【发布时间】:2017-05-29 13:11:35
【问题描述】:
我正在尝试将 900000 条记录(每条 12 列)序列化为一个 JSON 对象,并通过 .NET 中的 HTTP 将其流式传输。我遇到了内存不足异常,因为看起来对象最初是创建然后流式传输的(我通过调试应用程序实现了这一点)。到目前为止,这是我的代码:
public class JsonStreamingResult : ActionResult
{
private IEnumerable itemsToSerialize;
public JsonStreamingResult(IEnumerable itemsToSerialize)
{
this.itemsToSerialize = itemsToSerialize;
}
public override void ExecuteResult(ControllerContext context)
{
var response = context.HttpContext.Response;
response.ContentType = "application/json";
response.ContentEncoding = System.Text.Encoding.UTF8;
JsonSerializer serializer = new JsonSerializer();
object itm;
using (StreamWriter sw = new StreamWriter(response.OutputStream))
using (JsonTextWriter writer = new JsonTextWriter(sw))
{
writer.WriteStartArray();
foreach (object item in itemsToSerialize)
{
Newtonsoft.Json.Linq.JObject obj = Newtonsoft.Json.Linq.JObject.FromObject(item, serializer);
obj.WriteTo(writer);
writer.Flush();
}
writer.WriteEndArray();
}
}
}
public class HomeController : Controller
{
public ActionResult Index()
{
return View();
}
public ActionResult streamMason(int id)
{
var masonItems = new List<object>();
DataContext dc = new DataContext();
var viewData = dc.Articles.GetPublishedArticles(null, id);
int cnt = 0;
for (int i = 0; i < 900000; i++)
{
masonItems.Add(new
{
Field1 = "test1",
Field2 = "test2",
Field3 = "test3",
Field4 = "test4",
Field5 = "test5",
Field6 = "test6",
Field7 = "test7",
Field8 = "test8",
Field9 = "test9",
Field10 = "test10",
Field11 = "test11",
Field12 = "test12"
});
}
return new JsonStreamingResult(masonItems);
}
}
我的问题:是否可以在生成对象的同时进行流式传输?
我的代码基于此:Streaming large list of data as JSON format using Json.net
编辑:当我尝试使用较少的记录(最多约 300000 条)进行序列化时,它按预期工作。
【问题讨论】:
-
通过调试应用程序,我意识到它在
writer.WriteEndArray();之后内存不足。似乎首先对象被序列化,然后通过 HTTP 发送。是否可以使用 Async 并行执行这些操作?
标签: c# .net json serialization stream