ASP.NET Core Web Api中间件自定义异常
ASP.NET Core Web Api中间件将自定义异常转换为基本异常
ASP.NET Core Web Api Middleware Converts Custom Exception into Base Exception
我创建了一个自定义异常类,并使用它引发异常.中间件捕获了它,但是抛出了基本异常而不是自定义异常.我不明白为什么它不能捕获自定义异常.
I have created a custom exception class and use it throw an exception. The middleware catches it but throws base exception instead of custom exception. I am not able to understand why it does not catch custom exception.
自定义例外
Custom Exception
public class CustomException : Exception
{
public int HttpStatusCode { get; private set; }
public CustomException()
{
}
public CustomException(int httpStatusCode, string message):base(message)
{
HttpStatusCode = httpStatusCode;
}
}
中间件
Middleware
public class ExceptionMiddleware
{
public readonly RequestDelegate _next;
public ExceptionMiddleware(RequestDelegate next)
{
_next = next;
}
public async Task InvokeAsync(HttpContext httpContext)
{
try
{
await _next(httpContext);
}
catch(CustomException ex)
{
await HandleExceptionAsync(httpContext, ex);
}
catch(Exception ex)
{
await HandleExceptionAsync(httpContext, ex);
}
}
private static Task HandleExceptionAsync(HttpContext context, Exception ex)
{
int statusCode = (int)HttpStatusCode.InternalServerError;
if (ex is CustomException)
{
CustomException se = ex as CustomException;
statusCode = se.HttpStatusCode;
}
context.Response.ContentType = "application/json";
context.Response.StatusCode = statusCode;
return context.Response.WriteAsync(JsonConvert.SerializeObject(new InternalServerErrorResponse(ex.Message)));
}
}
引发异常
Exception thrown
throw new CustomException(StatusCodes.Status422UnprocessableEntity, "User is already registered!");
引发异常时,中间件不会捕获自定义异常,而是基本Exception.它总是转到下面的代码块
When exception is thrown, middleware does not catch custom exception but base Exception. It always goes to the below code block
catch(Exception ex)
{
await HandleExceptionAsync(httpContext, ex);
}
请告知.
您可以使用异常过滤器来处理异常并轻松操纵响应.
You can use exception filter to handle exceptions and easily manipulate response.
public class ExceptionFilter : IExceptionFilter
{
public ExceptionFilter(IHostingEnvironment env, ILogger<JsonExceptionFilter> logger)
{
_env = env;
_logger = logger;
}
public void OnException(ExceptionContext context)
{
var error = new ApiResponse();
var exceptionName = context.Exception.GetType().Name;
var message = context.Exception.Message;
if (_env.IsDevelopment())
{
error.Message = context.Exception.Message;
error.Detail = context.Exception.StackTrace;
}
else
{
//Prevent To Show Exception Messages On Production
error.Message = "Server Error Occured";
error.Detail = "Something wrong happened";
}
context.Result = new ObjectResult(error)
{
//Manipulate Status Code
StatusCode = 500
};
}
}
并注册到Startup.cs
And register to Startup.cs
public void ConfigureServices(IServiceCollection services){
services.AddMvc(options =>
{
//Catch the exceptions
options.Filters.Add<ExceptionFilter>();
}).SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
}