前端技术
HTML
CSS
Javascript
前端框架和UI库
VUE
ReactJS
AngularJS
JQuery
NodeJS
JSON
Element-UI
Bootstrap
Material UI
服务端和客户端
Java
Python
PHP
Golang
Scala
Kotlin
Groovy
Ruby
Lua
.net
c#
c++
后端WEB和工程框架
SpringBoot
SpringCloud
Struts2
MyBatis
Hibernate
Tornado
Beego
Go-Spring
Go Gin
Go Iris
Dubbo
HessianRPC
Maven
Gradle
数据库
MySQL
Oracle
Mongo
中间件与web容器
Redis
MemCache
Etcd
Cassandra
Kafka
RabbitMQ
RocketMQ
ActiveMQ
Nacos
Consul
Tomcat
Nginx
Netty
大数据技术
Hive
Impala
ClickHouse
DorisDB
Greenplum
PostgreSQL
HBase
Kylin
Hadoop
Apache Pig
ZooKeeper
SeaTunnel
Sqoop
Datax
Flink
Spark
Mahout
数据搜索与日志
ElasticSearch
Apache Lucene
Apache Solr
Kibana
Logstash
数据可视化与OLAP
Apache Atlas
Superset
Saiku
Tesseract
系统与容器
Linux
Shell
Docker
Kubernetes
[微服务架构下的统一用户认证方案]的搜索结果
这里是文章列表。热门标签的颜色随机变换,标签颜色没有特殊含义。
点击某个标签可搜索标签相关的文章。
点击某个标签可搜索标签相关的文章。
转载文章
...02。 该文由互联网用户投稿提供,文中观点代表作者本人意见,并不代表本站的立场。 作为信息平台,本站仅提供文章转载服务,并不拥有其所有权,也不对文章内容的真实性、准确性和合法性承担责任。 如发现本文存在侵权、违法、违规或事实不符的情况,请及时联系我们,我们将第一时间进行核实并删除相应内容。 注:本文是【ASP.NET Identity系列教程】的第三篇。本系列教程详细、完整、深入地介绍了微软的ASP.NET Identity技术,描述了如何运用ASP.NET Identity实现应用程序的用户管理,以及实现应用程序的认证与授权等相关技术,译者希望本系列教程能成为掌握ASP.NET Identity技术的一份完整而有价值的资料。读者若是能够按照文章的描述,一边阅读、一边实践、一边理解,定能有意想不到的巨大收获!希望本系列博文能够得到广大园友的高度推荐。 15 Advanced ASP.NET Identity 15 ASP.NET Identity高级技术 In this chapter, I finish my description of ASP.NET Identity by showing you some of the advanced features it offers. I demonstrate how you can extend the database schema by defining custom properties on the user class and how to use database migrations to apply those properties without deleting the data in the ASP.NET Identity database. I also explain how ASP.NET Identity supports the concept of claims and demonstrates how they can be used to flexibly authorize access to action methods. I finish the chapter—and the book—by showing you how ASP.NET Identity makes it easy to authenticate users through third parties. I demonstrate authentication with Google accounts, but ASP.NET Identity has built-in support for Microsoft, Facebook, and Twitter accounts as well. Table 15-1 summarizes this chapter. 本章将完成对ASP.NET Identity的描述,向你展示它所提供的一些高级特性。我将演示,你可以扩展ASP.NET Identity的数据库架构,其办法是在用户类上定义一些自定义属性。也会演示如何使用数据库迁移,这样可以运用自定义属性,而不必删除ASP.NET Identity数据库中的数据。还会解释ASP.NET Identity如何支持声明(Claims)概念,并演示如何将它们灵活地用来对动作方法进行授权访问。最后向你展示ASP.NET Identity很容易通过第三方部件来认证用户,以此结束本章以及本书。将要演示的是使用Google账号认证,但ASP.NET Identity对于Microsoft、Facebook以及Twitter账号,都有内建的支持。表15-1是本章概要。 Table 15-1. Chapter Summary 表15-1. 本章概要 Problem 问题 Solution 解决方案 Listing 清单号 Store additional information about users. 存储用户的附加信息 Define custom user properties. 定义自定义用户属性 1–3, 8–11 Update the database schema without deleting user data. 更新数据库架构而不删除用户数据 Perform a database migration. 执行数据库迁移 4–7 Perform fine-grained authorization. 执行细粒度授权 Use claims. 使用声明(Claims) 12–14 Add claims about a user. 添加用户的声明(Claims) Use the ClaimsIdentity.AddClaims method. 使用ClaimsIdentity.AddClaims方法 15–19 Authorize access based on claim values. 基于声明(Claims)值授权访问 Create a custom authorization filter attribute. 创建一个自定义的授权过滤器注解属性 20–21 Authenticate through a third party. 通过第三方认证 Install the NuGet package for the authentication provider, redirect requests to that provider, and specify a callback URL that creates the user account. 安装认证提供器的NuGet包,将请求重定向到该提供器,并指定一个创建用户账号的回调URL。 22–25 15.1 Preparing the Example Project 15.1 准备示例项目 In this chapter, I am going to continue working on the Users project I created in Chapter 13 and enhanced in Chapter 14. No changes to the application are required, but start the application and make sure that there are users in the database. Figure 15-1 shows the state of my database, which contains the users Admin, Alice, Bob, and Joe from the previous chapter. To check the users, start the application and request the /Admin/Index URL and authenticate as the Admin user. 本章打算继续使用第13章创建并在第14章增强的Users项目。对应用程序无需做什么改变,但需要启动应用程序,并确保数据库中有一些用户。图15-1显示了数据库的状态,它含有上一章的用户Admin、Alice、Bob以及Joe。为了检查用户,请启动应用程序,请求/Admin/Index URL,并以Admin用户进行认证。 Figure 15-1. The initial users in the Identity database 图15-1. Identity数据库中的最初用户 I also need some roles for this chapter. I used the RoleAdmin controller to create roles called Users and Employees and assigned the users to those roles, as described in Table 15-2. 本章还需要一些角色。我用RoleAdmin控制器创建了角色Users和Employees,并为这些角色指定了一些用户,如表15-2所示。 Table 15-2. The Types of Web Forms Code Nuggets 表15-2. 角色及成员(作者将此表的标题写错了——译者注) Role 角色 Members 成员 Users Alice, Joe Employees Alice, Bob Figure 15-2 shows the required role configuration displayed by the RoleAdmin controller. 图15-2显示了由RoleAdmin控制器所显示出来的必要的角色配置。 Figure 15-2. Configuring the roles required for this chapter 图15-2. 配置本章所需的角色 15.2 Adding Custom User Properties 15.2 添加自定义用户属性 When I created the AppUser class to represent users in Chapter 13, I noted that the base class defined a basic set of properties to describe the user, such as e-mail address and telephone number. Most applications need to store more information about users, including persistent application preferences and details such as addresses—in short, any data that is useful to running the application and that should last between sessions. In ASP.NET Membership, this was handled through the user profile system, but ASP.NET Identity takes a different approach. 我在第13章创建AppUser类来表示用户时曾做过说明,基类定义了一组描述用户的基本属性,如E-mail地址、电话号码等。大多数应用程序还需要存储用户的更多信息,包括持久化应用程序爱好以及地址等细节——简言之,需要存储对运行应用程序有用并且在各次会话之间应当保持的任何数据。在ASP.NET Membership中,这是通过用户资料(User Profile)系统来处理的,但ASP.NET Identity采取了一种不同的办法。 Because the ASP.NET Identity system uses Entity Framework to store its data by default, defining additional user information is just a matter of adding properties to the user class and letting the Code First feature create the database schema required to store them. Table 15-3 puts custom user properties in context. 因为ASP.NET Identity默认是使用Entity Framework来存储其数据的,定义附加的用户信息只不过是给用户类添加属性的事情,然后让Code First特性去创建需要存储它们的数据库架构即可。表15-3描述了自定义用户属性的情形。 Table 15-3. Putting Cusotm User Properties in Context 表15-3. 自定义用户属性的情形 Question 问题 Answer 回答 What is it? 什么是自定义用户属性? Custom user properties allow you to store additional information about your users, including their preferences and settings. 自定义用户属性让你能够存储附加的用户信息,包括他们的爱好和设置。 Why should I care? 为何要关心它? A persistent store of settings means that the user doesn’t have to provide the same information each time they log in to the application. 设置的持久化存储意味着,用户不必每次登录到应用程序时都提供同样的信息。 How is it used by the MVC framework? 在MVC框架中如何使用它? This feature isn’t used directly by the MVC framework, but it is available for use in action methods. 此特性不是由MVC框架直接使用的,但它在动作方法中使用是有效的。 15.2.1 Defining Custom Properties 15.2.1 定义自定义属性 Listing 15-1 shows how I added a simple property to the AppUser class to represent the city in which the user lives. 清单15-1演示了如何给AppUser类添加一个简单的属性,用以表示用户生活的城市。 Listing 15-1. Adding a Property in the AppUser.cs File 清单15-1. 在AppUser.cs文件中添加属性 using System;using Microsoft.AspNet.Identity.EntityFramework;namespace Users.Models { public enum Cities {LONDON, PARIS, CHICAGO}public class AppUser : IdentityUser {public Cities City { get; set; } }} I have defined an enumeration called Cities that defines values for some large cities and added a property called City to the AppUser class. To allow the user to view and edit their City property, I added actions to the Home controller, as shown in Listing 15-2. 这里定义了一个枚举,名称为Cities,它定义了一些大城市的值,另外给AppUser类添加了一个名称为City的属性。为了让用户能够查看和编辑City属性,给Home控制器添加了几个动作方法,如清单15-2所示。 Listing 15-2. Adding Support for Custom User Properties in the HomeController.cs File 清单15-2. 