前言

在前面的文章中，我們介紹了在業(yè)務(wù)層實(shí)現(xiàn)管道模式：

• 響應(yīng)緩存

• 記錄請(qǐng)求日志

今天，我們同樣使用IPipelineBehavior，介紹如何在業(yè)務(wù)層實(shí)現(xiàn)校驗(yàn)請(qǐng)求參數(shù)，用于檢查輸入是否滿足業(yè)務(wù)要求。

Demo

首先，創(chuàng)建ASP.NET Core Web API項(xiàng)目，引用Nuget包：

MediatR MediatR.Extensions.Microsoft.DependencyInjection FluentValidation FluentValidation.DependencyInjectionExtensions

1.實(shí)現(xiàn)IPipelineBehavior

創(chuàng)建ValidationBehaviour，用于校驗(yàn)請(qǐng)求參數(shù):

public?class?ValidationBehaviour<TRequest,?TResponse>?:?IPipelineBehavior<TRequest,?TResponse>where?TRequest?:?IRequest<TResponse> {private?readonly?IEnumerable<IValidator<TRequest>>?_validators;public?ValidationBehaviour(IEnumerable<IValidator<TRequest>>?validators){_validators?=?validators;}public?async?Task<TResponse>?Handle(TRequest?request,?CancellationToken?cancellationToken,RequestHandlerDelegate<TResponse>?next){//?如果沒(méi)有為當(dāng)前正在執(zhí)行的請(qǐng)求定義校驗(yàn)器，則退出if?(!_validators.Any())?return?await?next();//?執(zhí)行校驗(yàn)器var?context?=?new?ValidationContext<TRequest>(request);var?validationResults?=await?Task.WhenAll(_validators.Select(v?=>?v.ValidateAsync(context,?cancellationToken)));var?errors?=?validationResults.SelectMany(r?=>?r.Errors).Where(f?=>?f?!=?null).ToList();if?(!errors.Any())?return?await?next();//?返回錯(cuò)誤var?sb?=?new?StringBuilder();errors.ForEach(f?=>{sb.Append(f.ErrorMessage);});throw?new?Exception(sb.ToString());} }

2.注冊(cè)IPipelineBehavior

修改Startup.cs：

services.AddValidatorsFromAssembly(typeof(Startup).Assembly);services.AddMediatR(typeof(Startup).Assembly); services.AddTransient(typeof(IPipelineBehavior<,>),?typeof(ValidationBehaviour<,>))

3.測(cè)試

修改WeatherForecastController，使用Mediator：

public?class?WeatherForecastController?:?ControllerBase {private?readonly?IMediator?_mediator;public?WeatherForecastController(IMediator?mediator){this._mediator?=?mediator;}[HttpGet]public?async?Task<IEnumerable<WeatherForecast>>?Get(int?count){return?await?this._mediator.Send(new?GetWeatherForecastQuery?{?Count=?count?});} }public?class?GetWeatherForecastQuery?:?IRequest<IEnumerable<WeatherForecast>> {public?int?Count?{?get;?set;?} }internal?class?GetWeatherForecastQueryHandler?:?IRequestHandler<GetWeatherForecastQuery,?IEnumerable<WeatherForecast>> {?public?async?Task<IEnumerable<WeatherForecast>>?Handle(GetWeatherForecastQuery?request,?CancellationToken?cancellationToken){var?rng?=?new?Random();return?Enumerable.Range(1,?request.Count).Select(index?=>?new?WeatherForecast{TemperatureC?=?rng.Next(-20,?55),}).ToArray();} }

并為GetWeatherForecastQuery創(chuàng)建一個(gè)Validator，校驗(yàn)Count參數(shù)的取值范圍：

public?class?GetWeatherForecastQueryValidator?:?AbstractValidator<GetWeatherForecastQuery> {public?GetWeatherForecastQueryValidator(){RuleFor(c?=>?c.Count).GreaterThanOrEqualTo(1).WithMessage("Count的取值范圍是1到5").LessThanOrEqualTo(5).WithMessage("Count的取值范圍是1到5");} }

運(yùn)行程序，輸入錯(cuò)誤值，將拋出異常：

結(jié)論

在本文中，我們通過(guò)FluentValidation實(shí)現(xiàn)校驗(yàn)功能，詳細(xì)使用方式請(qǐng)參看官網(wǎng)：https://fluentvalidation.net/

如果你覺(jué)得這篇文章對(duì)你有所啟發(fā)，請(qǐng)關(guān)注我的個(gè)人公眾號(hào)”My IO“

總結(jié)

以上是生活随笔為你收集整理的在业务层实现校验请求参数的全部?jī)?nèi)容，希望文章能夠幫你解決所遇到的問(wèn)題。

如果覺(jué)得生活随笔網(wǎng)站內(nèi)容還不錯(cuò)，歡迎將生活随笔推薦給好友。