从零开始搭建.NET Core 2.0 API(学习笔记一)
一、 VS 2017 新建一个项目 选择ASP.NET Core Web应用程序，再选择Web API,选择ASP.NET Core 2.0版本
二、 添加API帮助页面 API项目添加 NuGet NSwag.AspNetCore 引用， 然后在添加NSwag设置
运行项目 http://localhost:prot/swagger 即可打开帮助页。
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
app.UseBrowserLink();
}
else
{
app.UseExceptionHandler("/Home/Error");
}
app.UseStaticFiles();
app.UseSwaggerUi(typeof(Startup).GetTypeInfo().Assembly, settings =>
{
settings.GeneratorSettings.DefaultPropertyNameHandling = PropertyNameHandling.CamelCase;
});
app.UseMvc(route =>
{
route.MapRoute(name: "default", template: "{controller=Home}/{action=Get}/{id?}");
});
}
三、 Startup 类ConfigureServices方法中，添加配置中心初始化；配置中心统一管理配置，便于维护
public IServiceProvider ConfigureServices(IServiceCollection services)
{
ConfigHelper.Init(Configuration["ConfigZookeeperAddress"], Configuration["ConfigNodePath"]);
services.AddSingleton<ILogWrite, LogWrite>(); services.AddMvc(options =>
{
options.Filters.Add<AuthorizationFilter>();
options.Filters.Add<ExceptionFilter>();
options.Filters.Add<PerformanceLogFilter>();
}); var builder = new ContainerBuilder();//实例化 AutoFac 容器
builder.Populate(services); // TODO: 这里添加其他需要注入类的注册 ApplicationContainer = builder.Build();
return new AutofacServiceProvider(ApplicationContainer);
}
四、添加一个基础设置项目，添加一个日志接口 ILogWrite,一个记录日志实现类 LogWrite 在Startup 类ConfigureServices方法中添加日志 Ioc
因为日志拦截器和异常拦截器会用到日志记录需要注入 所以日志在AddMvc()前面添加，Autofac配置不能在 AddMvc前面，所以这里用.NET Core的Ioc容器，后面Autofac会接管容器。
services.AddSingleton<ILogWrite, LogWrite>();
五、filter 添加三个类分别是
a AuthorizationFilter 权限过滤器
b ExceptionFilter 异常过滤器
c PerformanceLogFilter 性能日志过滤器
ExceptionFilter 、PerformanceLogFilter 分别定义构造函数，注入日志依赖。
public ExceptionFilter(ILogWrite logWrite)
{
_logWrite = logWrite;
} public PerformanceLogFilter(ILogWrite logWrite)
{
_logWrite = logWrite;
}
过滤器必须添加在 Startup类ConfigureServices的services.AddMvc()中
services.AddMvc(options =>
{
options.Filters.Add<AuthorizationFilter>();
options.Filters.Add<ExceptionFilter>();
options.Filters.Add<PerformanceLogFilter>();
});
六、Action参数读取，为了在异常过滤器、性能日志过滤器中，读取参数需要在权限过滤器中添加下面两行代码
public class AuthorizationFilter : IAuthorizationFilter
{
public void OnAuthorization(AuthorizationFilterContext context)
{
HttpRequest request = context.HttpContext.Request;
request.EnableRewind();
request.Body.Position = 0;
}
}
七、性能日志过滤器 PerformanceLogFilter 继承 IActionFilter，实现两个接口
OnActionExecuting 在调用操作方法之前发生
OnActionExecuted 在调用操作方法之后发生
a 在方法 OnActionExecuting中 实例化一个 Stopwatch 用于记录方法开支执行时间
把Stopwatch 实力加入 HttpContext.Items 中，便于在 OnActionExecuted 获取。
b 读取Action请求参数, 放入 HttpContext.Items 中, 不知道为什么OnActionExecuted 去不到参数
/// <summary>
/// 在调用操作方法之前发生。
/// </summary>
/// <param name="context"></param>
public void OnActionExecuting(ActionExecutingContext context)
{
//
if (SkipLogging(context)) return; var watch = new Stopwatch();
context.HttpContext.Items[ConfigHelper.HttpRequestStopWatcher] = watch;
var paramenters = context.ActionArguments.Count==0?string.Empty:context.ActionArguments.Serialize();
context.HttpContext.Items[ConfigHelper.FilterActionArguments] = paramenters;
watch.Start();
}
OnActionExecuting 中增加了性能日志开关，如果关闭直接返回，不创建Stopwatch,
在OnActionExecuted中回去到的Stopwatch是null 则直接返回（也可以用性能日志开关做判断），不处理后续。
如果Controll、Action添加了NoLog特性，则不记录性能日志
private static bool SkipLogging(ActionExecutingContext actionContext)
{
if (!ConfigHelper.IsPerformanceLog) return true;
