修复无效 JSON 的最有效方法

Question

我陷入了一个不可能的境地。我有一个来自外部 space 的 JSON（他们无法更改它）。这是 JSON

{
    user:'180111',
    title:'I\'m sure "E pluribus unum" means \'Out of Many, One.\' \n\nhttp://en.wikipedia.org/wiki/E_pluribus_unum.\n\n\'',
    date:'2007/01/10 19:48:38',
    "id":"3322121",
    "previd":112211,
    "body":"\'You\' can \"read\" more here [url=http:\/\/en.wikipedia.org\/?search=E_pluribus_unum]E pluribus unum[\/url]'s. Cheers \*/ :\/",
    "from":"112221",
    "username":"mikethunder",
    "creationdate":"2007\/01\/10 14:04:49"
}

"It is nowhere near a valid JSON",我说。他们的回应是 "emmm! but Javascript can read it without complain":

<html>
<script type="text/javascript">
    var obj = {"PUT JSON FROM UP THERE HERE"};

    document.write(obj.title);
    document.write("<br />");
    document.write(obj.creationdate + " " + obj.date);
    document.write("<br />");
    document.write(obj.body);
    document.write("<br />");
</script>
<body>
</body>
</html>

问题

我应该通过 .NET(4) 读取和解析这个字符串，它破坏了 Json.org 的 C# 部分中提到的 14 个库中的 3 个（没有尝试其余的）。为了解决问题，我编写了以下函数来解决单引号和双引号的问题。

public static string JSONBeautify(string InStr){
    bool inSingleQuote = false;
    bool inDoubleQuote = false;
    bool escaped = false;

    StringBuilder sb = new StringBuilder(InStr);
    sb = sb.Replace("`", "<°)))><"); // replace all instances of "grave accent" to "fish" so we can use that mark later. 
                                        // Hopefully there is no "fish" in our JSON
    for (int i = 0; i < sb.Length; i++) {
        switch (sb[i]) {

            case '\':
                if (!escaped)
                    escaped = true;
                else 
                    escaped = false;
                break;
            case '\'':
                if (!inSingleQuote && !inDoubleQuote) {
                    sb[i] = '"';            // Change opening single quote string markers to double qoute
                    inSingleQuote = true;
                } else if (inSingleQuote && !escaped) {
                    sb[i] = '"';            // Change closing single quote string markers to double qoute
                    inSingleQuote = false;
                } else if (escaped) {
                    escaped = false;
                }
                break;
            case '"':
                if (!inSingleQuote && !inDoubleQuote) {
                    inDoubleQuote = true;   // This is a opening double quote string marker
                } else if (inSingleQuote && !escaped) {
                    sb[i] = '`';            // Change unescaped double qoute to grave accent
                } else if (inDoubleQuote && !escaped) {
                    inDoubleQuote = false; // This is a closing double quote string marker
                } else if (escaped) {
                    escaped = false;
                }
                break;
            default:
                escaped = false;
                break;
        }
    }
    return sb.ToString()
        .Replace("\/", "/")        // Remove all instances of escaped / (\/) .hopefully no smileys in string
        .Replace("`", "\\"")       // Change all "grave accent"s to escaped double quote \"
        .Replace("<°)))><", "`")   // change all fishes back to "grave accent"
        .Replace("\'","'");        // change all escaped single quotes to just single quote
}

现在 JSONlint 只会抱怨属性名称，我可以同时使用 JSON.NET 和 SimpleJSON 库来解析 JSON.

问题

我确信我的代码不是上述修复的最佳方法 JSON。是否存在我的代码可能会中断的情况？有更好的方法吗？

Answer 1

您需要运行通过 JavaScript。在 .net 中启动 JavaScript 解析器。将字符串作为输入给JavaScript，使用JavaScript的原生JSON.stringify转换：

obj = {
    "user":'180111',
    "title":'I\'m sure "E pluribus unum" means \'Out of Many, One.\' \n\nhttp://en.wikipedia.org/wiki/E_pluribus_unum.\n\n',
    "date":'2007/01/10 19:48:38',
    "id":"3322121",
    "previd":"112211",
    "body":"\'You\' can \"read\" more here [url=http:\/\/en.wikipedia.org\/?search=E_pluribus_unum]E pluribus unum[\/url]'s. Cheers \*/ :\/",
    "from":"112221",
    "username":"mikethunder",
    "creationdate":"2007\/01\/10 14:04:49"
}

console.log(JSON.stringify(obj));
document.write(JSON.stringify(obj));

请记住，您获得的字符串（或对象）无效 JSON 并且无法使用 JSON 库进行解析。它需要首先转换为有效的JSON。但是它是有效的 JavaScript.

