序言中不允许内容，但序言在运行时可以吗？ Groovy，Jenkins，Java，管道，XML [重复]

Posted 2023-02-26

【中文标题】序言中不允许内容，但序言在运行时可以吗？ Groovy，Jenkins，Java，管道，XML [重复]

【英文标题】：Content is not allowed in prolog, but prolog is fine at run-time? Groovy, Jenkins, Java, Pipeline, XML [duplicate]

【发布时间】：2019-10-20 18:08:54

【问题描述】：

我正在尝试从 Jenkins 管道中的 XML 文件中获取版本号。但是，我不断收到以下错误消息

"org.xml.sax.SAXParseException; lineNumber: 1; columnNumber: 1; 序言中不允许有内容。”

我已尝试使用不同的编码进行编码。 （UTF-8-BOM）。我还尝试指定在将 XML 文件读入变量以进行解析时使用的编码。我还尝试重新编码变量并将其放入另一个字符串中。

这是我的 XML 文件。

<?xml version="1.0" encoding="UTF-8"?>
<!--
This is a nuspec. It mostly adheres to https://docs.nuget.org/create/Nuspec-Reference. Chocolatey uses a special version of NuGet.Core that allows us to do more than was initially possible. As such there are certain things to be aware of:
* the package xmlns schema url may cause issues with nuget.exe
* Any of the following elements can ONLY be used by choco tools - projectSourceUrl, docsUrl, mailingListUrl, bugTrackerUrl, packageSourceUrl, provides, conflicts, replaces 
* nuget.exe can still install packages with those elements but they are ignored. Any authoring tools or commands will error on those elements 
-->
<!-- Do not remove this test for UTF-8: if “O” doesn’t appear as greek uppercase omega letter enclosed in quotation marks, you should use an editor that supports UTF-8, not this one. -->
<package xmlns="http://schemas.microsoft.com/packaging/2015/06/nuspec.xsd">
  <metadata>
    <!-- == PACKAGE SPECIFIC SECTION == -->
    <id>Test-Package</id>
    <version>18.5.0</version>
    <owners>Conor</owners>
    <!-- ============================== -->
    <!-- == SOFTWARE SPECIFIC SECTION == -->
    <title>test (Install)</title>
    <authors>Conor</authors>
    <tags>test package test-package</tags>
    <summary>test package Jenkins</summary>
    <description>Test package for CI.</description>
    <!-- =============================== -->      
    <!--<dependencies>
    </dependencies>-->
  </metadata>
</package>

这是我用来获取 XML 文件和访问版本的代码。

strNuspec = "test.nuspec"  
encoding = "UTF-8"  

//We need to read the file and store the output within a variable we will then process that variable using the XMLParser.  

echo 'Reading nuspec into string' 
def xml = readFile file: "$strNuspec", encoding: "$encoding"
println xml  


//Attempting to flush the buffer due to having issues with prolog.
println ""  


//YOU CAN NOT PROCESS THE XML file directly!!! This is why we had to read the file into a string then process the string.  

echo 'Extracting and printing the version number'   
//Parsing the document with XML SLurper.  
def xmlPackage = new XmlSlurper().parseText(xml)  

//We start traversing the document from xmlPackage We can't use 'package' because it is a reserved keyword (Might give us complications).  

def getVersion = xmlPackage.metadata.version

//We have the instance of the version node, we want the text inside that node so we call the text() method.  

def version = getVersion.text()  
//Print the version so that we know we were successful.  

println version

在运行时使用 XML 值。 （使用 println 输出）

<?xml version="1.0" encoding="UTF-8"?>
<!--
This is a nuspec. It mostly adheres to https://docs.nuget.org/create/Nuspec-Reference. Chocolatey uses a special version of NuGet.Core that allows us to do more than was initially possible. As such there are certain things to be aware of:
* the package xmlns schema url may cause issues with nuget.exe
* Any of the following elements can ONLY be used by choco tools - projectSourceUrl, docsUrl, mailingListUrl, bugTrackerUrl, packageSourceUrl, provides, conflicts, replaces 
* nuget.exe can still install packages with those elements but they are ignored. Any authoring tools or commands will error on those elements 
-->
<!-- Do not remove this test for UTF-8: if “O” doesn’t appear as greek uppercase omega letter enclosed in quotation marks, you should use an editor that supports UTF-8, not this one. -->
<package xmlns="http://schemas.microsoft.com/packaging/2015/06/nuspec.xsd">
  <metadata>
    <!-- == PACKAGE SPECIFIC SECTION == -->
    <id>Test-Package</id>
    <version>18.5.0</version>
    <owners>Conor</owners>
    <!-- ============================== -->
    <!-- == SOFTWARE SPECIFIC SECTION == -->
    <title>test (Install)</title>
    <authors>Conor</authors>
    <tags>test package test-package</tags>
    <summary>test package Jenkins</summary>
    <description>Test package for CI.</description>
    <!-- =============================== -->      
    <!--<dependencies>
    </dependencies>-->
  </metadata>
</package>

我希望获得版本并将其输出到屏幕上。

【问题讨论】：

我相信你在 xml 中有一些前缀，比如 BOM。解析器不允许这样做。

这是我最初的想法，但是在指定编码后前缀丢失了？

【参考方案1】：

XmlSlurper 不可序列化，因此 Jenkins 不能很好地应对。但是，如果您的 XML 结构足够简单（即标签在同一行打开和关闭，并且每个标签都有一个唯一的名称）并且您只需要版本文本，您可以使用一个小的正则表达式：

def xml = readFile file: "$strNuspec", encoding: "$encoding"

def getXmlInnerText =  attribute ->
  def matcher = xml =~ "<$attribute>(.+)</$attribute>"
  matcher ? matcher[0][1] : null


def version = getXmlInnerText("version")
println version

【讨论】：

我需要使用 XML 解析器来操作未来的版本。不过还是谢谢你。