在HomeController.cs文件中添加对自定义属性的支持 using System.Web.Mvc;using System.Collections.Generic;using System.Web;using System.Security.Principal;using System.Threading.Tasks;using Users.Infrastructure;using Microsoft.AspNet.Identity;using Microsoft.AspNet.Identity.Owin;using Users.Models;namespace Users.Controllers {public class HomeController : Controller {[Authorize]public ActionResult Index() {return View(GetData("Index"));}[Authorize(Roles = "Users")]public ActionResult OtherAction() {return View("Index", GetData("OtherAction"));}private Dictionary<string, object> GetData(string actionName) {Dictionary<string, object> dict= new Dictionary<string, object>();dict.Add("Action", actionName);dict.Add("User", HttpContext.User.Identity.Name);dict.Add("Authenticated", HttpContext.User.Identity.IsAuthenticated);dict.Add("Auth Type", HttpContext.User.Identity.AuthenticationType);dict.Add("In Users Role", HttpContext.User.IsInRole("Users"));return dict;} [Authorize]public ActionResult UserProps() {return View(CurrentUser);}[Authorize][HttpPost]public async Task<ActionResult> UserProps(Cities city) {AppUser user = CurrentUser;user.City = city;await UserManager.UpdateAsync(user);return View(user);}private AppUser CurrentUser {get {return UserManager.FindByName(HttpContext.User.Identity.Name);} }private AppUserManager UserManager {get {return HttpContext.GetOwinContext().GetUserManager<AppUserManager>();} }} } I added a CurrentUser property that uses the AppUserManager class to retrieve an AppUser instance to represent the current user. I pass the AppUser object as the view model object in the GET version of the UserProps action method, and the POST method uses it to update the value of the new City property. Listing 15-3 shows the UserProps.cshtml view, which displays the City property value and contains a form to change it. 我添加了一个CurrentUser属性,它使用AppUserManager类接收了表示当前用户的AppUser实例。在GET版本的UserProps动作方法中,传递了这个AppUser对象作为视图模型。而在POST版的方法中用它更新了City属性的值。清单15-3显示了UserProps.cshtml视图,它显示了City属性的值,并包含一个修改它的表单。 Listing 15-3. The Contents of the UserProps.cshtml File in the Views/Home Folder 清单15-3. Views/Home文件夹中UserProps.cshtml文件的内容 @using Users.Models@model AppUser@{ ViewBag.Title = "UserProps";}<div class="panel panel-primary"><div class="panel-heading">Custom User Properties</div><table class="table table-striped"><tr><th>City</th><td>@Model.City</td></tr></table></div> @using (Html.BeginForm()) {<div class="form-group"><label>City</label>@Html.DropDownListFor(x => x.City, new SelectList(Enum.GetNames(typeof(Cities))))</div><button class="btn btn-primary" type="submit">Save</button>} Caution Don’t start the application when you have created the view. In the sections that follow, I demonstrate how to preserve the contents of the database, and if you start the application now, the ASP.NET Identity users will be deleted. 警告:创建了视图之后不要启动应用程序。在以下小节中,将演示如何保留数据库的内容,如果现在启动应用程序,将会删除ASP.NET Identity的用户。 15.2.2 Preparing for Database Migration 15.2.2 准备数据库迁移 The default behavior for the Entity Framework Code First feature is to drop the tables in the database and re-create them whenever classes that drive the schema have changed. You saw this in Chapter 14 when I added support for roles: When the application was started, the database was reset, and the user accounts were lost. Entity Framework Code First特性的默认行为是,一旦修改了派生数据库架构的类,便会删除数据库中的数据表,并重新创建它们。在第14章可以看到这种情况,在我添加角色支持时:当重启应用程序后,数据库被重置,用户账号也丢失。 Don’t start the application yet, but if you were to do so, you would see a similar effect. Deleting data during development is usually not a problem, but doing so in a production setting is usually disastrous because it deletes all of the real user accounts and causes a panic while the backups are restored. In this section, I am going to demonstrate how to use the database migration feature, which updates a Code First schema in a less brutal manner and preserves the existing data it contains. 不要启动应用程序,但如果你这么做了,会看到类似的效果。在开发期间删除数据没什么问题,但如果在产品设置中这么做了,通常是灾难性的,因为它会删除所有真实的用户账号,而备份恢复是很痛苦的事。在本小节中,我打算演示如何使用数据库迁移特性,它能以比较温和的方式更新Code First的架构,并保留架构中的已有数据。 The first step is to issue the following command in the Visual Studio Package Manager Console: 第一个步骤是在Visual Studio的“Package Manager Console(包管理器控制台)”中发布以下命令: Enable-Migrations –EnableAutomaticMigrations This enables the database migration support and creates a Migrations folder in the Solution Explorer that contains a Configuration.cs class file, the contents of which are shown in Listing 15-4. 它启用了数据库的迁移支持,并在“Solution Explorer(解决方案资源管理器)”创建一个Migrations文件夹,其中含有一个Configuration.cs类文件,内容如清单15-4所示。 Listing 15-4. The Contents of the Configuration.cs File 清单15-4. Configuration.cs文件的内容 namespace Users.Migrations {using System;using System.Data.Entity;using System.Data.Entity.Migrations;using System.Linq;internal sealed class Configuration: DbMigrationsConfiguration<Users.Infrastructure.AppIdentityDbContext> {public Configuration() {AutomaticMigrationsEnabled = true;ContextKey = "Users.Infrastructure.AppIdentityDbContext";}protected override void Seed(Users.Infrastructure.AppIdentityDbContext context) {// This method will be called after migrating to the latest version.// 此方法将在迁移到最新版本时调用// You can use the DbSet<T>.AddOrUpdate() helper extension method// to avoid creating duplicate seed data. E.g.// 例如,你可以使用DbSet<T>.AddOrUpdate()辅助器方法来避免创建重复的种子数据//// context.People.AddOrUpdate(// p => p.FullName,// new Person { FullName = "Andrew Peters" },// new Person { FullName = "Brice Lambson" },// new Person { FullName = "Rowan Miller" }// );//} }} Tip You might be wondering why you are entering a database migration command into the console used to manage NuGet packages. The answer is that the Package Manager Console is really PowerShell, which is a general-purpose tool that is mislabeled by Visual Studio. You can use the console to issue a wide range of helpful commands. See http://go.microsoft.com/fwlink/?LinkID=108518 for details. 提示:你可能会觉得奇怪,为什么要在管理NuGet包的控制台中输入数据库迁移的命令?答案是“Package Manager Console(包管理控制台)”是真正的PowerShell,这是Visual studio冒用的一个通用工具。你可以使用此控制台发送大量的有用命令,详见http://go.microsoft.com/fwlink/?LinkID=108518。 The class will be used to migrate existing content in the database to the new schema, and the Seed method will be called to provide an opportunity to update the existing database records. In Listing 15-5, you can see how I have used the Seed method to set a default value for the new City property I added to the AppUser class. (I have also updated the class file to reflect my usual coding style.) 这个类将用于把数据库中的现有内容迁移到新的数据库架构,Seed方法的调用为更新现有数据库记录提供了机会。在清单15-5中可以看到,我如何用Seed方法为新的City属性设置默认值,City是添加到AppUser类中自定义属性。(为了体现我一贯的编码风格,我对这个类文件也进行了更新。) Listing 15-5. Managing Existing Content in the Configuration.cs File 清单15-5. 在Configuration.cs文件中管理已有内容 using System.Data.Entity.Migrations;using Microsoft.AspNet.Identity;using Microsoft.AspNet.Identity.EntityFramework;using Users.Infrastructure;using Users.Models;namespace Users.Migrations {internal sealed class Configuration: DbMigrationsConfiguration<AppIdentityDbContext> {public Configuration() {AutomaticMigrationsEnabled = true;ContextKey = "Users.Infrastructure.AppIdentityDbContext";}protected override void Seed(AppIdentityDbContext context) {AppUserManager userMgr = new AppUserManager(new UserStore<AppUser>(context));AppRoleManager roleMgr = new AppRoleManager(new RoleStore<AppRole>(context)); string roleName = "Administrators";string userName = "Admin";string password = "MySecret";string email = "admin@example.com";if (!roleMgr.RoleExists(roleName)) {roleMgr.Create(new AppRole(roleName));}AppUser user = userMgr.FindByName(userName);if (user == null) {userMgr.Create(new AppUser { UserName = userName, Email = email },password);user = userMgr.FindByName(userName);}if (!userMgr.IsInRole(user.Id, roleName)) {userMgr.AddToRole(user.Id, roleName);}foreach (AppUser dbUser in userMgr.Users) {dbUser.City = Cities.PARIS;}context.SaveChanges();} }} You will notice that much of the code that I added to the Seed method is taken from the IdentityDbInit class, which I used to seed the database with an administration user in Chapter 14. This is because the new Configuration class added to support database migrations will replace the seeding function of the IdentityDbInit class, which I’ll update shortly. Aside from ensuring that there is an admin user, the statements in the Seed method that are important are the ones that set the initial value for the City property I added to the AppUser class, as follows: 你可能会注意到,添加到Seed方法中的许多代码取自于IdentityDbInit类,在第14章中我用这个类将管理用户植入了数据库。