要完成此答案：您可以在 .Net 中使用 JavaScriptSerializer。对于此解决方案，您需要以下程序集：

System.Net

System.Web.Script.Serialization

var webClient = new WebClient();
string readHtml = webClient.DownloadString("uri to your source (extraterrestrial)");
var a = new JavaScriptSerializer();

Dictionary<string, object> results = a.Deserialize<Dictionary<string, object>>(readHtml);

Answer 2

这个怎么样：

 string AlienJSON = "your alien JSON";
 JavaScriptSerializer js = new JavaScriptSerializer();
 string ProperJSON = js.Serialize(js.DeserializeObject(AlienJSON));

或者只是在反序列化后使用对象，而不是将其转换回字符串并将其传递给 JSON 解析器，这会让人头疼

正如 Mouser 还提到的，您需要在项目中使用 System.Web.Script.Serialization which is available by including system.web.extensions.dll，为此您需要将项目属性中的 Target 框架更改为 .NET Framework 4。

编辑

消费反序列化对象的技巧是使用dynamic

JavaScriptSerializer js = new JavaScriptSerializer();
dynamic obj = js.DeserializeObject(AlienJSON);

for JSON 在你的问题中只需使用

string body = obj["body"];

或者如果您的 JSON 是数组

if (obj is Array) {
    foreach(dynamic o in obj){
        string body = obj[0]["body"];
        // ... do something with it
    }
}

Answer 3

这是我制作的一个功能，可以修复损坏的 json:

function fixJSON(json){
    function bulkRegex(str, callback){
        if(callback && typeof callback === 'function'){
            return callback(str);
        }else if(callback && Array.isArray(callback)){
            for(let i = 0; i < callback.length; i++){
                if(callback[i] && typeof callback[i] === 'function'){
                    str = callback[i](str);
                }else{break;}
            }
            return str;
        }
        return str;
    }
    if(json && json !== ''){
        if(typeof json !== 'string'){
            try{
                json = JSON.stringify(json);
            }catch(e){return false;}
        }
        if(typeof json === 'string'){
            json = bulkRegex(json, false, [
                str => str.replace(/[\n\t]/gm, ''),
                str => str.replace(/,\}/gm, '}'),
                str => str.replace(/,\]/gm, ']'),
                str => {
                    str = str.split(/(?=[,\}\]])/g);
                    str = str.map(s => {
                        if(s.includes(':') && s){
                            let strP = s.split(/:(.+)/, 2);
                            strP[0] = strP[0].trim();
                            if(strP[0]){
                                let firstP = strP[0].split(/([,\{\[])/g);
                                firstP[firstP.length-1] = bulkRegex(firstP[firstP.length-1], false, p => p.replace(/[^A-Za-z0-9\-_]/, ''));
                                strP[0] = firstP.join('');
                            }
                            let part = strP[1].trim();
                            if((part.startsWith('"') && part.endsWith('"')) || (part.startsWith('\'') && part.endsWith('\'')) || (part.startsWith('`') && part.endsWith('`'))){
                                part = part.substr(1, part.length - 2);
                            }
                            part = bulkRegex(part, false, [
                                p => p.replace(/(["])/gm, '\'),
                                p => p.replace(/\'/gm, '\''),
                                p => p.replace(/\`/gm, '`'),
                            ]);
                            strP[1] = ('"'+part+'"').trim();
                            s = strP.join(':');
                        }
                        return s;
                    });
                    return str.join('');
                },
                str => str.replace(/(['"])?([a-zA-Z0-9\-_]+)(['"])?:/g, '"":'),
                str => {
                    str = str.split(/(?=[,\}\]])/g);
                    str = str.map(s => {
                        if(s.includes(':') && s){
                            let strP = s.split(/:(.+)/, 2);
                            strP[0] = strP[0].trim();
                            if(strP[1].includes('"') && strP[1].includes(':')){
                                let part = strP[1].trim();
                                if(part.startsWith('"') && part.endsWith('"')){
                                    part = part.substr(1, part.length - 2);
                                    part = bulkRegex(part, false, p => p.replace(/(?<!\)"/gm, ''));
                                }
                                strP[1] = ('"'+part+'"').trim();
                            }
                            s = strP.join(':');
                        }
                        return s;
                    });
                    return str.join('');
                },
            ]);
            try{
                json = JSON.parse(json);
            }catch(e){return false;}
        }
        return json;
    }
    return false;
}

修复无效 JSON 的最有效方法

Most efficient way to fix an invalid JSON

javascript

c#

json

.net-4.0

fastjson