/// <summary>
/// 反序列化方式
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="json"></param>
/// <param name="type"></param>
/// <returns></returns>
private static List <T> Convert <T>(string json, JsonToolType type)
{
List <T> list = null;
switch (type)
{
case JsonToolType.Newtonsoft:
JsonReader reader = new JsonTextReader(new StringReader(json));
Newtonsoft.Json.Linq.JArray array = (JArray)JToken.ReadFrom(reader);
list = array.ToObject <List <T> >();
break;
case JsonToolType.Swifter:
list = JsonFormatter.DeserializeObject <List <T> >(json);
break;
case JsonToolType.FastJson:
list = fastJSON.JSON.ToObject <List <T> >(json);
break;
default:
break;
}
return(list);
}
/// <summary>
/// 保存json
/// </summary>
///
public static bool SaveJsonFile <T>(List <T> list, string savePath, JsonToolType type, int batchNumber = 1000)
{
if (list == null || list.Count == 0 || string.IsNullOrEmpty(savePath))
{
return(false);
}
if (File.Exists(savePath))
{
File.Delete(savePath);
}
var count = (int)Math.Ceiling((double)list.Count / batchNumber);
bool isFirst = false;
bool isLast = false;
for (var i = 0; i < count; i++)
{
isFirst = false;
isLast = false;
if (i == 0)
{
isFirst = true;
}
if (i == count - 1)
{
isLast = true;
}
var batchList = list.Skip(i * batchNumber).Take(batchNumber).ToList();
SaveJsonBatch <T>(batchList, savePath, isFirst, isLast, type);
}
return(true);
}
/// <summary>
/// 序列化保存测试
/// </summary>
/// <param name="type"></param>
public static void SaveTest(JsonToolType type)
{
var path = Environment.CurrentDirectory + "\\json.txt";
if (File.Exists(path))
{
File.Delete(path);
}
int length = 100000;
List <Student> list = new List <Model.Student>();
for (var i = 0; i < length; i++)
{
Student student = new Model.Student();
student.ID = i;
student.Name = "Student" + i;
student.Mobile = i.ToString();
student.Address = "city" + i.ToString();
list.Add(student);
}
var date1 = DateTime.Now;
SaveJsonFile <Student>(list, path, type, 1000);
var date2 = DateTime.Now;
Console.WriteLine("序列化用时:{0}秒", (date2 - date1).TotalSeconds);
}
/// <summary>
/// 转换为json String
/// </summary>
/// <typeparam name="T"></typeparam>
/// <param name="list"></param>
/// <returns></returns>
private static string ToJson <T>(List <T> list, JsonToolType type, bool isLast)
{
string jsonString = string.Empty;
StringBuilder str = new StringBuilder();
switch (type)
{
case JsonToolType.Newtonsoft:
for (int i = 0; i < list.Count; i++)
{
var item = list[i];
if (i == list.Count - 1 && isLast)
{
str.Append(item.ToJson());
}
else
{
str.Append(item.ToJson() + "," + Environment.NewLine);
}
}
jsonString += str.ToString();
break;
case JsonToolType.Swifter:
for (int i = 0; i < list.Count; i++)
{
var item = list[i];
if (i == list.Count - 1 && isLast)
{
str.Append(JsonFormatter.SerializeObject(item));
}
else
{
str.Append(JsonFormatter.SerializeObject(item) + "," + Environment.NewLine);
}
}
jsonString += str.ToString();
break;
case JsonToolType.FastJson:
for (int i = 0; i < list.Count; i++)
{
var item = list[i];
if (i == list.Count - 1 && isLast)
{
str.Append(fastJSON.JSON.ToJSON(item));
}
else
{
str.Append(fastJSON.JSON.ToJSON(item) + "," + Environment.NewLine);
}
}
jsonString += str.ToString();
break;
}
return(jsonString);
}
/// <summary>
/// 反序列化测试
/// </summary>
/// <param name="type"></param>
public static void ConvertTest(JsonToolType type)
{
var date1 = DateTime.Now;
var path = Environment.CurrentDirectory + "\\json.txt";
var list = ConvertJsonFile <Student>(path, type);
if (list == null)
{
return;
}
var date2 = DateTime.Now;
Console.WriteLine("反序列化用时:{0}秒", (date2 - date1).TotalSeconds);
}
/// <summary>
/// 二进制读取转换
/// </summary>
public static List <T> ConvertJsonFile <T>(string path, JsonToolType type)
{
List <T> returnList = new List <T>();
if (!File.Exists(path))
{
return(returnList);
}
try
{
// 在当前目录创建一个文件myfile.txt，对该文件具有读写权限
FileStream fs = new FileStream(path, FileMode.OpenOrCreate, FileAccess.ReadWrite);
BinaryReader br = new BinaryReader(fs);
// 把文件指针重新定位到文件的开始
br.BaseStream.Seek(0, SeekOrigin.Begin);
// 打印文件文本内容
long start = 0;
long end = 0;
byte[] data = null;
long length = 0;
string jsonString = "";
long MbSize = 8 * 1024 * 1024;
long fileSize = fs.Length;
while (end < fileSize)
{
jsonString = "";
br.BaseStream.Position = start;
//按照块读取
if (MbSize > fileSize)
{
length = fileSize;
}
else
{
length = MbSize;
}
data = new byte[length];
br.Read(data, 0, (int)length);
int index = 0;
//查找最后一次回车的位置
for (var i = data.Length - 1; i > 0; i--)
{
if (data[i] == 13)
{
index = i;
break;
}
}
if (index == 0)
{
index = data.Length - 1;
}
jsonString = System.Text.Encoding.UTF8.GetString(data, 0, index);
if (!jsonString.StartsWith("["))
{
jsonString = "[" + jsonString;
}
if (!jsonString.EndsWith("]"))
{
jsonString = jsonString.TrimEnd('\n').TrimEnd('\r').TrimEnd(',');
jsonString += "]";
}
//根据指定json工具转换
var tempList = Convert <T>(jsonString, type);
returnList.AddRange(tempList);
end = start + index;
start = end;
}
br.Close();
fs.Close();
return(returnList);
}
catch (Exception ex)
{
throw ex;
}
}
/// <summary>
/// 批次保存
/// </summary>
private static void SaveJsonBatch <T>(List <T> list, string path, bool isFirst, bool isLast, JsonToolType type)
{
//实例化一个文件流—>与写入文件相关联
string jsonString = string.Empty;
StringBuilder json = new StringBuilder();
using (StreamWriter sw = new StreamWriter(path, true))
{
if (isFirst)
{
jsonString = "[";
}
jsonString += ToJson <T>(list, type, isLast);
if (isLast)
{
jsonString += "]";
}
//开始写入
sw.Write(jsonString);
//清空缓冲区
sw.Flush();
//关闭流
sw.Close();
}
}
