从入站网关检索多个查询参数

Question

我有一个应该为查询参数提供服务并返回响应的配置。这是我的配置。不幸的是，Spring无法创建。

<int-http:inbound-gateway request-channel="inChannel"
        reply-channel="outChannel" supported-methods="GET" 
        path="/ticket">

        <int-http:request-mapping consumes="text/plain" params="param1,param2,param3"
            produces="text/plain" />
</int-http:inbound-gateway>

<int:service-activator ref="ticketIssuingService" method="processTicket"
        input-channel="inChannel" output-channel="outChannel"/>

@MessageEndpoint
public class TicketIssuingService {



    public String processTicket(??? payload){
        System.out.println("Query Paramter String is "+payload);
        return null;
    }
}

m3=duration

如何检索参数以便切换到processTicket方法？Spring抱怨说没有找到合适的方法。processTicket方法的参数应该是什么？请帮帮忙

Answer 1

对于没有GET的payload-expression方法，用于inChannel的Message<?>的payload恰好是以下对象：

MultiValueMap<String, String> requestParams = this.convertParameterMap(servletRequest.getParameterMap());

...

        if (payload == null) {
            if (requestBody != null) {
                payload = requestBody;
            }
            else {
                payload = requestParams;
            }
        }

因此，这应该是关于payload服务方法中的processTicket类型的问题的答案。

请注意，您可以通过payload-expression定制该payload-expression，并使用一些内置的SpEL EvaluationContext 变量，例如：

#requestParams - the MultiValueMap from the ServletRequest parameterMap.
#pathVariables - the Map from URI Template placeholders and their values;
#matrixVariables - the Map of MultiValueMap according to Spring MVC Specification. Note, #matrixVariables require Spring MVC 3.2 or higher;
#requestAttributes - the org.springframework.web.context.request.RequestAttributes associated with the current Request;
#requestHeaders - the org.springframework.http.HttpHeaders object from the current Request;
#cookies - the Map<String, Cookie> of javax.servlet.http.Cookie s from the current Request. 

有些示例是这样获得queryString的

payload-expression="T(org.springframework.web.context.request.RequestContextHolder).requestAttributes.request.queryString"