这是因为这个新添加的、用以支持数据库迁移的Configuration类,将代替IdentityDbInit类的种植功能,我很快便会更新这个类。除了要确保有admin用户之外,在Seed方法中的重要语句是那些为AppUser类的City属性设置初值的语句,如下所示: ...foreach (AppUser dbUser in userMgr.Users) { dbUser.City = Cities.PARIS;}context.SaveChanges();... You don’t have to set a default value for new properties—I just wanted to demonstrate that the Seed method in the Configuration class can be used to update the existing user records in the database. 你不一定要为新属性设置默认值——这里只是想演示Configuration类中的Seed方法,可以用它更新数据库中的已有用户记录。 Caution Be careful when setting values for properties in the Seed method for real projects because the values will be applied every time you change the schema, overriding any values that the user has set since the last schema update was performed. I set the value of the City property just to demonstrate that it can be done. 警告:在用于真实项目的Seed方法中为属性设置值时要小心,因为你每一次修改架构时,都会运用这些值,这会将自执行上一次架构更新之后,用户设置的任何数据覆盖掉。这里设置City属性的值只是为了演示它能够这么做。 Changing the Database Context Class 修改数据库上下文类 The reason that I added the seeding code to the Configuration class is that I need to change the IdentityDbInit class. At present, the IdentityDbInit class is derived from the descriptively named DropCreateDatabaseIfModelChanges<AppIdentityDbContext> class, which, as you might imagine, drops the entire database when the Code First classes change. Listing 15-6 shows the changes I made to the IdentityDbInit class to prevent it from affecting the database. 在Configuration类中添加种植代码的原因是我需要修改IdentityDbInit类。此时,IdentityDbInit类派生于描述性命名的DropCreateDatabaseIfModelChanges<AppIdentityDbContext> 类,和你相像的一样,它会在Code First类改变时删除整个数据库。清单15-6显示了我对IdentityDbInit类所做的修改,以防止它影响数据库。 Listing 15-6. Preventing Database Schema Changes in the AppIdentityDbContext.cs File 清单15-6. 在AppIdentityDbContext.cs文件是阻止数据库架构变化 using System.Data.Entity;using Microsoft.AspNet.Identity.EntityFramework;using Users.Models;using Microsoft.AspNet.Identity; namespace Users.Infrastructure {public class AppIdentityDbContext : IdentityDbContext<AppUser> {public AppIdentityDbContext() : base("IdentityDb") { }static AppIdentityDbContext() {Database.SetInitializer<AppIdentityDbContext>(new IdentityDbInit());}public static AppIdentityDbContext Create() {return new AppIdentityDbContext();} } public class IdentityDbInit : NullDatabaseInitializer<AppIdentityDbContext> {} } I have removed the methods defined by the class and changed its base to NullDatabaseInitializer<AppIdentityDbContext> , which prevents the schema from being altered. 我删除了这个类中所定义的方法,并将它的基类改为NullDatabaseInitializer<AppIdentityDbContext> ,它可以防止架构修改。 15.2.3 Performing the Migration 15.2.3 执行迁移 All that remains is to generate and apply the migration. First, run the following command in the Package Manager Console: 剩下的事情只是生成并运用迁移了。首先,在“Package Manager Console(包管理器控制台)”中执行以下命令: Add-Migration CityProperty This creates a new migration called CityProperty (I like my migration names to reflect the changes I made). A class new file will be added to the Migrations folder, and its name reflects the time at which the command was run and the name of the migration. My file is called 201402262244036_CityProperty.cs, for example. The contents of this file contain the details of how Entity Framework will change the database during the migration, as shown in Listing 15-7. 这创建了一个名称为CityProperty的新迁移(我比较喜欢让迁移的名称反映出我所做的修改)。这会在文件夹中添加一个新的类文件,而且其命名会反映出该命令执行的时间以及迁移名称,例如,我的这个文件名称为201402262244036_CityProperty.cs。该文件的内容含有迁移期间Entity Framework修改数据库的细节,如清单15-7所示。 Listing 15-7. The Contents of the 201402262244036_CityProperty.cs File 清单15-7. 201402262244036_CityProperty.cs文件的内容 namespace Users.Migrations {using System;using System.Data.Entity.Migrations; public partial class Init : DbMigration {public override void Up() {AddColumn("dbo.AspNetUsers", "City", c => c.Int(nullable: false));}public override void Down() {DropColumn("dbo.AspNetUsers", "City");} }} The Up method describes the changes that have to be made to the schema when the database is upgraded, which in this case means adding a City column to the AspNetUsers table, which is the one that is used to store user records in the ASP.NET Identity database. Up方法描述了在数据库升级时,需要对架构所做的修改,在这个例子中,意味着要在AspNetUsers数据表中添加City数据列,该数据表是ASP.NET Identity数据库用来存储用户记录的。 The final step is to perform the migration. Without starting the application, run the following command in the Package Manager Console: 最后一步是执行迁移。无需启动应用程序,只需在“Package Manager Console(包管理器控制台)”中运行以下命令即可: Update-Database –TargetMigration CityProperty The database schema will be modified, and the code in the Configuration.Seed method will be executed. The existing user accounts will have been preserved and enhanced with a City property (which I set to Paris in the Seed method). 这会修改数据库架构,并执行Configuration.Seed方法中的代码。已有用户账号会被保留,且增强了City属性(我在Seed方法中已将其设置为“Paris”)。 15.2.4 Testing the Migration 15.2.4 测试迁移 To test the effect of the migration, start the application, navigate to the /Home/UserProps URL, and authenticate as one of the Identity users (for example, as Alice with the password MySecret). Once authenticated, you will see the current value of the City property for the user and have the opportunity to change it, as shown in Figure 15-3. 为了测试迁移的效果,启动应用程序,导航到/Home/UserProps URL,并以Identity中的用户(例如Alice,口令MySecret)进行认证。一旦已被认证,便会看到该用户City属性的当前值,并可以对其进行修改,如图15-3所示。 Figure 15-3. Displaying and changing a custom user property 图15-3. 显示和个性自定义用户属性 15.2.5 Defining an Additional Property 15.2.5 定义附加属性 Now that database migrations are set up, I am going to define a further property just to demonstrate how subsequent changes are handled and to show a more useful (and less dangerous) example of using the Configuration.Seed method. Listing 15-8 shows how I added a Country property to the AppUser class. 现在,已经建立了数据库迁移,我打算再定义一个属性,这恰恰演示了如何处理持续不断的修改,也为了演示Configuration.Seed方法更有用(至少无害)的示例。清单15-8显示了我在AppUser类上添加了一个Country属性。 Listing 15-8. Adding Another Property in the AppUserModels.cs File 清单15-8. 在AppUserModels.cs文件中添加另一个属性 using System;using Microsoft.AspNet.Identity.EntityFramework; namespace Users.Models {public enum Cities {LONDON, PARIS, CHICAGO} public enum Countries {NONE, UK, FRANCE, USA}public class AppUser : IdentityUser {public Cities City { get; set; }public Countries Country { get; set; }public void SetCountryFromCity(Cities city) {switch (city) {case Cities.LONDON:Country = Countries.UK;break;case Cities.PARIS:Country = Countries.FRANCE;break;case Cities.CHICAGO:Country = Countries.USA;break;default:Country = Countries.NONE;break;} }} } I have added an enumeration to define the country names and a helper method that selects a country value based on the City property. Listing 15-9 shows the change I made to the Configuration class so that the Seed method sets the Country property based on the City, but only if the value of Country is NONE (which it will be for all users when the database is migrated because the Entity Framework sets enumeration columns to the first value). 我已经添加了一个枚举,它定义了国家名称。还添加了一个辅助器方法,它可以根据City属性选择一个国家。清单15-9显示了对Configuration类所做的修改,以使Seed方法根据City设置Country属性,但只当Country为NONE时才进行设置(在迁移数据库时,所有用户都是NONE,因为Entity Framework会将枚举列设置为枚举的第一个值)。 Listing 15-9. Modifying the Database Seed in the Configuration.cs File 清单15-9. 在Configuration.cs文件中修改数据库种子 using System.Data.Entity.Migrations;using Microsoft.AspNet.Identity;using Microsoft.AspNet.Identity.EntityFramework;using Users.Infrastructure;using Users.Models; namespace Users.Migrations {internal sealed class Configuration: DbMigrationsConfiguration<AppIdentityDbContext> {public Configuration() {AutomaticMigrationsEnabled = true;ContextKey = "Users.Infrastructure.AppIdentityDbContext";}protected override void Seed(AppIdentityDbContext context) {AppUserManager userMgr = new AppUserManager(new UserStore<AppUser>(context));AppRoleManager roleMgr = new AppRoleManager(new RoleStore<AppRole>(context)); string roleName = "Administrators";string userName = "Admin";string password = "MySecret";string email = "admin@example.com";if (!roleMgr.RoleExists(roleName)) {roleMgr.Create(new AppRole(roleName));}AppUser user = userMgr.FindByName(userName);if (user == null) {userMgr.Create(new AppUser { UserName = userName, Email = email },password);user = userMgr.FindByName(userName);}if (!userMgr.IsInRole(user.Id, roleName)) {userMgr.AddToRole(user.Id, roleName);} foreach (AppUser dbUser in userMgr.Users) {if (dbUser.Country == Countries.NONE) {dbUser.SetCountryFromCity(dbUser.City);} }context.SaveChanges();} }} This kind of seeding is more useful in a real project because it will set a value for the Country property only if one has not already been set—subsequent migrations won’t be affected, and user selections won’t be lost. 