前言
AutoWrapper是一个简单可自定义全局异常处理程序和ASP.NET Core API响应的包装。他使用ASP.NET Core middleware拦截传入的HTTP请求，并将最后的结果使用统一的格式来自动包装起来.目的主要是让我们更多的关注业务特定的代码要求，并让包装器自动处理HTTP响应。这可以在构建API时加快开发时间，同时为HTTP响应试试我们统一的标准。
安装
AutoWrapper.Core从NuGet或通过CLI下载并安装
PM> Install-Package AutoWrapper.Core
在Startup.cs Configure方法中注册以下内容，但是切记要放在UseRouting前
app.UseApiResponseAndExceptionWrapper();
启动属性映射
默认情况下AutoWrapper将在成功请求成功时输出以下格式：
{
"message": "Request successful.",
"isError": false,
"result": [
{
"id": 7002,
"firstName": "Vianne",
"lastName": "Durano",
"dateOfBirth": "2018-11-01T00:00:00"
}
]
}
如果说不喜欢默认属性命名方式，那么我们可以通过AutoWrapperPropertyMap属性进行映射为我们需要指定的任何名称。例如我么可以将result属性的名称更改为data。如下所示
public class MapResponseObject
{
[AutoWrapperPropertyMap(Prop.Result)]
public object Data { get; set; }
}
然后将MapResponseObject类传递给AutpWrapper middleware
app.UseApiResponseAndExceptionWrapper<MapResponseObject>();
通过映射重新请求后，现在影响格式如下所示
{
"message": "Request successful.",
"isError": false,
"data": {
"id": 7002,
"firstName": "Vianne",
"lastName": "Durano",
"dateOfBirth": "2018-11-01T00:00:00"
}
}
可以从中看出result属性已经更换为data属性了
默认情况下AutoWrapper发生异常时将吐出以下响应格式
{
"isError": true,
"responseException": {
"exceptionMessage": "Unhandled Exception occurred. Unable to process the request."
}
}
而且如果在AutoWrapperOptions中设置了IsDebug，则将产生带有堆栈跟踪信息的类似信息
{
"isError": true,
"responseException": {
"exceptionMessage": " Input string was not in a correct format.",
"details": " at System.Number.ThrowOverflowOrFormatException(ParsingStatus status, TypeCode type)rn at System.Number.ParseInt32(ReadOnlySpan`1 value, NumberStyles styles, NumberFormatInfo info)rn …"
}
}
如果想将某些APIError属性名称更改为其他名称，只需要在以下代码中添加以下映射MapResponseObject
public class MapResponseObject
{
[AutoWrapperPropertyMap(Prop.ResponseException)]
public object Error { get; set; }
[AutoWrapperPropertyMap(Prop.ResponseException_ExceptionMessage)]
public string Message { get; set; }
[AutoWrapperPropertyMap(Prop.ResponseException_Details)]
public string StackTrace { get; set; }
}
通过如下代码来模拟错误
int num = Convert.ToInt32("10s");
现在映射后的输出如下所示
{
"isError": true,
"error": {
"message": " Input string was not in a correct format.",
"stackTrace": " at System.Number.ThrowOverflowOrFormatException(ParsingStatus status, TypeCode type)rn at System.Number.ParseInt32(ReadOnlySpan`1 value, NumberStyles styles, NumberFormatInfo info)rn …"
}
}
请注意APIError现在根据MapResponseObject类中定义的属性更改了模型的默认属性。
我们可以自由的选择映射任何属性，下面是映射属性相对应的列表
[AutoWrapperPropertyMap(Prop.Version)]
[AutoWrapperPropertyMap(Prop.StatusCode)]
[AutoWrapperPropertyMap(Prop.Message)]
[AutoWrapperPropertyMap(Prop.IsError)]
[AutoWrapperPropertyMap(Prop.Result)]
[AutoWrapperPropertyMap(Prop.ResponseException)]
[AutoWrapperPropertyMap(Prop.ResponseException_ExceptionMessage)]
[AutoWrapperPropertyMap(Prop.ResponseException_Details)]
[AutoWrapperPropertyMap(Prop.ResponseException_ReferenceErrorCode)]
[AutoWrapperPropertyMap(Prop.ResponseException_ReferenceDocumentLink)]
[AutoWrapperPropertyMap(Prop.ResponseException_ValidationErrors)]
[AutoWrapperPropertyMap(Prop.ResponseException_ValidationErrors_Field)]
[AutoWrapperPropertyMap(Prop.ResponseException_ValidationErrors_Message)]
自定义错误架构
AutoWrapper还提供了一个APIException可用于定义自己的异常的对象，如果想抛出自己的异常消息，则可以简单地执行以下操作
throw new ApiException("Error blah", 400, "511", "http://blah.com/error/511");
默认输出格式如下所示
{
"isError": true,
"responseException": {
"exceptionMessage": "Error blah",
"referenceErrorCode": "511",
"referenceDocumentLink": "http://blah.com/error/511"
}
}
当然我们可以自定义错误格式
public class MapResponseObject
{
[AutoWrapperPropertyMap(Prop.ResponseException)]
public object Error { get; set; }
}
public class Error
{
public string Message { get; set; }
public string Code { get; set; }
