浅析ASP.NET万能JSON解析器

概念介绍
还是先简单说说json的一些例子吧。注意，以下概念是我自己定义的，可以参考.net里面的type的模型设计
如果有争议，欢迎提出来探讨！

1.最简单：
{"total":0}
total就是值，值是数值，等于0

2. 复杂点
{"total":0,"data":{"377149574" : 1}}
total是值，data是对象，这个对象包含了"377149574"这个值，等于1

3. 最复杂
{"total":0,"data":{"377149574":[{"cid":"377149574"}]}}
total是值，data是对象,377149574是数组，这个数组包含了一些列的对象，例如{"cid":"377149574"}这个对象。

有了以上的概念，就可以设计出通用的json模型了。

万能json源码：

using system;
using system.collections.generic;
using system.text;
namespace pixysoft.json
{
    public class commonjsonmodelanalyzer
    {
        protected string _getkey(string rawjson)
        {
            if (string.isnullorempty(rawjson))
                return rawjson;
            rawjson = rawjson.trim();
            string[] jsons = rawjson.split(new char[] { ':' });
            if (jsons.length < 2)
                return rawjson;
            return jsons[0].replace("\"", "").trim();
        }
        protected string _getvalue(string rawjson)
        {
            if (string.isnullorempty(rawjson))
                return rawjson;
            rawjson = rawjson.trim();
            string[] jsons = rawjson.split(new char[] { ':' }, stringsplitoptions.removeemptyentries);
            if (jsons.length < 2)
                return rawjson;
            stringbuilder builder = new stringbuilder();
            for (int i = 1; i < jsons.length; i++)
            {
                builder.append(jsons[i]);
                builder.append(":");
            }
            if (builder.length > 0)
                builder.remove(builder.length - 1, 1);
            string value = builder.tostring();
            if (value.startswith("\""))
                value = value.substring(1);
            if (value.endswith("\""))
                value = value.substring(0, value.length - 1);
            return value;
        }
        protected list<string> _getcollection(string rawjson)
        {
            //[{},{}]
            list<string> list = new list<string>();
            if (string.isnullorempty(rawjson))
                return list;
            rawjson = rawjson.trim();
            stringbuilder builder = new stringbuilder();
            int nestlevel = -1;
            int mnestlevel = -1;
            for (int i = 0; i < rawjson.length; i++)
            {
                if (i == 0)
                    continue;
                else if (i == rawjson.length - 1)
                    continue;
                char jsonchar = rawjson[i];
                if (jsonchar == '{')
                {
                    nestlevel++;
                }
                if (jsonchar == '}')
                {
                    nestlevel--;
                }
                if (jsonchar == '[')
                {
                    mnestlevel++;
                }
                if (jsonchar == ']')
                {
                    mnestlevel--;
                }
                if (jsonchar == ',' && nestlevel == -1 && mnestlevel == -1)
                {
                    list.add(builder.tostring());
                    builder = new stringbuilder();
                }
                else
                {
                    builder.append(jsonchar);
                }
            }
            if (builder.length > 0)
                list.add(builder.tostring());
            return list;
        }
    }
}

using system;
using system.collections.generic;
using system.text;
namespace pixysoft.json
{
    public class commonjsonmodel : commonjsonmodelanalyzer
    {
        private string rawjson;
        private bool isvalue = false;
        private bool ismodel = false;
        private bool iscollection = false;
        internal commonjsonmodel(string rawjson)
        {
            this.rawjson = rawjson;
            if (string.isnullorempty(rawjson))
                throw new exception("missing rawjson");
            rawjson = rawjson.trim();
            if (rawjson.startswith("{"))
            {
                ismodel = true;
            }
            else if (rawjson.startswith("["))
            {
                iscollection = true;
            }
            else
            {
                isvalue = true;
            }
        }
        public string rawjson
        {
            get { return rawjson; }
        }
        public bool isvalue()
        {
            return isvalue;
        }
        public bool isvalue(string key)
        {
            if (!ismodel)
                return false;
            if (string.isnullorempty(key))
                return false;
            foreach (string subjson in base._getcollection(this.rawjson))
            {
                commonjsonmodel model = new commonjsonmodel(subjson);
                if (!model.isvalue())
                    continue;
                if (model.key == key)
                {
                    commonjsonmodel submodel = new commonjsonmodel(model.value);
                    return submodel.isvalue();
                }
            }
            return false;
        }
        public bool ismodel()
        {
            return ismodel;
        }
        public bool ismodel(string key)
        {
            if (!ismodel)
                return false;
            if (string.isnullorempty(key))
                return false;
            foreach (string subjson in base._getcollection(this.rawjson))
            {
                commonjsonmodel model = new commonjsonmodel(subjson);
                if (!model.isvalue())
                    continue;
                if (model.key == key)
                {
                    commonjsonmodel submodel = new commonjsonmodel(model.value);
                    return submodel.ismodel();
                }
            }
            return false;
        }
        public bool iscollection()
        {
            return iscollection;
        }
        public bool iscollection(string key)
        {
            if (!ismodel)
                return false;
            if (string.isnullorempty(key))
                return false;
            foreach (string subjson in base._getcollection(this.rawjson))
            {
                commonjsonmodel model = new commonjsonmodel(subjson);
                if (!model.isvalue())
                    continue;
                if (model.key == key)
                {
                    commonjsonmodel submodel = new commonjsonmodel(model.value);
                    return submodel.iscollection();
                }
            }
            return false;
        }

