如何在 ColdFusion 中读取多部分响应 [英] How to Read Multipart Response in ColdFusion

问题描述

我正在向 Web 服务发布 CFHTTP 帖子，该服务返回两部分(多部分)，即 XML 和 PDF.我希望只获得 PDF.我的 cfhttp.filecontent 是 java.io.ByteArrayOutputStream 类型.当我执行 toString() 时，我得到以下信息

I am doing a CFHTTP post to a web service that is returning two parts (multipart), a XML and PDF. I am looking to get only the PDF. My cfhttp.filecontent is a java.io.ByteArrayOutputStream type. When I do a toString() I get the following

第 1 部分

Content-Type: application/xop+xml; type="text/xml"; charset=utf-8
Content-Transfer-Encoding: 8bit

第 2 部分

Content-Type: application/pdf
Content-Transfer-Encoding: binary

我在 cfhttp.fileContent 中得到响应，数据如下所示

I get the response in cfhttp.fileContent and the data looks like the following

--MIME_Boundary
Content-ID: <aa82dfa.N51ec355b.3.15b86044531.59d6>
Content-Type: application/xop+xml; type="text/xml"; charset=utf-8
Content-Transfer-Encoding: 8bit
<?xml version="1.0" encoding="UTF-8"?>
<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">....</soapenv:Envelope>
--MIME_Boundary
Content-Id: <[e-mail]>
Content-Type: application/pdf
Content-Transfer-Encoding: binary

%PDF-1.4
%ÈÁÄ×
<content removed>
25081
%%EOF

--MIME_Boundary--

我尝试删除所有与 PDF 无关的数据，但它仍然不是有效的二进制文件.

I tried to remove all the data that's not related to the PDF but it's still not a valid binary file.

有什么想法吗?

来自评论

当我对 fileContent 执行 cfdump 时，我得到以下信息:

When I do a cfdump on the fileContent I get the following:

Class Name: java.io.ByteArrayOutputStream 
Methods: 
    close() returns void 
    reset() returns void 
    size() returns int 
    toByteArray() returns byte[] 
    toString(java.lang.String) returns java.lang.String 
    toString() returns java.lang.String 
    toString(int) returns java.lang.String 
    write(byte[], int, int) returns void 
    write(int) returns void 
    writeTo(java.io.OutputStream) returns void

当我调用 toByteArray() 时，我得到二进制数据.然后我将数据保存到一个文件中，我可以看到文件的 XML 和 PDF 部分.

When I invoke toByteArray() I get binary data. I then save the data to a file and I see both XML and PDF parts of the file.

推荐答案

解决方案需要进行两项更改:将接受的编码值设置为 gzip、deflate 以及使用 java 处理二进制数据.

The workaround required two changes: a change to set the accepted encoding value to gzip,deflate and to work with binary data using java.

<cfhttpparam type="HEADER" name="Accept-Encoding" value="gzip,deflate">

其次，我需要使用二进制方法来操作响应.

Second I needed to manipulate the response using binary methods.

binResponse = result.fileContent.toByteArray();

接下来我使用了 Ben Nadel 的实用程序，Binary.cfc，它具有我需要的所有二进制操作.我使用方法 binarySlice() 来提取二进制文件的开始和结束部分.切片数据包含我需要的确切格式的二进制文件.它不是 base64 或任何其他类型，它是二进制的.

Next I used a utility from Ben Nadel, Binary.cfc, that has all the binary manipulation I needed. I used the method binarySlice() to extract the start and end part of the binary. The sliced data contains the binary in the exact format that I needed. It was not base64 or any another type, it was binary.

sliced = binNadel.binarySlice( binResponse, <int posistion to start slice>, <int length of binary>));

这个解决方案有效，但它已经成熟，存在潜在问题，例如响应的顺序可能会切换，边界名称可能会改变等.因此这将需要大量的错误处理以确保顺利进行.

This solution works, but it's ripe with potential issues, for example the order of the response could switch, the boundary name could change, etc. So this will require a lot of error handling to ensure smooth sailing.

更新:

接下来我研究了 Leigh 的例子 看看我是否可以简化我的代码.他们建议使用 Java 的 MimeMultipart 类，它支持解析 MTOM 多部分响应.这是最终的工作代码:

Next I looked into Leigh's example to see if I could simplify my code. They suggested using Java's MimeMultipart class which supports parsing an MTOM multipart response. Here is the final working code:

<cfscript>
    // Modify path as needed
    saveToDirec = "c:	emp";

    // Hard coded "boundary" value for DEMO purposes. It MUST match actual value used in cfhttp response
    // Best to use cfhttp.responseHeader.content-Type so [if] the service changes your code won't break.
    contentType = "multipart/related; boundary=MIME_Boundary;";  

    // Load and parse ByteArrayOutputStream returned by CFHTTP
    dataSource = createObject("java", "javax.mail.util.ByteArrayDataSource").init(m_strSoapResponse.fileContent.toByteArray(), javaCast( "string", contentType));
    mimeParts = createObject("java", "javax.mail.internet.MimeMultipart").init(dataSource);

    for (i = 0; i < mimeParts.getCount(); i++) {
        writeOutput("<br>Processing part["& i &"]");
        bp = mimeParts.getBodyPart( javacast("int", i));

        // If this part is a PDF, save it to a file.
        if (!isNull(bp) && bp.isMimeType("application/pdf")) {
            outputFile = createObject("java", "java.io.File").init(saveToDirec &"demo_savedfile_"& i &".pdf");
            bp.saveFile(outputFile);
            writeOutput("<br>Saved: "& outputFile.getAbsolutePath());
        }
    }
</cfscript>

感谢大家的意见！

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