如何在Mule3.5.2中链接RESTful web服务调用

<http:request-config name="RESTful_Request_Config" host="api.example.com" port="80" basePath="/api" doc:name="HTTP Request Configuration">
    <http:request-connection host="api.example.com" port="80" />
</http:request-config>

<http:request config-ref="RESTful_Request_Config" path="/users/{userId}" method="GET" doc:name="HTTP">
    <http:request-builder>
        <http:uri-param paramName="userId" value="#[flowVars.userId]" />
    </http:request-builder>
</http:request>

<json:json-to-object-transformer returnClass="java.util.HashMap" doc:name="JSON to Object" />