标题: 用VBS解析JSON格式数据之VbsJson类
作者: Demon
链接: https://demon.tw/my-work/vbs-json.html
版权: 本博客的所有文章，都遵守“署名-非商业性使用-相同方式共享 2.5 中国大陆”协议条款。
曾经写过一篇《用VBS解析JSON格式数据》，里面提到了用 VBS 解析 JSON 的三种方法：：第一，根据算法自己写一个解析 JSON 的库；第二，使用正则表达式匹配需要的数据；第三，用 JavaScript 来解析。
文章中使用的是第三种方法，即通过 MSScriptControl.ScriptControl 组件来调用 JavaScript 来解析。“乱码”根据那篇文章写了《VBS脚本之JSON数据解析》，稍稍改进了我的方法；不过他最近发现这个组件兼容性不太好，并写了一篇《VBS脚本之JSON数据解析(二)》，里面是用正则表达式来解析 JSON 的；之后又写了一篇《VBS脚本之JSON数据解析(三)[终章]》，里面用 htmlfile 来代替 MSScriptControl.ScriptControl，增强了可移植性：
Function ParseJson(strJson) Set html = CreateObject("htmlfile") Set window = html.parentWindow window.execScript "var json = " & strJson, "JScript" Set ParseJson = window.json End Function
不得不说这个方法很巧妙，但是却不能遍历数组和对象，作为“终章”似乎还差了一点，本文就是作为终章的存在：用 Native VBScript 来解析 JSON —— VbsJson类。该类提供了两个公有方法：Encode 和 Decode，分别用来生成和解析 JSON 数据。
VbsJson.vbs
Class VbsJson 'Author: Demon 'Date: 2012/5/3 'Website: https://demon.tw Private Whitespace, NumberRegex, StringChunk Private b, f, r, n, t Private Sub Class_Initialize Whitespace = " " & vbTab & vbCr & vbLf b = ChrW(8) f = vbFormFeed r = vbCr n = vbLf t = vbTab Set NumberRegex = New RegExp NumberRegex.Pattern = "(-?(?:0|[1-9]\d*))(\.\d+)?([eE][-+]?\d+)?" NumberRegex.Global = False NumberRegex.MultiLine = True NumberRegex.IgnoreCase = True Set StringChunk = New RegExp StringChunk.Pattern = "([\s\S]*?)([""\\\x00-\x1f])" StringChunk.Global = False StringChunk.MultiLine = True StringChunk.IgnoreCase = True End Sub 'Return a JSON string representation of a VBScript data structure 'Supports the following objects and types '+-------------------+---------------+ '| VBScript | JSON | '+===================+===============+ '| Dictionary | object | '+-------------------+---------------+ '| Array | array | '+-------------------+---------------+ '| String | string | '+-------------------+---------------+ '| Number | number | '+-------------------+---------------+ '| True | true | '+-------------------+---------------+ '| False | false | '+-------------------+---------------+ '| Null | null | '+-------------------+---------------+ Public Function Encode(ByRef obj) Dim buf, i, c, g Set buf = CreateObject("Scripting.Dictionary") Select Case VarType(obj) Case vbNull buf.Add buf.Count, "null" Case vbBoolean If obj Then buf.Add buf.Count, "true" Else buf.Add buf.Count, "false" End If Case vbInteger, vbLong, vbSingle, vbDouble buf.Add buf.Count, obj Case vbString buf.Add buf.Count, """" For i = 1 To Len(obj) c = Mid(obj, i, 1) Select Case c Case """" buf.Add buf.Count, "\""" Case "\" buf.Add buf.Count, "\\" Case "/" buf.Add buf.Count, "/" Case b buf.Add buf.Count, "\b" Case f buf.Add buf.Count, "\f" Case r buf.Add buf.Count, "\r" Case n buf.Add buf.Count, "\n" Case t buf.Add buf.Count, "\t" Case Else If AscW(c) >= 0 And AscW(c) <= 31 Then c = Right("0" & Hex(AscW(c)), 2) buf.Add buf.Count, "\u00" & c Else buf.Add buf.Count, c End If End Select Next buf.Add buf.Count, """" Case vbArray + vbVariant g = True buf.Add buf.Count, "[" For Each i In obj If g Then g = False Else buf.Add buf.Count, "," buf.Add buf.Count, Encode(i) Next buf.Add buf.Count, "]" Case vbObject If