        /// <summary>
        /// 当模型是对象，返回拥有的key
        /// </summary>
        /// <returns></returns>
        public list<string> getkeys()
        {
            if (!ismodel)
                return null;
            list<string> list = new list<string>();
            foreach (string subjson in base._getcollection(this.rawjson))
            {
                string key = new commonjsonmodel(subjson).key;
                if (!string.isnullorempty(key))
                    list.add(key);
            }
            return list;
        }
        /// <summary>
        /// 当模型是对象，key对应是值，则返回key对应的值
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public string getvalue(string key)
        {
            if (!ismodel)
                return null;
            if (string.isnullorempty(key))
                return null;
            foreach (string subjson in base._getcollection(this.rawjson))
            {
                commonjsonmodel model = new commonjsonmodel(subjson);
                if (!model.isvalue())
                    continue;
                if (model.key == key)
                    return model.value;
            }
            return null;
        }
        /// <summary>
        /// 模型是对象，key对应是对象，返回key对应的对象
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public commonjsonmodel getmodel(string key)
        {
            if (!ismodel)
                return null;
            if (string.isnullorempty(key))
                return null;
            foreach (string subjson in base._getcollection(this.rawjson))
            {
                commonjsonmodel model = new commonjsonmodel(subjson);
                if (!model.isvalue())
                    continue;
                if (model.key == key)
                {
                    commonjsonmodel submodel = new commonjsonmodel(model.value);
                    if (!submodel.ismodel())
                        return null;
                    else
                        return submodel;
                }
            }
            return null;
        }
        /// <summary>
        /// 模型是对象，key对应是集合，返回集合
        /// </summary>
        /// <param name="key"></param>
        /// <returns></returns>
        public commonjsonmodel getcollection(string key)
        {
            if (!ismodel)
                return null;
            if (string.isnullorempty(key))
                return null;
            foreach (string subjson in base._getcollection(this.rawjson))
            {
                commonjsonmodel model = new commonjsonmodel(subjson);
                if (!model.isvalue())
                    continue;
                if (model.key == key)
                {
                    commonjsonmodel submodel = new commonjsonmodel(model.value);
                    if (!submodel.iscollection())
                        return null;
                    else
                        return submodel;
                }
            }
            return null;
        }
        /// <summary>
        /// 模型是集合，返回自身
        /// </summary>
        /// <returns></returns>
        public list<commonjsonmodel> getcollection()
        {
            list<commonjsonmodel> list = new list<commonjsonmodel>();
            if (isvalue())
                return list;
            foreach (string subjson in base._getcollection(rawjson))
            {
                list.add(new commonjsonmodel(subjson));
            }
            return list;
        }
 

        /// <summary>
        /// 当模型是值对象，返回key
        /// </summary>
        private string key
        {
            get
            {
                if (isvalue())
                    return base._getkey(rawjson);
                return null;
            }
        }
        /// <summary>
        /// 当模型是值对象，返回value
        /// </summary>
        private string value
        {
            get
            {
                if (!isvalue())
                    return null;
                return base._getvalue(rawjson);
            }
        }
    }
}

使用方法

public commonjsonmodel deserialize(string json)
{
 return new commonjsonmodel(json);
}

超级简单，只要new一个通用对象，把json字符串放进去就行了。

针对上文的3个例子，我给出3种使用方法:

{"total":0}
commonjsonmodel model = deserialize(json);
model.getvalue("total") // return 0
{"total":0,"data":{"377149574" : 1}}
commonjsonmodel model = deserialize(json);
model.getmodel("data").getvalue("377149574") //return 1
{"total":0,"data":{"377149574":[{"cid":"377149574"}]}}
commonjsonmodel model = deserialize(json);
model.getcollection("377149574").getcollection()[0].getvalue("cid") //return 377149574

这个有点点复杂，

1. 首先377149574代表了一个集合，所以要用model.getcollection("377149574")把这个集合取出来。

2. 其次这个集合里面包含了很多对象，因此用getcolllection()把这些对象取出来

3. 在这些对象list里面取第一个[0]，表示取了":{"cid":"377149574"}这个对象，然后再用getvalue("cid"）把对象的值取出来。