这种种植在实际项目中会更有用,因为它只会在Country属性未设置时,才会设置Country属性的值——后继的迁移不会受到影响,因此不会失去用户的选择。 1. Adding Application Support 1. 添加应用程序支持 There is no point defining additional user properties if they are not available in the application, so Listing 15-10 shows the change I made to the Views/Home/UserProps.cshtml file to display the value of the Country property. 应用程序中如果没有定义附加属性的地方,则附加属性就无法使用了,因此,清单15-10显示了我对Views/Home/UserProps.cshtml文件的修改,以显示Country属性的值。 Listing 15-10. Displaying an Additional Property in the UserProps.cshtml File 清单15-10. 在UserProps.cshtml文件中显示附加属性 @using Users.Models@model AppUser@{ ViewBag.Title = "UserProps";} <div class="panel panel-primary"><div class="panel-heading">Custom User Properties</div><table class="table table-striped"><tr><th>City</th><td>@Model.City</td></tr> <tr><th>Country</th><td>@Model.Country</td></tr></table></div>@using (Html.BeginForm()) {<div class="form-group"><label>City</label>@Html.DropDownListFor(x => x.City, new SelectList(Enum.GetNames(typeof(Cities))))</div><button class="btn btn-primary" type="submit">Save</button>} Listing 15-11 shows the corresponding change I made to the Home controller to update the Country property when the City value changes. 为了在City值变化时能够更新Country属性,清单15-11显示了我对Home控制器所做的相应修改。 Listing 15-11. Setting Custom Properties in the HomeController.cs File 清单15-11. 在HomeController.cs文件中设置自定义属性 using System.Web.Mvc;using System.Collections.Generic;using System.Web;using System.Security.Principal;using System.Threading.Tasks;using Users.Infrastructure;using Microsoft.AspNet.Identity;using Microsoft.AspNet.Identity.Owin;using Users.Models; namespace Users.Controllers {public class HomeController : Controller {// ...other action methods omitted for brevity...// ...出于简化,这里忽略了其他动作方法... [Authorize]public ActionResult UserProps() {return View(CurrentUser);}[Authorize][HttpPost]public async Task<ActionResult> UserProps(Cities city) {AppUser user = CurrentUser;user.City = city;user.SetCountryFromCity(city);await UserManager.UpdateAsync(user);return View(user);}// ...properties omitted for brevity...// ...出于简化,这里忽略了一些属性...} } 2. Performing the Migration 2. 准备迁移 All that remains is to create and apply a new migration. Enter the following command into the Package Manager Console: 剩下的事情就是创建和运用新的迁移了。在“Package Manager Console(包管理器控制台)”中输入以下命令: Add-Migration CountryProperty This will generate another file in the Migrations folder that contains the instruction to add the Country column. To apply the migration, execute the following command: 这将在Migrations文件夹中生成另一个文件,它含有添加Country数据表列的指令。为了运用迁移,可执行以下命令: Update-Database –TargetMigration CountryProperty The migration will be performed, and the value of the Country property will be set based on the value of the existing City property for each user. You can check the new user property by starting the application and authenticating and navigating to the /Home/UserProps URL, as shown in Figure 15-4. 这将执行迁移,Country属性的值将根据每个用户当前的City属性进行设置。通过启动应用程序,认证并导航到/Home/UserProps URL,便可以查看新的用户属性,如图15-4所示。 Figure 15-4. Creating an additional user property 图15-4. 创建附加用户属性 Tip Although I am focused on the process of upgrading the database, you can also migrate back to a previous version by specifying an earlier migration. Use the –Force argument make changes that cause data loss, such as removing a column. 提示:虽然我们关注了升级数据库的过程,但你也可以回退到以前的版本,只需指定一个早期的迁移即可。使用-Force参数进行修改,会引起数据丢失,例如删除数据表列。 15.3 Working with Claims 15.3 使用声明(Claims) In older user-management systems, such as ASP.NET Membership, the application was assumed to be the authoritative source of all information about the user, essentially treating the application as a closed world and trusting the data that is contained within it. 在旧的用户管理系统中,例如ASP.NET Membership,应用程序被假设成是用户所有信息的权威来源,本质上将应用程序视为是一个封闭的世界,并且只信任其中所包含的数据。 This is such an ingrained approach to software development that it can be hard to recognize that’s what is happening, but you saw an example of the closed-world technique in Chapter 14 when I authenticated users against the credentials stored in the database and granted access based on the roles associated with those credentials. I did the same thing again in this chapter when I added properties to the user class. Every piece of information that I needed to manage user authentication and authorization came from within my application—and that is a perfectly satisfactory approach for many web applications, which is why I demonstrated these techniques in such depth. 这是软件开发的一种根深蒂固的方法,使人很难认识到这到底意味着什么,第14章你已看到了这种封闭世界技术的例子,根据存储在数据库中的凭据来认证用户,并根据与凭据关联在一起的角色来授权访问。本章前述在用户类上添加属性,也做了同样的事情。我管理用户认证与授权所需的每一个数据片段都来自于我的应用程序——而且这是许多Web应用程序都相当满意的一种方法,这也是我如此深入地演示这些技术的原因。 ASP.NET Identity also supports an alternative approach for dealing with users, which works well when the MVC framework application isn’t the sole source of information about users and which can be used to authorize users in more flexible and fluid ways than traditional roles allow. ASP.NET Identity还支持另一种处理用户的办法,当MVC框架的应用程序不是有关用户的唯一信息源时,这种办法会工作得很好,而且能够比传统的角色授权更为灵活且流畅的方式进行授权。 This alternative approach uses claims, and in this section I’ll describe how ASP.NET Identity supports claims-based authorization. Table 15-4 puts claims in context. 这种可选的办法使用了“Claims(声明)”,因此在本小节中,我将描述ASP.NET Identity如何支持“Claims-Based Authorization(基于声明的授权)”。表15-4描述了声明(Claims)的情形。 提示:“Claim”在英文字典中不完全是“声明”的意思,根据本文的描述,感觉把它说成“声明”也不一定合适,所以在之后的译文中基本都写成中英文并用的形式,即“声明(Claims)”。根据表15-4中的声明(Claims)的定义:声明(Claims)是关于用户的一些信息片段。一个用户的信息片段当然有很多,每一个信息片段就是一项声明(Claim),用户的所有信息片段合起来就是该用户的声明(Claims)。请读者注意该单词的单复数形式——译者注 Table 15-4. Putting Claims in Context 表15-4. 声明(Claims)的情形 Question 问题 Answer 答案 What is it? 什么是声明(Claims)? Claims are pieces of information about users that you can use to make authorization decisions. Claims can be obtained from external systems as well as from the local Identity database. 声明(Claims)是关于用户的一些信息片段,可以用它们做出授权决定。声明(Claims)可以从外部系统获取,也可以从本地的Identity数据库获取。 Why should I care? 为何要关心它? Claims can be used to flexibly authorize access to action methods. Unlike conventional roles, claims allow access to be driven by the information that describes the user. 声明(Claims)可以用来对动作方法进行灵活的授权访问。与传统的角色不同,声明(Claims)让访问能够由描述用户的信息进行驱动。 How is it used by the MVC framework? 如何在MVC框架中使用它? This feature isn’t used directly by the MVC framework, but it is integrated into the standard authorization features, such as the Authorize attribute. 这不是直接由MVC框架使用的特性,但它集成到了标准的授权特性之中,例如Authorize注解属性。 Tip you don’t have to use claims in your applications, and as Chapter 14 showed, ASP.NET Identity is perfectly happy providing an application with the authentication and authorization services without any need to understand claims at all. 提示:你在应用程序中不一定要使用声明(Claims),正如第14章所展示的那样,ASP.NET Identity能够为应用程序提供充分的认证与授权服务,而根本不需要理解声明(Claims)。 15.3.1 Understanding Claims 15.3.1 理解声明(Claims) A claim is a piece of information about the user, along with some information about where the information came from. The easiest way to unpack claims is through some practical demonstrations, without which any discussion becomes too abstract to be truly useful. To get started, I added a Claims controller to the example project, the definition of which you can see in Listing 15-12. 一项声明(Claim)是关于用户的一个信息片段(请注意这个英文单词的单复数形式——译者注),并伴有该片段出自何处的某种信息。揭开声明(Claims)含义最容易的方式是做一些实际演示,任何讨论都会过于抽象根本没有真正的用处。