TypeName(obj) = "Dictionary" Then g = True buf.Add buf.Count, "{" For Each i In obj If g Then g = False Else buf.Add buf.Count, "," buf.Add buf.Count, """" & i & """" & ":" & Encode(obj(i)) Next buf.Add buf.Count, "}" Else Err.Raise 8732,,"None dictionary object" End If Case Else buf.Add buf.Count, """" & CStr(obj) & """" End Select Encode = Join(buf.Items, "") End Function 'Return the VBScript representation of ``str(`` 'Performs the following translations in decoding '+---------------+-------------------+ '| JSON | VBScript | '+===============+===================+ '| object | Dictionary | '+---------------+-------------------+ '| array | Array | '+---------------+-------------------+ '| string | String | '+---------------+-------------------+ '| number | Double | '+---------------+-------------------+ '| true | True | '+---------------+-------------------+ '| false | False | '+---------------+-------------------+ '| null | Null | '+---------------+-------------------+ Public Function Decode(ByRef str) Dim idx idx = SkipWhitespace(str, 1) If Mid(str, idx, 1) = "{" Then Set Decode = ScanOnce(str, 1) Else Decode = ScanOnce(str, 1) End If End Function Private Function ScanOnce(ByRef str, ByRef idx) Dim c, ms idx = SkipWhitespace(str, idx) c = Mid(str, idx, 1) If c = "{" Then idx = idx + 1 Set ScanOnce = ParseObject(str, idx) Exit Function ElseIf c = "[" Then idx = idx + 1 ScanOnce = ParseArray(str, idx) Exit Function ElseIf c = """" Then idx = idx + 1 ScanOnce = ParseString(str, idx) Exit Function ElseIf c = "n" And StrComp("null", Mid(str, idx, 4)) = 0 Then idx = idx + 4 ScanOnce = Null Exit Function ElseIf c = "t" And StrComp("true", Mid(str, idx, 4)) = 0 Then idx = idx + 4 ScanOnce = True Exit Function ElseIf c = "f" And StrComp("false", Mid(str, idx, 5)) = 0 Then idx = idx + 5 ScanOnce = False Exit Function End If Set ms = NumberRegex.Execute(Mid(str, idx)) If ms.Count = 1 Then idx = idx + ms(0).Length ScanOnce = CDbl(ms(0)) Exit Function End If Err.Raise 8732,,"No JSON object could be ScanOnced" End Function Private Function ParseObject(ByRef str, ByRef idx) Dim c, key, value Set ParseObject = CreateObject("Scripting.Dictionary") idx = SkipWhitespace(str, idx) c = Mid(str, idx, 1) If c = "}" Then Exit Function ElseIf c <> """" Then Err.Raise 8732,,"Expecting property name" End If idx = idx + 1 Do key = ParseString(str, idx) idx = SkipWhitespace(str, idx) If Mid(str, idx, 1) <> ":" Then Err.Raise 8732,,"Expecting : delimiter" End If idx = SkipWhitespace(str, idx + 1) If Mid(str, idx, 1) = "{" Then Set value = ScanOnce(str, idx) Else value = ScanOnce(str, idx) End If ParseObject.Add key, value idx = SkipWhitespace(str, idx) c = Mid(str, idx, 1) If c = "}" Then Exit Do ElseIf c <> "," Then Err.Raise 8732,,"Expecting , delimiter" End If idx = SkipWhitespace(str, idx + 1) c = Mid(str, idx, 1) If c <> """" Then Err.Raise 8732,,"Expecting property name" End If idx = idx + 1 Loop idx = idx + 1 End Function Private Function ParseArray(ByRef str, ByRef idx) Dim c, values, value Set values = CreateObject("Scripting.Dictionary") idx = SkipWhitespace(str, idx) c = Mid(str, idx, 1) If c = "]" Then ParseArray = values.Items Exit Function End If Do idx = SkipWhitespace(str, idx) If Mid(str, idx, 1) = "{" Then Set value = ScanOnce(str, idx) Else value = ScanOnce(str, idx) End If values.Add values.Count, value idx = SkipWhitespace(str, idx) c = Mid(str, idx, 1) If c = "]" Then Exit Do ElseIf c <> "," Then Err.Raise 8732,,"Expecting , delimiter" End If idx = idx + 1 Loop idx = idx + 1 ParseArray = values.Items End Function Private Function ParseString(ByRef str, ByRef idx) Dim chunks, content, terminator, ms, esc, char Set chunks = CreateObject("Scripting.Dictionary") Do Set ms = StringChunk.Execute(Mid(str, idx)) If ms.Count = 0 Then Err.Raise 8732,,"Unterminated string starting" End If content = ms(0).Submatches(0) terminator = ms(0).Submatches(1) If Len(content) > 0 Then chunks.Add chunks.Count, content End If idx = idx + ms(0).Length If terminator = """" Then Exit Do ElseIf terminator <> "\" Then Err.Raise 8732,,"Invalid control character" End If esc = Mid(str, idx, 1) If esc <> "u" Then Select Case esc Case """" char = """" Case "\" char = "\" Case "/" char = "/" Case "b" char = b Case "f" char = f Case "n" char = n Case "r" char = r Case "t" char = t Case Else Err.Raise 8732,,"Invalid escape" End Select idx = idx + 1 Else char = ChrW("&H" & Mid(str, idx + 1, 4)) idx = idx + 5 End If chunks.Add chunks.Count, char Loop ParseString = Join(chunks.Items, "") End Function Private Function SkipWhitespace(ByRef str, ByVal idx) Do While idx <= Len(str) And _ InStr(Whitespace, Mid(str, idx, 1)) > 0 idx = idx + 1 Loop SkipWhitespace = idx End Function End Class
Example.vbs
'Author: Demon 'Date: 2012/5/3 'Website: https://demon.tw Dim fso, json, str, o, i Set json = New VbsJson Set fso = WScript.CreateObject("Scripting.Filesystemobject") str = fso.OpenTextFile("json.txt").ReadAll Set o = json.Decode(str) WScript.Echo o("Image")("Width") WScript.Echo o("Image")("Height") WScript.Echo o("Image")("Title") WScript.Echo o("Image")("Thumbnail")("Url") For Each i In o("Image")("IDs") WScript.Echo i Next
json.txt
{
"Image": {
"Width": 800,
"Height": 600,
"Title": "View from 15th Floor",
"Thumbnail": {
"Url": "http://www.example.com/image/481989943",
"Height": 125,
"Width": "100"
},
"IDs": [116, 943, 234, 38793]
}
}
欢迎测试和反馈BUG。
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随机文章:
bravo, great class. thanks!!!!
Thank you very much for this useful script, only one question, i don’t understand how to resolve json arrays such as:
[{
“Image”: {
“Width”: 800,
“Height”: 600},
{
“Image”: {
“Width”: 900,
“Height”: 700}]
can you help me please?
thanks in advance.
see this http://www.dovetailsoftware.com/blogs/gsherman/archive/2008/10/22/consuming-json-in-clearbasic
请问,用这个代码如何判断o(“Image”)(“Height”) 和 o(“Image”)(“Thumbnail”)(“Url”)
的类型? 1个是字符串 1个是变体数组
如果不判断,不知道有没有下一层….
还有如何判断Image -> 下层里有没有 Height 这个层呢,用exists貌似不可以,那怎么判断呢
Thank you! Nicely done!
not working for arrays… any help plz
代码写得不错，不过o(“Image”)(“Width”) 这种方式看着蛋痛，元素不存在时容易引起错误。
个人觉得 使用 MSScriptControl.ScriptControl， 把json 转成xml，然后在vbs 里调用xml 是不错的方式。
貌似utf-8的编码有些问题。
在UTF-8下没有问题。另外可以用TypeName来判断是子json对象还是数组。但是怎么判断有子对象不知道怎么搞。
同样可以用TypeName来判断是否有该子对象，为Empty表示没有。