mule的Servlet组件将request body放到message的payload中

mule源代码

/*
 * Copyright (c) MuleSoft, Inc.  All rights reserved.  http://www.mulesoft.com
 * The software in this package is published under the terms of the CPAL v1.0
 * license, a copy of which has been included with this distribution in the
 * LICENSE.txt file.
 */
package org.mule.transport.servlet;

import org.mule.DefaultMuleMessage;
import org.mule.api.MuleContext;
import org.mule.api.MuleMessage;
import org.mule.transport.AbstractMuleMessageFactory;
import org.mule.transport.http.HttpConstants;

import java.util.Enumeration;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import org.apache.commons.collections.EnumerationUtils;

public class ServletMuleMessageFactory extends AbstractMuleMessageFactory
{
    ……

    protected Object extractPayloadFromPostRequest(HttpServletRequest request) throws Exception
    {
        /*
         * Servlet Spec v2.5:
         *
         * SRV.3.1.1
         * When Parameters Are Available
         *
         * The following are the conditions that must be met before post form data will
         * be populated to the parameter set:
         *
         * 1. The request is an HTTP or HTTPS request.
         * 2. The HTTP method is POST.
         * 3. The content type is application/x-www-form-urlencoded.
         * 4. The servlet has made an initial call of any of the getParameter family of meth-
         *    ods on the request object.
         *
         * If the conditions are not met and the post form data is not included in the
         * parameter set, the post data must still be available to the servlet via the request
         * object's input stream. If the conditions are met, post form data will no longer be
         * available for reading directly from the request object's input stream.
         *
         * -----------------------------------------------------------------------------------
         *
         * In plain english:if you call getInputStream on a POSTed request before you call one of
         * the getParameter* methods, you'll lose the parameters. So we touch the parameters first
         * and only then we return the input stream that will be the payload of the message.
         */
        request.getParameterNames();

        return request.getInputStream();
    }
    ……
}

 “request.getParameterNames();”这一句代码已经对InpuStream进行了读取，当执行“return request.getInputStream();”时，已经无法从InpuStream中获取到request body了，所以要把 “request.getParameterNames();”这一句代码删除。

重写该factory，然后让Servlet组件调用connector，该connector使用新的factory，如下：

<servlet:connector name="Servlet" doc:name="Servlet">
     <service-overrides messageFactory="com.rakuten.api.coupon.factory.ServletMuleMessageFactory"/>
 </servlet:connector>

Ref：

http://download.oracle.com/otn-pub/jcp/servlet-2.5-mr5-oth-JSpec/servlet-2.5-mr5-spec.pdf?AuthParam=1480926368_0fcec9d71c58792a07c45e3f8f129d65#search=%27servlet+2.5+spec%27

SRV.3.1.1