为此,我在示例项目中添加了一个Claims控制器,其定义如清单15-12所示。 Listing 15-12. The Contents of the ClaimsController.cs File 清单15-12. ClaimsController.cs文件的内容 using System.Security.Claims;using System.Web;using System.Web.Mvc; namespace Users.Controllers {public class ClaimsController : Controller {[Authorize]public ActionResult Index() {ClaimsIdentity ident = HttpContext.User.Identity as ClaimsIdentity;if (ident == null) {return View("Error", new string[] { "No claims available" });} else {return View(ident.Claims);} }} } Tip You may feel a little lost as I define the code for this example. Don’t worry about the details for the moment—just stick with it until you see the output from the action method and view that I define. More than anything else, that will help put claims into perspective. 提示:你或许会对我为此例定义的代码感到有点失望。此刻对此细节不必着急——只要稍事忍耐,当看到该动作方法和视图的输出便会明白。尤为重要的是,这有助于洞察声明(Claims)。 You can get the claims associated with a user in different ways. One approach is to use the Claims property defined by the user class, but in this example, I have used the HttpContext.User.Identity property to demonstrate the way that ASP.NET Identity is integrated with the rest of the ASP.NET platform. As I explained in Chapter 13, the HttpContext.User.Identity property returns an implementation of the IIdentity interface, which is a ClaimsIdentity object when working using ASP.NET Identity. The ClaimsIdentity class is defined in the System.Security.Claims namespace, and Table 15-5 shows the members it defines that are relevant to this chapter. 可以通过不同的方式获得与用户相关联的声明(Claims)。方法之一就是使用由用户类定义的Claims属性,但在这个例子中,我使用了HttpContext.User.Identity属性,目的是演示ASP.NET Identity与ASP.NET平台集成的方式(请注意这句话所表示的含义:用户类的Claims属性属于ASP.NET Identity,而HttpContext.User.Identity属性则属于ASP.NET平台。由此可见,ASP.NET Identity已经融合到了ASP.NET平台之中——译者注)。正如第13章所解释的那样,HttpContext.User.Identity属性返回IIdentity的接口实现,当使用ASP.NET Identity时,该实现是一个ClaimsIdentity对象。ClaimsIdentity类是在System.Security.Claims命名空间中定义的,表15-5显示了它所定义的与本章有关的成员。 Table 15-5. The Members Defined by the ClaimsIdentity Class 表15-5. ClaimsIdentity类所定义的成员 Name 名称 Description 描述 Claims Returns an enumeration of Claim objects representing the claims for the user. 返回表示用户声明(Claims)的Claim对象枚举 AddClaim(claim) Adds a claim to the user identity. 给用户添加一个声明(Claim) AddClaims(claims) Adds an enumeration of Claim objects to the user identity. 给用户添加Claim对象的枚举。 HasClaim(predicate) Returns true if the user identity contains a claim that matches the specified predicate. See the “Applying Claims” section for an example predicate. 如果用户含有与指定谓词匹配的声明(Claim)时,返回true。参见“运用声明(Claims)”中的示例谓词 RemoveClaim(claim) Removes a claim from the user identity. 删除用户的声明(Claim)。 Other members are available, but the ones in the table are those that are used most often in web applications, for reason that will become obvious as I demonstrate how claims fit into the wider ASP.NET platform. 还有一些可用的其它成员,但表中的这些是在Web应用程序中最常用的,随着我演示如何将声明(Claims)融入更宽泛的ASP.NET平台,它们为什么最常用就很显然了。 In Listing 15-12, I cast the IIdentity implementation to the ClaimsIdentity type and pass the enumeration of Claim objects returned by the ClaimsIdentity.Claims property to the View method. A Claim object represents a single piece of data about the user, and the Claim class defines the properties shown in Table 15-6. 在清单15-12中,我将IIdentity实现转换成了ClaimsIdentity类型,并且给View方法传递了ClaimsIdentity.Claims属性所返回的Claim对象的枚举。Claim对象所示表示的是关于用户的一个单一的数据片段,Claim类定义的属性如表15-6所示。 Table 15-6. The Properties Defined by the Claim Class 表15-6. Claim类定义的属性 Name 名称 Description 描述 Issuer Returns the name of the system that provided the claim 返回提供声明(Claim)的系统名称 Subject Returns the ClaimsIdentity object for the user who the claim refers to 返回声明(Claim)所指用户的ClaimsIdentity对象 Type Returns the type of information that the claim represents 返回声明(Claim)所表示的信息类型 Value Returns the piece of information that the claim represents 返回声明(Claim)所表示的信息片段 Listing 15-13 shows the contents of the Index.cshtml file that I created in the Views/Claims folder and that is rendered by the Index action of the Claims controller. The view adds a row to a table for each claim about the user. 清单15-13显示了我在Views/Claims文件夹中创建的Index.cshtml文件的内容,它由Claims控制器中的Index动作方法进行渲染。该视图为用户的每项声明(Claim)添加了一个表格行。 Listing 15-13. The Contents of the Index.cshtml File in the Views/Claims Folder 清单15-13. Views/Claims文件夹中Index.cshtml文件的内容 @using System.Security.Claims@using Users.Infrastructure@model IEnumerable<Claim>@{ ViewBag.Title = "Claims"; }<div class="panel panel-primary"><div class="panel-heading">Claims</div><table class="table table-striped"><tr><th>Subject</th><th>Issuer</th><th>Type</th><th>Value</th></tr>@foreach (Claim claim in Model.OrderBy(x => x.Type)) {<tr><td>@claim.Subject.Name</td><td>@claim.Issuer</td><td>@Html.ClaimType(claim.Type)</td><td>@claim.Value</td></tr>}</table></div> The value of the Claim.Type property is a URI for a Microsoft schema, which isn’t especially useful. The popular schemas are used as the values for fields in the System.Security.Claims.ClaimTypes class, so to make the output from the Index.cshtml view easier to read, I added an HTML helper to the IdentityHelpers.cs file, as shown in Listing 15-14. It is this helper that I use in the Index.cshtml file to format the value of the Claim.Type property. Claim.Type属性的值是一个微软模式(Microsoft Schema)的URI(统一资源标识符),这是特别有用的。System.Security.Claims.ClaimTypes类中字段的值使用的是流行模式(Popular Schema),因此为了使Index.cshtml视图的输出更易于阅读,我在IdentityHelpers.cs文件中添加了一个HTML辅助器,如清单15-14所示。Index.cshtml文件正是使用这个辅助器格式化了Claim.Type属性的值。 Listing 15-14. Adding a Helper to the IdentityHelpers.cs File 清单15-14. 在IdentityHelpers.cs文件中添加辅助器 using System.Web;using System.Web.Mvc;using Microsoft.AspNet.Identity.Owin;using System;using System.Linq;using System.Reflection;using System.Security.Claims;namespace Users.Infrastructure {public static class IdentityHelpers {public static MvcHtmlString GetUserName(this HtmlHelper html, string id) {AppUserManager mgr= HttpContext.Current.GetOwinContext().GetUserManager<AppUserManager>();return new MvcHtmlString(mgr.FindByIdAsync(id).Result.UserName);} public static MvcHtmlString ClaimType(this HtmlHelper html, string claimType) {FieldInfo[] fields = typeof(ClaimTypes).GetFields();foreach (FieldInfo field in fields) {if (field.GetValue(null).ToString() == claimType) {return new MvcHtmlString(field.Name);} }return new MvcHtmlString(string.Format("{0}",claimType.Split('/', '.').Last()));} }} Note The helper method isn’t at all efficient because it reflects on the fields of the ClaimType class for each claim that is displayed, but it is sufficient for my purposes in this chapter. You won’t often need to display the claim type in real applications. 注:该辅助器并非十分有效,因为它只是针对每个要显示的声明(Claim)映射出ClaimType类的字段,但对我要的目的已经足够了。在实际项目中不会经常需要显示声明(Claim)的类型。 To see why I have created a controller that uses claims without really explaining what they are, start the application, authenticate as the user Alice (with the password MySecret), and request the /Claims/Index URL. Figure 15-5 shows the content that is generated. 为了弄明白我为何要先创建一个使用声明(Claims)的控制器,而没有真正解释声明(Claims)是什么的原因,可以启动应用程序,以用户Alice进行认证(其口令是MySecret),并请求/Claims/Index URL。图15-5显示了生成的内容。 Figure 15-5. The output from the Index action of the Claims controller 图15-5. Claims控制器中Index动作的输出 It can be hard to make out the detail in the figure, so I have reproduced the content in Table 15-7. 这可能还难以认识到此图的细节,为此我在表15-7中重列了其内容。 Table 15-7. The Data Shown in Figure 15-5 表15-7. 图15-5中显示的数据 Subject(科目) Issuer(发行者) Type(类型) Value(值) Alice LOCAL AUTHORITY SecurityStamp Unique ID Alice LOCAL AUTHORITY IdentityProvider ASP.NET Identity Alice LOCAL AUTHORITY Role Employees Alice LOCAL AUTHORITY Role Users Alice LOCAL AUTHORITY Name Alice Alice LOCAL AUTHORITY NameIdentifier Alice’s user ID The table shows the most important aspect of claims, which is that I have already been using them when I implemented the traditional authentication and authorization features in Chapter 14. You can see that some of the claims relate to user identity (the Name claim is Alice, and the NameIdentifier claim is Alice’s unique user ID in my ASP.NET Identity database). 