerFactory.getLogger(this.getClass());

    @Transformer
    public Object transformToEjbCompatible(NGAuditTrailEntry ngAuditTrailEntry, Map<String, Object> headers) {
        LOG.debug("Transforming the NGAuditTrailEntry To AuditEntry object which is EJB compatible");

        //@TODO - Tranformation code goes here.

        String s = ngAuditTrailEntry.getObjectName();
        Map<String, String> m = new HashMap<>();
        m.put("x", s);
        return m;
    }

//Here in this handler, not getting headers what I added in the rest service above.
public class EJBCaller {
    private final Logger LOG = LoggerFactory.getLogger(this.getClass());

    public Object callEjb(Object payload, Map<String, Object> headers) throws EJBResponseException {
        LOG.debug("Calling Audit EJB to crated Audit entry.");

        //@TODO EJB calling code goese here.

        LOG.debug("Returned from EJB after creating Audit entry. Returned value" + payload);
        return payload;
    }

如果变换不是映射，则 header 秒内没有问题。

谢谢，湿婆

Answer 1

 callEjb(Object payload, Map<String, Object> headers)

如果有效负载是 Map，您在 payload 和 headers 方法参数中同时拥有该有效负载。

要使其正常工作并准确地将 headers 传递给 Map 参数，您应该在其上使用 @Headers 注释：

 * Annotation which indicates that a method parameter should be bound to the headers of a
 * message. The annotated parameter must be assignable to {@link java.util.Map} with
 * String keys and Object values.

Spring 集成 DSL 转换器

Spring Integration DSL transformer

spring-integration

spring-integration-dsl