return actionContext.ActionDescriptor.GetType().GetCustomAttributes(typeof(NoLogAttribute), false).Any() ||
actionContext.Controller.GetType().GetCustomAttributes(typeof(NoLogAttribute), false).Any();
}
/// <summary>
/// 忽略性能日志记录特性
/// </summary>
[AttributeUsage(AttributeTargets.Method | AttributeTargets.Class, Inherited = true)]
public class NoLogAttribute : Attribute
{
}
八、异常过滤器
/// <summary>
/// 异常拦截器
/// </summary>
public class ExceptionFilter : IExceptionFilter
{
ILogWrite _logWrite;
public ExceptionFilter(ILogWrite logWrite)
{
_logWrite = logWrite;
} /// <summary>
///
/// </summary>
/// <param name="actionExecutedContext"></param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public void OnException(ExceptionContext context)
{
BizResult<bool> biz; var paramenters = context.HttpContext.Items[ConfigHelper.FilterActionArguments].ToString();
try
{
biz = new BizResult<bool>(false, (int)B2CBizCode.Exception, context.Exception.Message); if (context.Exception.InnerException != null)
biz.SysMessage += ":" + context.Exception.InnerException.Message; if (ConfigHelper.IsPerformanceLog)
{
var watch = context.HttpContext.Items[ConfigHelper.HttpRequestStopWatcher] as Stopwatch;
watch?.Stop(); var name = context.ActionDescriptor.GetType().GetProperty("ActionName").GetValue(context.ActionDescriptor).ToString(); _logWrite.InfoAsync(new
{
CreateTime = DateTime.Now,
Method = name,
TimeSpan = watch.Elapsed,
IsSuccess = false,
Content = paramenters,
Code = ((B2CBizCode)biz.BusinessCode).ToString(),
Message = biz.BusinessMessage
}.Serialize());
}
}
catch (Exception ex)
{
biz = new BizResult<bool>(false, (int)B2CBizCode.Exception, ex.Message);
}
context.Result = new ApplicationErrorResult(biz); _logWrite?.ErrorAsync($"链接访问出错：{context.HttpContext.Request.Path}", context.HttpContext.Request.Method, this.GetType().Name, context.Exception, paramenters);
return;
}
} public class ApplicationErrorResult : ObjectResult
{
public ApplicationErrorResult(object value) : base(value)
{
StatusCode = (int)HttpStatusCode.InternalServerError;
}
}
九 、添加Autofac，Autofac比.NET Core自带的 Ioc更好用。 NuGetAPI 项目中添加Autofac.Configuration、Autofac.Extensions.DependencyInjection 两个引用 然后 ConfigureServices方法中添加Ioc容器
public IServiceProvider ConfigureServices(IServiceCollection services)
{
ConfigHelper.Init(Configuration["ConfigZookeeperAddress"], Configuration["ConfigNodePath"]);
services.AddSingleton<ILogWrite, LogWrite>(); services.AddMvc(options =>
{
options.Filters.Add<AuthorizationFilter>();
options.Filters.Add<ExceptionFilter>();
options.Filters.Add<PerformanceLogFilter>();
}); var builder = new ContainerBuilder();//实例化 AutoFac 容器
builder.Populate(services); // TODO: 这里添加其他需要注入类的注册 ApplicationContainer = builder.Build();
return new AutofacServiceProvider(ApplicationContainer);
}
至此.NET Core API的 拦截器、配置管理、日志、Ioc 设置已完成。
public IServiceProvider ConfigureServices(IServiceCollection services) { ConfigHelper.Init(Configuration["ConfigZookeeperAddress"], Configuration["ConfigNodePath"]); services.AddSingleton<ILogWrite, LogWrite>();
services.AddMvc(options => { options.Filters.Add<AuthorizationFilter>(); options.Filters.Add<ExceptionFilter>(); options.Filters.Add<PerformanceLogFilter>(); });
var builder = new ContainerBuilder();//实例化 AutoFac 容器 builder.Populate(services);
// TODO: 这里添加其他需要注入类的注册
ApplicationContainer = builder.Build(); return new AutofacServiceProvider(ApplicationContainer); }