此表展示了声明(Claims)最重要的方面,这些是我在第14章中实现传统的认证和授权特性时,一直在使用的信息。可以看出,有些声明(Claims)与用户标识有关(Name声明是Alice,NameIdentifier声明是Alice在ASP.NET Identity数据库中的唯一用户ID号)。 Other claims show membership of roles—there are two Role claims in the table, reflecting the fact that Alice is assigned to both the Users and Employees roles. There is also a claim about how Alice has been authenticated: The IdentityProvider is set to ASP.NET Identity. 其他声明(Claims)显示了角色成员——表中有两个Role声明(Claim),体现出Alice被赋予了Users和Employees两个角色这一事实。还有一个是Alice已被认证的声明(Claim):IdentityProvider被设置到了ASP.NET Identity。 The difference when this information is expressed as a set of claims is that you can determine where the data came from. The Issuer property for all the claims shown in the table is set to LOCAL AUTHORITY, which indicates that the user’s identity has been established by the application. 当这种信息被表示成一组声明(Claims)时的差别是,你能够确定这些数据是从哪里来的。表中所显示的所有声明的Issuer属性(发布者)都被设置到了LOACL AUTHORITY(本地授权),这说明该用户的标识是由应用程序建立的。 So, now that you have seen some example claims, I can more easily describe what a claim is. A claim is any piece of information about a user that is available to the application, including the user’s identity and role memberships. And, as you have seen, the information I have been defining about my users in earlier chapters is automatically made available as claims by ASP.NET Identity. 因此,现在你已经看到了一些声明(Claims)示例,我可以更容易地描述声明(Claim)是什么了。一项声明(Claim)是可用于应用程序中的有关用户的一个信息片段,包括用户的标识以及角色成员等。而且,正如你所看到的,我在前几章定义的关于用户的信息,被ASP.NET Identity自动地作为声明(Claims)了。 15.3.2 Creating and Using Claims 15.3.2 创建和使用声明(Claims) Claims are interesting for two reasons. The first reason is that an application can obtain claims from multiple sources, rather than just relying on a local database for information about the user. You will see a real example of this when I show you how to authenticate users through a third-party system in the “Using Third-Party Authentication” section, but for the moment I am going to add a class to the example project that simulates a system that provides claims information. Listing 15-15 shows the contents of the LocationClaimsProvider.cs file that I added to the Infrastructure folder. 声明(Claims)比较有意思的原因有两个。第一个原因是应用程序可以从多个来源获取声明(Claims),而不是只能依靠本地数据库关于用户的信息。你将会看到一个实际的示例,在“使用第三方认证”小节中,将演示如何通过第三方系统来认证用户。不过,此刻我只打算在示例项目中添加一个类,用以模拟一个提供声明(Claims)信息的系统。清单15-15显示了我添加到Infrastructure文件夹中LocationClaimsProvider.cs文件的内容。 Listing 15-15. The Contents of the LocationClaimsProvider.cs File 清单15-15. LocationClaimsProvider.cs文件的内容 using System.Collections.Generic;using System.Security.Claims; namespace Users.Infrastructure {public static class LocationClaimsProvider {public static IEnumerable<Claim> GetClaims(ClaimsIdentity user) {List<Claim> claims = new List<Claim>();if (user.Name.ToLower() == "alice") {claims.Add(CreateClaim(ClaimTypes.PostalCode, "DC 20500"));claims.Add(CreateClaim(ClaimTypes.StateOrProvince, "DC"));} else {claims.Add(CreateClaim(ClaimTypes.PostalCode, "NY 10036"));claims.Add(CreateClaim(ClaimTypes.StateOrProvince, "NY"));}return claims;}private static Claim CreateClaim(string type, string value) {return new Claim(type, value, ClaimValueTypes.String, "RemoteClaims");} }} The GetClaims method takes a ClaimsIdentity argument and uses the Name property to create claims about the user’s ZIP code and state. This class allows me to simulate a system such as a central HR database, which would be the authoritative source of location information about staff, for example. GetClaims方法以ClaimsIdentity为参数,并使用Name属性创建了关于用户ZIP码(邮政编码)和州府的声明(Claims)。上述这个类使我能够模拟一个诸如中心化的HR数据库(人力资源数据库)之类的系统,它可能会成为全体职员的地点信息的权威数据源。 Claims are associated with the user’s identity during the authentication process, and Listing 15-16 shows the changes I made to the Login action method of the Account controller to call the LocationClaimsProvider class. 在认证过程期间,声明(Claims)是与用户标识关联在一起的,清单15-16显示了我对Account控制器中Login动作方法所做的修改,以便调用LocationClaimsProvider类。 Listing 15-16. Associating Claims with a User in the AccountController.cs File 清单15-16. AccountController.cs文件中用户用声明的关联 ...[HttpPost][AllowAnonymous][ValidateAntiForgeryToken]public async Task<ActionResult> Login(LoginModel details, string returnUrl) {if (ModelState.IsValid) {AppUser user = await UserManager.FindAsync(details.Name,details.Password);if (user == null) {ModelState.AddModelError("", "Invalid name or password.");} else {ClaimsIdentity ident = await UserManager.CreateIdentityAsync(user,DefaultAuthenticationTypes.ApplicationCookie); ident.AddClaims(LocationClaimsProvider.GetClaims(ident));AuthManager.SignOut();AuthManager.SignIn(new AuthenticationProperties {IsPersistent = false}, ident);return Redirect(returnUrl);} }ViewBag.returnUrl = returnUrl;return View(details);}... You can see the effect of the location claims by starting the application, authenticating as a user, and requesting the /Claim/Index URL. Figure 15-6 shows the claims for Alice. You may have to sign out and sign back in again to see the change. 为了看看这个地点声明(Claims)的效果,可以启动应用程序,以一个用户进行认证,并请求/Claim/Index URL。图15-6显示了Alice的声明(Claims)。你可能需要退出,然后再次登录才会看到发生的变化。 Figure 15-6. Defining additional claims for users 图15-6. 定义用户的附加声明 Obtaining claims from multiple locations means that the application doesn’t have to duplicate data that is held elsewhere and allows integration of data from external parties. The Claim.Issuer property tells you where a claim originated from, which helps you judge how accurate the data is likely to be and how much weight you should give the data in your application. Location data obtained from a central HR database is likely to be more accurate and trustworthy than data obtained from an external mailing list provider, for example. 从多个地点获取声明(Claims)意味着应用程序不必复制其他地方保持的数据,并且能够与外部的数据集成。Claim.Issuer属性(图15-6中的Issuer数据列——译者注)能够告诉你一个声明(Claim)的发源地,这有助于让你判断数据的精确程度,也有助于让你决定这类数据在应用程序中的权重。例如,从中心化的HR数据库获取的地点数据可能要比外部邮件列表提供器获取的数据更为精确和可信。 1. Applying Claims 1. 运用声明(Claims) The second reason that claims are interesting is that you can use them to manage user access to your application more flexibly than with standard roles. The problem with roles is that they are static, and once a user has been assigned to a role, the user remains a member until explicitly removed. This is, for example, how long-term employees of big corporations end up with incredible access to internal systems: They are assigned the roles they require for each new job they get, but the old roles are rarely removed. (The unexpectedly broad systems access sometimes becomes apparent during the investigation into how someone was able to ship the contents of the warehouse to their home address—true story.) 声明(Claims)有意思的第二个原因是,你可以用它们来管理用户对应用程序的访问,这要比标准的角色管理更为灵活。角色的问题在于它们是静态的,而且一旦用户已经被赋予了一个角色,该用户便是一个成员,直到明确地删除为止。例如,这意味着大公司的长期雇员,对内部系统的访问会十分惊人:他们每次在获得新工作时,都会赋予所需的角色,但旧角色很少被删除。(在调查某人为何能够将仓库里的东西发往他的家庭地址过程中发现,有时会出现异常宽泛的系统访问——真实的故事) Claims can be used to authorize users based directly on the information that is known about them, which ensures that the authorization changes when the data changes. The simplest way to do this is to generate Role claims based on user data that are then used by controllers to restrict access to action methods. Listing 15-17 shows the contents of the ClaimsRoles.cs file that I added to the Infrastructure. 声明(Claims)可以直接根据用户已知的信息对用户进行授权,这能够保证当数据发生变化时,授权也随之而变。此事最简单的做法是根据用户数据来生成Role声明(Claim),然后由控制器用来限制对动作方法的访问。清单15-17显示了我添加到Infrastructure中的ClaimsRoles.cs文件的内容。 