上篇博客,当没有权限的用户访问一些资源时,返回的是403错误,403对于用户来说是一个莫名其妙的数字,我们当然要处理成友好的提示。
关于错误处理,翻看了一下Nancy的源码,是这样处理的,见下面地址:
https://github.com/NancyFx/Nancy/blob/master/src/Nancy/ErrorHandling/DefaultStatusCodeHandler.cs
其实Nancy是允许我们采用相同的办法处理,现在把DefaultStatusCodeHandler.cs的源码复制下来,改成我们自己的CustomStatusCode.cs如下,关于详细说明,参考Nancy源码DefaultStatusCodeHandler.cs。
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
|
using Nancy;
using Nancy.ErrorHandling;
using Nancy.ViewEngines;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using Nancy.Responses.Negotiation;
using Nancy.Extensions;
using Nancy.IO;
namespace NancySelfHostWeb
{ public class CustomStatusCode: IStatusCodeHandler
{
private const string DisableErrorTracesTrueMessage = "Error details are currently disabled. Please set <code>StaticConfiguration.DisableErrorTraces = false;</code> to enable." ;
private readonly IDictionary<HttpStatusCode, string > errorMessages;
private readonly IDictionary<HttpStatusCode, string > errorPages;
private readonly IResponseNegotiator responseNegotiator;
private readonly HttpStatusCode[] supportedStatusCodes = { HttpStatusCode.Forbidden, HttpStatusCode.NotFound};
public CustomStatusCode(IResponseNegotiator responseNegotiator)
{
this .errorMessages = new Dictionary<HttpStatusCode, string >
{
{ HttpStatusCode.Forbidden, "查看是否有授权!" },
{ HttpStatusCode.NotFound, "找不到你要的资源!" }
};
this .errorPages = new Dictionary<HttpStatusCode, string >
{
{ HttpStatusCode.Forbidden, LoadResource( "NancySelfHostWeb.403.html" ) },
{ HttpStatusCode.NotFound, LoadResource( "NancySelfHostWeb.404.html" ) }
};
this .responseNegotiator = responseNegotiator;
}
public bool HandlesStatusCode(HttpStatusCode statusCode, NancyContext context)
{
return this .supportedStatusCodes.Any(s => s == statusCode);
}
public void Handle(HttpStatusCode statusCode, NancyContext context)
{
if (context.Response != null && context.Response.Contents != null && !ReferenceEquals(context.Response.Contents, Response.NoBody))
{
return ;
}
if (! this .errorMessages.ContainsKey(statusCode) || ! this .errorPages.ContainsKey(statusCode))
{
return ;
}
Response existingResponse = null ;
if (context.Response != null )
{
existingResponse = context.Response;
}
context.NegotiationContext = new NegotiationContext();
var result = new DefaultStatusCodeHandlerResult(statusCode, this .errorMessages[statusCode], StaticConfiguration.DisableErrorTraces ? DisableErrorTracesTrueMessage : context.GetExceptionDetails());
try
{
context.Response = this .responseNegotiator.NegotiateResponse(result, context);
context.Response.StatusCode = statusCode;
if (existingResponse != null )
{
context.Response.ReasonPhrase = existingResponse.ReasonPhrase;
}
return ;
}
catch (ViewNotFoundException)
{
}
this .ModifyResponse(statusCode, context, result);
}
private void ModifyResponse(HttpStatusCode statusCode, NancyContext context, DefaultStatusCodeHandlerResult result)
{
if (context.Response == null )
{
context.Response = new Response { StatusCode = statusCode };
}
var contents = this .errorPages[statusCode];
if (! string .IsNullOrEmpty(contents))
{
contents = contents.Replace( "[DETAILS]" , result.Details);
}
context.Response.ContentType = "text/html" ;
context.Response.Contents = s =>
{
using ( var writer = new StreamWriter( new UnclosableStreamWrapper(s), Encoding.UTF8))
{
writer.Write(contents);
}
};
}
private static string LoadResource( string filename)
{
// 获取当前资源文件
var resourceStream = typeof (CustomStatusCode).Assembly.GetManifestResourceStream( string .Format( "{0}" , filename));
if (resourceStream == null )
{
return string .Empty;
}
using ( var reader = new StreamReader(resourceStream))
{
return reader.ReadToEnd();
}
}
internal class DefaultStatusCodeHandlerResult
{
public DefaultStatusCodeHandlerResult(HttpStatusCode statusCode, string message, string details)
{
this .StatusCode = statusCode;
this .Message = message;
this .Details = details;
}
public HttpStatusCode StatusCode { get ; private set ; }
public string Message { get ; private set ; }
public string Details { get ; private set ; }
}
}
} |
这样还可以把Nancy内置的500,404错误改成我们自定义的显示。
有时觉得这样太麻烦,可以自大在Module中去判断登录用户是否具有角色,代码如下
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
|
using Nancy;
using Nancy.Security;
using System.Linq;
namespace TestSelfHostWeb.Modules
{ public class IndexModule : NancyModule
{
public IndexModule()
{
//开启全局验证
this .RequiresAuthentication();
Get[ "/" ] = parameters =>
{
//开启角色验证,只有该角色可以访问本路由
//this.RequiresClaims("admin");
//自己判断登录角色具有权限
if (! this .Context.CurrentUser.Claims.Contains( "admin" ))
{
return View[ "error" ]; //定义一个错误页面error.cshtml即可
}
return View[ "index" ];
};
}
}
} |