java-apache http客户端查询，涉及作为多部分发布请求的一部分提交文件

Question

我正在尝试使用最新的Apache HTTP客户端（v4.x）发送多部分POST请求-文档提供的示例代码提供了以下代码示例（经过了部分修改）以发出POST请求-

        FileBody bin = new FileBody(new File(args[0]));
        StringBody comment = new StringBody("A binary file of some kind");
        MultipartEntity reqEntity = new MultipartEntity();
        reqEntity.addPart("bin", bin);
        reqEntity.addPart("comment", comment);
        httppost.setEntity(reqEntity);

我感到困惑的是，如果要添加多个文件，则在代码中

   reqEntity.addPart("bin", bin);

第一个字符串代表什么？ 是作为多部分过帐的一部分发送的文件的名称吗？

Answer 1

多部分表单请求可以包含多个部分，每个部分都有一个名称（类似于常规表单请求）。 给定名称，该名称可在服务器端用于检索特定部分。 RFC 2388中提供了详细信息：

3. Definition of multipart/form-data

       The media-type multipart/form-data follows the rules of all multipart
       MIME data streams as outlined in [RFC 2046].  In forms, there are a
       series of fields to be supplied by the user who fills out the form.
       Each field has a name. Within a given form, the names are unique.

       "multipart/form-data" contains a series of parts. Each part is
       expected to contain a content-disposition header [RFC 2183] where the
       disposition type is "form-data", and where the disposition contains
       an (additional) parameter of "name", where the value of that
       parameter is the original field name in the form. For example, a part
       might contain a header:

            Content-Disposition: form-data; name="user"