Listing 15-17. The Contents of the ClaimsRoles.cs File 清单15-17. ClaimsRoles.cs文件的内容 using System.Collections.Generic;using System.Security.Claims; namespace Users.Infrastructure {public class ClaimsRoles {public static IEnumerable<Claim> CreateRolesFromClaims(ClaimsIdentity user) {List<Claim> claims = new List<Claim>();if (user.HasClaim(x => x.Type == ClaimTypes.StateOrProvince&& x.Issuer == "RemoteClaims" && x.Value == "DC")&& user.HasClaim(x => x.Type == ClaimTypes.Role&& x.Value == "Employees")) {claims.Add(new Claim(ClaimTypes.Role, "DCStaff"));}return claims;} }} The gnarly looking CreateRolesFromClaims method uses lambda expressions to determine whether the user has a StateOrProvince claim from the RemoteClaims issuer with a value of DC and a Role claim with a value of Employees. If the user has both claims, then a Role claim is returned for the DCStaff role. Listing 15-18 shows how I call the CreateRolesFromClaims method from the Login action in the Account controller. CreateRolesFromClaims是一个粗糙的考察方法,它使用了Lambda表达式,以检查用户是否具有StateOrProvince声明(Claim),该声明来自于RemoteClaims发行者(Issuer),值为DC。也检查用户是否具有Role声明(Claim),其值为Employees。如果用户这两个声明都有,那么便返回一个DCStaff角色的Role声明。清单15-18显示了如何在Account控制器中的Login动作中调用CreateRolesFromClaims方法。 Listing 15-18. Generating Roles Based on Claims in the AccountController.cs File 清单15-18. 在AccountController.cs中根据声明生成角色 ...[HttpPost][AllowAnonymous][ValidateAntiForgeryToken]public async Task<ActionResult> Login(LoginModel details, string returnUrl) {if (ModelState.IsValid) {AppUser user = await UserManager.FindAsync(details.Name,details.Password);if (user == null) {ModelState.AddModelError("", "Invalid name or password.");} else {ClaimsIdentity ident = await UserManager.CreateIdentityAsync(user,DefaultAuthenticationTypes.ApplicationCookie);ident.AddClaims(LocationClaimsProvider.GetClaims(ident)); ident.AddClaims(ClaimsRoles.CreateRolesFromClaims(ident));AuthManager.SignOut();AuthManager.SignIn(new AuthenticationProperties {IsPersistent = false}, ident);return Redirect(returnUrl);} }ViewBag.returnUrl = returnUrl;return View(details);}... I can then restrict access to an action method based on membership of the DCStaff role. Listing 15-19 shows a new action method I added to the Claims controller to which I have applied the Authorize attribute. 然后我可以根据DCStaff角色的成员,来限制对一个动作方法的访问。清单15-19显示了在Claims控制器中添加的一个新的动作方法,在该方法上已经运用了Authorize注解属性。 Listing 15-19. Adding a New Action Method to the ClaimsController.cs File 清单15-19. 在ClaimsController.cs文件中添加一个新的动作方法 using System.Security.Claims;using System.Web;using System.Web.Mvc;namespace Users.Controllers {public class ClaimsController : Controller {[Authorize]public ActionResult Index() {ClaimsIdentity ident = HttpContext.User.Identity as ClaimsIdentity;if (ident == null) {return View("Error", new string[] { "No claims available" });} else {return View(ident.Claims);} } [Authorize(Roles="DCStaff")]public string OtherAction() {return "This is the protected action";} }} Users will be able to access OtherAction only if their claims grant them membership to the DCStaff role. Membership of this role is generated dynamically, so a change to the user’s employment status or location information will change their authorization level. 只要用户的声明(Claims)承认他们是DCStaff角色的成员,那么他们便能访问OtherAction动作。该角色的成员是动态生成的,因此,若是用户的雇用状态或地点信息发生变化,也会改变他们的授权等级。 提示:请读者从这个例子中吸取其中的思想精髓。对于读物的理解程度,仁者见仁,智者见智,能领悟多少,全凭各人,译者感觉这里的思想有无数的可能。举例说明:(1)可以根据用户的身份进行授权,比如学生在校时是“学生”,毕业后便是“校友”;(2)可以根据用户所处的部门进行授权,人事部用户属于人事团队,销售部用户属于销售团队,各团队有其自己的应用;(3)下一小节的示例是根据用户的地点授权。简言之:一方面用户的各种声明(Claim)都可以用来进行授权;另一方面用户的声明(Claim)又是可以自定义的。于是可能的运用就无法估计了。总之一句话,这种基于声明的授权(Claims-Based Authorization)有无限可能!要是没有我这里的提示,是否所有读者在此处都会有所体会?——译者注 15.3.3 Authorizing Access Using Claims 15.3.3 使用声明(Claims)授权访问 The previous example is an effective demonstration of how claims can be used to keep authorizations fresh and accurate, but it is a little indirect because I generate roles based on claims data and then enforce my authorization policy based on the membership of that role. A more direct and flexible approach is to enforce authorization directly by creating a custom authorization filter attribute. Listing 15-20 shows the contents of the ClaimsAccessAttribute.cs file, which I added to the Infrastructure folder and used to create such a filter. 前面的示例有效地演示了如何用声明(Claims)来保持新鲜和准确的授权,但有点不太直接,因为我要根据声明(Claims)数据来生成了角色,然后强制我的授权策略基于角色成员。一个更直接且灵活的办法是直接强制授权,其做法是创建一个自定义的授权过滤器注解属性。清单15-20演示了ClaimsAccessAttribute.cs文件的内容,我将它添加在Infrastructure文件夹中,并用它创建了这种过滤器。 Listing 15-20. The Contents of the ClaimsAccessAttribute.cs File 清单15-20. ClaimsAccessAttribute.cs文件的内容 using System.Security.Claims;using System.Web;using System.Web.Mvc; namespace Users.Infrastructure {public class ClaimsAccessAttribute : AuthorizeAttribute {public string Issuer { get; set; }public string ClaimType { get; set; }public string Value { get; set; }protected override bool AuthorizeCore(HttpContextBase context) {return context.User.Identity.IsAuthenticated&& context.User.Identity is ClaimsIdentity&& ((ClaimsIdentity)context.User.Identity).HasClaim(x =>x.Issuer == Issuer && x.Type == ClaimType && x.Value == Value);} }} The attribute I have defined is derived from the AuthorizeAttribute class, which makes it easy to create custom authorization policies in MVC framework applications by overriding the AuthorizeCore method. My implementation grants access if the user is authenticated, the IIdentity implementation is an instance of ClaimsIdentity, and the user has a claim with the issuer, type, and value matching the class properties. Listing 15-21 shows how I applied the attribute to the Claims controller to authorize access to the OtherAction method based on one of the location claims created by the LocationClaimsProvider class. 我所定义的这个注解属性派生于AuthorizeAttribute类,通过重写AuthorizeCore方法,很容易在MVC框架应用程序中创建自定义的授权策略。在这个实现中,若用户是已认证的、其IIdentity实现是一个ClaimsIdentity实例,而且该用户有一个带有issuer、type以及value的声明(Claim),它们与这个类的属性是匹配的,则该用户便是允许访问的。清单15-21显示了如何将这个注解属性运用于Claims控制器,以便根据LocationClaimsProvider类创建的地点声明(Claim),对OtherAction方法进行授权访问。 Listing 15-21. Performing Authorization on Claims in the ClaimsController.cs File 清单15-21. 在ClaimsController.cs文件中执行基于声明的授权 using System.Security.Claims;using System.Web;using System.Web.Mvc;using Users.Infrastructure;namespace Users.Controllers {public class ClaimsController : Controller {[Authorize]public ActionResult Index() {ClaimsIdentity ident = HttpContext.User.Identity as ClaimsIdentity;if (ident == null) {return View("Error", new string[] { "No claims available" });} else {return View(ident.Claims);} } [ClaimsAccess(Issuer="RemoteClaims", ClaimType=ClaimTypes.PostalCode,Value="DC 20500")]public string OtherAction() {return "This is the protected action";} }} My authorization filter ensures that only users whose location claims specify a ZIP code of DC 20500 can invoke the OtherAction method. 这个授权过滤器能够确保只有地点声明(Claim)的邮编为DC 20500的用户才能请求OtherAction方法。 15.4 Using Third-Party Authentication 15.4 使用第三方认证 One of the benefits of a claims-based system such as ASP.NET Identity is that any of the claims can come from an external system, even those that identify the user to the application. This means that other systems can authenticate users on behalf of the application, and ASP.NET Identity builds on this idea to make it simple and easy to add support for authenticating users through third parties such as Microsoft, Google, Facebook, and Twitter. 基于声明的系统,如ASP.NET Identity,的好处之一是任何声明都可以来自于外部系统,即使是将用户标识到应用程序的那些声明。这意味着其他系统可以代表应用程序来认证用户,而ASP.NET Identity就建立在这样的思想之上,使之能够简单而方便地添加第三方认证用户的支持,如微软、Google、Facebook、Twitter等。 There are some substantial benefits of using third-party authentication: Many users will already have an account, users can elect to use two-factor authentication, and you don’t have to manage user credentials in the application. In the sections that follow, I’ll show you how to set up and use third-party authentication for Google users, which Table 15-8 puts into context. 使用第三方认证有一些实际的好处:许多用户已经有了账号、用户可以选择使用双因子认证、你不必在应用程序中管理用户凭据等等。在以下小节中,我将演示如何为Google用户建立并使用第三方认证,表15-8描述了事情的情形。 Table 15-8. Putting Third-Party Authentication in Context 表15-8. 第三方认证情形 Question 问题 Answer 回答 What is it? 什么是第三方认证? Authenticating with third parties lets you take advantage of the popularity of companies such as Google and Facebook. 第三方认证使你能够利用流行公司,如Google和Facebook,的优势。 Why should I care? 为何要关心它? Users don’t like having to remember passwords for many different sites. Using a provider with large-scale adoption can make your application more appealing to users of the provider’s services. 