基于JAVA中Jersey处理Http协议中的Multipart的详解

     那么Http协议中的Multipart是个什么东东？下面是摘抄http协议1.1的一段话：
在multipart entity(多部分实体)的例子中，一个或多个不同的数据集合并在一个单一的body(体)中，一个"multipart"（多部分）类型 field的（域）必须出现在实体的header(头域)。body（体）必须包括一个或多个body part（体部分)，每一个位于boundary（边界）定界符线之前，最后一个则跟着一个结束边界定界符线。在它的边界定界符线后，每一个体部分由头域、空行、体组成。
     上面的描述写的有点拗口，简单的理解可以为：一个post的请求，可以根据一定规范去定义多个部分；

     下面用移动网状网协议（其实就是一个请求中包括2个独立的xml内容，一个head的xml，一个body的xml）去举例说明如何利用Jersey处理Multipart，主要代码如下（开始的时候server端接收的代码死活不知道如何写也没查到别人怎么写的，后来一生气，反编译jersey-multipart-1.0.3.1.jar包的代码看了下，才明白）：

private static WebResource webResource = client.resource("http://xxx.xx.xx:xxx");

public static final String HeadFieldName = "xmlhead";
public static final String BodyFieldName = "xmlbody";

 
// Client发送代码
public static String post(String head, String body) throws BusinessException {
        FormDataMultiPart multiPart = new FormDataMultiPart();
        multiPart.field(RequestField.HeadFieldName, head, MediaType.MULTIPART_FORM_DATA_TYPE);
        multiPart.field(RequestField.BodyFieldName, body, MediaType.MULTIPART_FORM_DATA_TYPE);
        return webResource.type("multipart/form-data").post(String.class, multiPart);
    }

// Server端接收代码
          @POST
    @Produces({MediaType.APPLICATION_XML, MediaType.MULTIPART_FORM_DATA})
    @Consumes({MediaType.APPLICATION_XML, MediaType.MULTIPART_FORM_DATA})   
    public String service(FormDataMultiPart multiPart) throws Exception{
        if(multiPart == null){
            if(_logger.isErrorEnabled()){
                _logger.error("the request FormDataMultiPart is null");
            }

            throw new Exception("the request FormDataMultiPart is null");
        }

        List<RequestField> requestFields = new ArrayList<RequestField>();
        for(BodyPart bodyPart : multiPart.getBodyParts()){
            String fieldName = ((FormDataBodyPart)bodyPart).getName().trim();
            if(fieldName.equalsIgnoreCase(RequestField.HeadFieldName)){
                requestFields.add(new RequestField(fieldName, bodyPart.getEntityAs(String.class)));
            }
            else if(fieldName.equalsIgnoreCase(RequestField.BodyFieldName)){
                requestFields.add(new RequestField(fieldName, bodyPart.getEntityAs(String.class)));
            }
            else{
                if(_logger.isWarnEnabled()){
                    _logger.warn("invalid fieldName:" + fieldName + ",originXml:" + bodyPart.getEntityAs(String.class));
                }
            }
        }

        .....
    }

用工具抓包的实际post报文：

POST /ba/resources/bossServer HTTP/1.1
Content-Type: multipart/form-data;boundary=Boundary_1_30911772_1367997277472
MIME-Version: 1.0
User-Agent: Java/1.6.0_10-rc2
Host: 192.168.245.18:8082
Accept: text/html, image/gif, image/jpeg, *; q=.2, */*; q=.2
Connection: keep-alive
Content-Length: 1600
--Boundary_1_30911772_1367997277472
Content-Disposition: form-data;name="xmlhead"
Content-Type: multipart/form-data

<?xml version="1.0" encoding="UTF-8"?>
<InterBOSS>
    <Version>0100</Version>
    <TestFlag>0</TestFlag>
    <BIPType>
        <BIPCode>BIP2B543</BIPCode>
        <ActivityCode>T2001543</ActivityCode>
        <ActionCode>0</ActionCode>
    </BIPType>
    <RoutingInfo>
        <OrigDomain>IMPS</OrigDomain>
        <RouteType>01</RouteType>
        <Routing>
            <HomeDomain>BOSS</HomeDomain>
            <RouteValue>13810494631</RouteValue>
        </Routing>
    </RoutingInfo>
    <TransInfo>
        <SessionID>2013050815143783928824</SessionID>
        <TransIDO>2013050815143783928824</TransIDO>
        <TransIDOTime>20130508151437</TransIDOTime>
    </TransInfo>
</InterBOSS>
--Boundary_1_30911772_1367997277472
Content-Disposition: form-data;name="xmlbody"
Content-Type: multipart/form-data

<?xml version="1.0" encoding="UTF-8"?>
<InterBOSS>
<SvcCont><![CDATA[<subscribeServiceReq>
    <msgTransactionID>210001BIP2B543130508151437477294</msgTransactionID>
    <subscribeServInfo>
        <oprTime>20130508151436</oprTime>
        <actionID>06</actionID>
        <effTime>20130508151437</effTime>
        <expireTime>30000101000000</expireTime>
        <feeUser_ID>13810494631</feeUser_ID>
        <destUser_ID>13810494631</destUser_ID>
        <actionReasonID>1</actionReasonID>
        <servType>210001</servType>
        <subServType>FXCJHY</subServType>
        <SPID>901508</SPID>
        <SPServID>FXCJHY</SPServID>
        <accessMode>01</accessMode>
        <feeType>2</feeType>
    </subscribeServInfo>
</subscribeServiceReq>]]></SvcCont>
</InterBOSS>
--Boundary_1_30911772_1367997277472--