将XML中的Base64图像写入文件

Question

I have a XML which contains Base64 data, what's the best way to strip it out using a XSLT file? I am using Saxon to reformat the XML and would want to include a filepath in the formatted XML. I looked at a few examples on SO, but can't seem to get it working.

I'm trying to extract the Base64 encoded data and write it to an external file, then programatically write it's location in the XML I output. I may have multiple elements of the same name that contain base64 image data. I have some code below based on some examples I found online and help from experts, but it returns errors, here's a screenshot of the errors I get. http://i.imgur.com/5Np9bNp.png

<?xml version="1.0" encoding="utf-8"?>
<ProcessArea>
<DataArea>
        <Process confirm="Always" acknowledge="Never"/>
        <Image>
<Detail>
                <TypeId>1</TypeId>
                <Description>Description</Description>
                <ImageId>525225</ImageId>
                <New>true</New>
                <PageCount>2</PageCount>
                <ImageData><![CDATA[BASE64String==]]></ImageData>
            </Detail>
        </Image>
    </DataArea>
</ProcessImage>

Below is the XSLT File I am using.

   <!-- Begin XST Style Sheet -->
<xsl:stylesheet 
  version="2.0" 
  xmlns:xsl="http://www.w3.org/1999/XSL/Transform" 
  xmlns:saxon="http://saxon.sf.net/" 
  xmlns:xs="http://www.w3.org/2001/XMLSchema"
  exclude-result-prefixes="saxon" 
  xmlns:fos="java.io.FileOutputStream">

  <!-- Indent in the output -->
  <xsl:output indent="yes"/>

  <!-- Match the root -->
  <xsl:template match="ProcessImage">
    <Import> <!-- Insert our Import Node -->
      <Archive ConnectionID="1" Name="1"> <!-- Define our Application Connection String -->
        <Document pass="True"> <!-- Statically set documents to pass -->
          <xsl:for-each select="Pages/Page"> <!-- Ignore -->
            <DocFile FileLoc="{@FileName}" /> <!-- Ignore -->
          </xsl:for-each>
          <xsl:apply-templates select="DataArea/Image/Detail"/>
        </Document>
      </Archive>
    </Import>
  </xsl:template>

  <xsl:template match="Detail">
    <DocFile FileLoc="C:\SHARE FOLDER\SCANNED FILES\Scan{format-number(position() - 1, '0000')}.tif" /> <!-- Get the Filepath, give it a filename based on its position in the XML -->
    <Fields>
      <xsl:apply-templates select="parent::Image/Header/*[not(self::Count)]"/> <!-- Get Header Data, Ignore Count Node if Present, Apply Templates at bottom of XSL -->
      <xsl:apply-templates select="*"/>
    </Fields>
  </xsl:template>

  <xsl:template match="Header/* | Detail/*[not(self::ImageData)]">  <!-- Match Header OR Detail Child Elements -->
    <Field Name="{name()}" value="{.}" pass="True"/>
  </xsl:template>
<!-- Get Image File -->
  <xsl:template match="Detail/ImageData">
   <xsl:variable name="img" select="concat('file:///c:/test', format-number(count(parent::Detail/preceding-sibling::Detail), '0000'), '.jpg')"/>
  <xsl:variable name="fos" select="fos:new(string($img))"/>
   <xsl:value-of select="
     fos:write($fos,
     saxon:base64Binary-to-octets(xs:base64Binary(.)))"/>
   <xsl:value-of select="fos:close($fos)"/>
</xsl:template>
 </xsl:stylesheet>

Answer 1

It's not clear from your question what output you want to produce.

There are some useful Saxon extension functions for handling base64 data: see

http://www.saxonica.com/documentation/#!functions/saxon

and

http://www.saxonica.com/documentation/#!functions/saxon

For example if you want to write a binary file, first convert the base64 string to an xs:base64Binary value using the xs:base64Binary constructor, then write to the file using the EXPath file:writeBinary() function.

You will need at least Saxon-PE.