public InnerError InnerError { get; set; }
public Error(string message, string code, InnerError inner)
{
this.Message = message;
this.Code = code;
this.InnerError = inner;
}
}
public class InnerError
{
public string RequestId { get; set; }
public string Date { get; set; }
public InnerError(string reqId, string reqDate)
{
this.RequestId = reqId;
this.Date = reqDate;
}
}
然后我们可以通过如下代码进行引发我们错误
throw new ApiException(
new Error("An error blah.", "InvalidRange",
new InnerError("12345678", DateTime.Now.ToShortDateString())
));
输出格式如下所示
{
"isError": true,
"error": {
"message": "An error blah.",
"code": "InvalidRange",
"innerError": {
"requestId": "12345678",
"date": "10/16/2019"
}
}
}
使用自定义API响应格式
如果映射满足不了我们的需求。并且我们需要向API响应模型中添加其他属性，那么我们现在可以自定义自己的格式类，通过设置UseCustomSchema为true来实现，代码如下所示
app.UseApiResponseAndExceptionWrapper(new AutoWrapperOptions { UseCustomSchema = true });
现在假设我们想在主API中响应中包含一个属性SentDate和Pagination对象，我们可能希望将API响应模型定义为以下格式
public class MyCustomApiResponse
{
public int Code { get; set; }
public string Message { get; set; }
public object Payload { get; set; }
public DateTime SentDate { get; set; }
public Pagination Pagination { get; set; }
public MyCustomApiResponse(DateTime sentDate, object payload = null, string message = "", int statusCode = 200, Pagination pagination = null)
{
this.Code = statusCode;
this.Message = message == string.Empty ? "Success" : message;
this.Payload = payload;
this.SentDate = sentDate;
this.Pagination = pagination;
}
public MyCustomApiResponse(DateTime sentDate, object payload = null, Pagination pagination = null)
{
this.Code = 200;
this.Message = "Success";
this.Payload = payload;
this.SentDate = sentDate;
this.Pagination = pagination;
}
public MyCustomApiResponse(object payload)
{
this.Code = 200;
this.Payload = payload;
}
}
public class Pagination
{
public int TotalItemsCount { get; set; }
public int PageSize { get; set; }
public int CurrentPage { get; set; }
public int TotalPages { get; set; }
}
通过如下代码片段进行测试结果
public async Task<MyCustomApiResponse> Get()
{
var data = await _personManager.GetAllAsync();
return new MyCustomApiResponse(DateTime.UtcNow, data,
new Pagination
{
CurrentPage = 1,
PageSize = 10,
TotalItemsCount = 200,
TotalPages = 20
});
}
运行后会得到如下影响格式
{
"code": 200,
"message": "Success",
"payload": [
{
"id": 1,
"firstName": "Vianne",
"lastName": "Durano",
"dateOfBirth": "2018-11-01T00:00:00"
},
{
"id": 2,
"firstName": "Vynn",
"lastName": "Durano",
"dateOfBirth": "2018-11-01T00:00:00"
},
{
"id": 3,
"firstName": "Mitch",
"lastName": "Durano",
"dateOfBirth": "2018-11-01T00:00:00"
}
],
"sentDate": "2019-10-17T02:26:32.5242353Z",
"pagination": {
"totalItemsCount": 200,
"pageSize": 10,
"currentPage": 1,
"totalPages": 20
}
}
但是从这里要注意一旦我们对API响应进行自定义，那么就代表我们完全控制了要格式化数据的方式，同时丢失了默认API响应的某些选项配置。但是我们仍然可以利用ApiException()方法引发用户定义的错误消息
如下所示
[Route("{id:long}")]
[HttpPut]
public async Task<MyCustomApiResponse> Put(long id, [FromBody] PersonDTO dto)
{
if (ModelState.IsValid)
{
try
{
var person = _mapper.Map<Person>(dto);
person.ID = id;
if (await _personManager.UpdateAsync(person))
return new MyCustomApiResponse(DateTime.UtcNow, true, "Update successful.");
else
throw new ApiException($"Record with id: {id} does not exist.", 400);
}
catch (Exception ex)
{
_logger.Log(LogLevel.Error, ex, "Error when trying to update with ID:{@ID}", id);
throw;
}
}
else
throw new ApiException(ModelState.AllErrors());
}
现在当进行模型验证时，可以获得默认响应格式
{
"isError": true,
"responseException": {
"exceptionMessage": "Request responded with validation error(s). Please correct the specified validation errors and try again.",
"validationErrors": [
{
"field": "FirstName",
"message": "'First Name' must not be empty."
}
]
}
}