vbscript - 使用经典 ASP (VBscript) 解析 XML 时出现问题

Question

我有以下代码，它曾经工作得很好，但现在由于某些原因却不能了。

我正在阅读的 XML 位于:https://forex.boi.org.il/currency.xml

以下代码应解析 XMl，然后保存 USD/ILS 汇率。正如我所说，它不再是了，我不知道出了什么问题。

forexURL = "https://forex.boi.org.il/currency.xml"

getUSDRate = 0 
MyRate = 0 

Set xmlObj = Server.CreateObject("MSXML2.FreeThreadedDOMDocument")
xmlObj.async = False
xmlObj.setProperty "ServerHTTPRequest", True
xmlObj.Load(forexURL)
Set xmlList = xmlObj.getElementsByTagName("CURRENCY")
Set xmlObj = Nothing
x = 1
For Each xmlItem In xmlList

    response.write "<p>" &  xmlItem.childNodes(0).text
    response.write "<p>" &    xmlItem.childNodes(1).text
    response.write "<p>" &   xmlItem.childNodes(2).text
    response.write "<p>" &   xmlItem.childNodes(3).text
    response.write "<p>" &   xmlItem.childNodes(4).text
    response.write "<p>" &   xmlItem.childNodes(5).text
    response.write "<p>___________________<br />" & x & "</p>"

    if xmlItem.childNodes(2).text = "USD" then 
        MyRate = xmlItem.childNodes(4).text
        exit for
    end if 

    x = x +1

Next
Set xmlList = Nothing

Answer 1

我怀疑(提前猜测)服务器端处理 SSL 的方式发生变化是导致您遇到麻烦的原因。也许他们禁用了旧的、更不安全的密码来应对最近的 SSL 错误。

就像 @John 注释一样 - 当您从 MSXML2.FreeThreadedDOMDocument (加载版本 MSXML2 版本 3)更改为显式加载更现代的版本 6 (MSXML2.FreeThreadedDOMDocument.6.0) >)则文档下载成功。

话虽这么说，我对您的代码做了一些更改，主要是为了更具可读性，并在文档加载由于某种原因失败时使其明显失败。

注意

• XPath 的使用
• 辅助函数 GetText() 代替盲目索引子节点
• parseError 检查以使 LoadXmlDocument 非静默失败

.

Option Explicit

Dim usdRate, x, currencies, curr

Set currencies = LoadXmlDocument("https://forex.boi.org.il/currency.xml")
usdRate = GetText(currencies, "//CURRENCY[CURRENCYCODE = 'USD']/RATE")

x = 1
For Each curr In currencies.getElementsByTagName("CURRENCY")
    Response.Write "<p>" & GetText(curr, "NAME") & "</p>"
    Response.Write "<p>" & GetText(curr, "UNIT") & "</p>"
    Response.Write "<p>" & GetText(curr, "CURRENCYCODE") & "</p>"
    Response.Write "<p>" & GetText(curr, "COUNTRY") & "</p>"
    Response.Write "<p>" & GetText(curr, "RATE") & "</p>"
    Response.Write "<p>" & GetText(curr, "CHANGE") & "</p>"
    Response.Write "<p>___________________<br />" & x & "</p>"
    x = x + 1
Next
' ----------------------------------------------------------------------

' loads an XML document from a URL and returns it
Function LoadXmlDocument(url)
    Set LoadXmlDocument = CreateObject("MSXML2.FreeThreadedDOMDocument.6.0")
    LoadXmlDocument.async = False
    LoadXmlDocument.setProperty "ServerHTTPRequest", True
    LoadXmlDocument.setProperty "SelectionLanguage", "XPath"
    LoadXmlDocument.Load url
    If LoadXmlDocument.parseError <> 0 Then
        Err.Raise vbObjectError + 1, _
            "LoadXmlDocument", _
            "Cannot load " & url & " (" & LoadXmlDocument.parseError.reason & ")"
    End If
End Function

' finds the first node that matches the XPath and returns its text value
Function GetText(context, xpath)
    Dim node
    Set node = context.selectSingleNode(xpath)
    If node Is Nothing Then
        GetText = vbEmpty
    Else
        GetText = node.text
    End If
End Function