用户不喜欢记住许多不同网站的口令。使用大范围适应的提供器可使你的应用程序更吸引有提供器服务的用户。 How is it used by the MVC framework? 如何在MVC框架中使用它? This feature isn’t used directly by the MVC framework. 这不是一个直接由MVC框架使用的特性。 Note The reason I have chosen to demonstrate Google authentication is that it is the only option that doesn’t require me to register my application with the authentication service. You can get details of the registration processes required at http://bit.ly/1cqLTrE. 提示:我选择演示Google认证的原因是,它是唯一不需要在其认证服务中注册我应用程序的公司。有关认证服务注册过程的细节,请参阅http://bit.ly/1cqLTrE。 15.4.1 Enabling Google Authentication 15.4.1 启用Google认证 ASP.NET Identity comes with built-in support for authenticating users through their Microsoft, Google, Facebook, and Twitter accounts as well more general support for any authentication service that supports OAuth. The first step is to add the NuGet package that includes the Google-specific additions for ASP.NET Identity. Enter the following command into the Package Manager Console: ASP.NET Identity带有通过Microsoft、Google、Facebook以及Twitter账号认证用户的内建支持,并且对于支持OAuth的认证服务具有更普遍的支持。第一个步骤是添加NuGet包,包中含有用于ASP.NET Identity的Google专用附件。请在“Package Manager Console(包管理器控制台)”中输入以下命令: Install-Package Microsoft.Owin.Security.Google -version 2.0.2 There are NuGet packages for each of the services that ASP.NET Identity supports, as described in Table 15-9. 对于ASP.NET Identity支持的每一种服务都有相应的NuGet包,如表15-9所示。 Table 15-9. The NuGet Authenticaton Packages 表15-9. NuGet认证包 Name 名称 Description 描述 Microsoft.Owin.Security.Google Authenticates users with Google accounts 用Google账号认证用户 Microsoft.Owin.Security.Facebook Authenticates users with Facebook accounts 用Facebook账号认证用户 Microsoft.Owin.Security.Twitter Authenticates users with Twitter accounts 用Twitter账号认证用户 Microsoft.Owin.Security.MicrosoftAccount Authenticates users with Microsoft accounts 用Microsoft账号认证用户 Microsoft.Owin.Security.OAuth Authenticates users against any OAuth 2.0 service 根据任一OAuth 2.0服务认证用户 Once the package is installed, I enable support for the authentication service in the OWIN startup class, which is defined in the App_Start/IdentityConfig.cs file in the example project. Listing 15-22 shows the change that I have made. 一旦安装了这个包,便可以在OWIN启动类中启用此项认证服务的支持,启动类的定义在示例项目的App_Start/IdentityConfig.cs文件中。清单15-22显示了所做的修改。 Listing 15-22. Enabling Google Authentication in the IdentityConfig.cs File 清单15-22. 在IdentityConfig.cs文件中启用Google认证 using Microsoft.AspNet.Identity;using Microsoft.Owin;using Microsoft.Owin.Security.Cookies;using Owin;using Users.Infrastructure;using Microsoft.Owin.Security.Google;namespace Users {public class IdentityConfig {public void Configuration(IAppBuilder app) {app.CreatePerOwinContext<AppIdentityDbContext>(AppIdentityDbContext.Create);app.CreatePerOwinContext<AppUserManager>(AppUserManager.Create);app.CreatePerOwinContext<AppRoleManager>(AppRoleManager.Create); app.UseCookieAuthentication(new CookieAuthenticationOptions {AuthenticationType = DefaultAuthenticationTypes.ApplicationCookie,LoginPath = new PathString("/Account/Login"),}); app.UseExternalSignInCookie(DefaultAuthenticationTypes.ExternalCookie);app.UseGoogleAuthentication();} }} Each of the packages that I listed in Table 15-9 contains an extension method that enables the corresponding service. The extension method for the Google service is called UseGoogleAuthentication, and it is called on the IAppBuilder implementation that is passed to the Configuration method. 表15-9所列的每个包都含有启用相应服务的扩展方法。用于Google服务的扩展方法名称为UseGoogleAuthentication,它通过传递给Configuration方法的IAppBuilder实现进行调用。 Next I added a button to the Views/Account/Login.cshtml file, which allows users to log in via Google. You can see the change in Listing 15-23. 下一步骤是在Views/Account/Login.cshtml文件中添加一个按钮,让用户能够通过Google进行登录。所做的修改如清单15-23所示。 Listing 15-23. Adding a Google Login Button to the Login.cshtml File 清单15-23. 在Login.cshtml文件中添加Google登录按钮 @model Users.Models.LoginModel@{ ViewBag.Title = "Login";}<h2>Log In</h2> @Html.ValidationSummary()@using (Html.BeginForm()) {@Html.AntiForgeryToken();<input type="hidden" name="returnUrl" value="@ViewBag.returnUrl" /><div class="form-group"><label>Name</label>@Html.TextBoxFor(x => x.Name, new { @class = "form-control" })</div><div class="form-group"><label>Password</label>@Html.PasswordFor(x => x.Password, new { @class = "form-control" })</div><button class="btn btn-primary" type="submit">Log In</button>}@using (Html.BeginForm("GoogleLogin", "Account")) {<input type="hidden" name="returnUrl" value="@ViewBag.returnUrl" /><button class="btn btn-primary" type="submit">Log In via Google</button>} The new button submits a form that targets the GoogleLogin action on the Account controller. You can see this method—and the other changes I made the controller—in Listing 15-24. 新按钮递交一个表单,目标是Account控制器中的GoogleLogin动作。可从清单15-24中看到该方法,以及在控制器中所做的其他修改。 Listing 15-24. Adding Support for Google Authentication to the AccountController.cs File 清单15-24. 在AccountController.cs文件中添加Google认证支持 using System.Threading.Tasks;using System.Web.Mvc;using Users.Models;using Microsoft.Owin.Security;using System.Security.Claims;using Microsoft.AspNet.Identity;using Microsoft.AspNet.Identity.Owin;using Users.Infrastructure;using System.Web; namespace Users.Controllers {[Authorize]public class AccountController : Controller {[AllowAnonymous]public ActionResult Login(string returnUrl) {if (HttpContext.User.Identity.IsAuthenticated) {return View("Error", new string[] { "Access Denied" });}ViewBag.returnUrl = returnUrl;return View();}[HttpPost][AllowAnonymous][ValidateAntiForgeryToken]public async Task<ActionResult> Login(LoginModel details, string returnUrl) {if (ModelState.IsValid) {AppUser user = await UserManager.FindAsync(details.Name,details.Password);if (user == null) {ModelState.AddModelError("", "Invalid name or password.");} else {ClaimsIdentity ident = await UserManager.CreateIdentityAsync(user,DefaultAuthenticationTypes.ApplicationCookie); ident.AddClaims(LocationClaimsProvider.GetClaims(ident));ident.AddClaims(ClaimsRoles.CreateRolesFromClaims(ident)); AuthManager.SignOut();AuthManager.SignIn(new AuthenticationProperties {IsPersistent = false}, ident);return Redirect(returnUrl);} }ViewBag.returnUrl = returnUrl;return View(details);} [HttpPost][AllowAnonymous]public ActionResult GoogleLogin(string returnUrl) {var properties = new AuthenticationProperties {RedirectUri = Url.Action("GoogleLoginCallback",new { returnUrl = returnUrl})};HttpContext.GetOwinContext().Authentication.Challenge(properties, "Google");return new HttpUnauthorizedResult();}[AllowAnonymous]public async Task<ActionResult> GoogleLoginCallback(string returnUrl) {ExternalLoginInfo loginInfo = await AuthManager.GetExternalLoginInfoAsync();AppUser user = await UserManager.FindAsync(loginInfo.Login);if (user == null) {user = new AppUser {Email = loginInfo.Email,UserName = loginInfo.DefaultUserName,City = Cities.LONDON, Country = Countries.UK};IdentityResult result = await UserManager.CreateAsync(user);if (!result.Succeeded) {return View("Error", result.Errors);} else {result = await UserManager.AddLoginAsync(user.Id, loginInfo.Login);if (!result.Succeeded) {return View("Error", result.Errors);} }}ClaimsIdentity ident = await UserManager.CreateIdentityAsync(user,DefaultAuthenticationTypes.ApplicationCookie);ident.AddClaims(loginInfo.ExternalIdentity.Claims);AuthManager.SignIn(new AuthenticationProperties {IsPersistent = false }, ident);return Redirect(returnUrl ?? "/");}[Authorize]public ActionResult Logout() {AuthManager.SignOut();return RedirectToAction("Index", "Home");}private IAuthenticationManager AuthManager {get {return HttpContext.GetOwinContext().Authentication;} }private AppUserManager UserManager {get {return HttpContext.GetOwinContext().GetUserManager<AppUserManager>();} }} } The GoogleLogin method creates an instance of the AuthenticationProperties class and sets the RedirectUri property to a URL that targets the GoogleLoginCallback action in the same controller. The next part is a magic phrase that causes ASP.NET Identity to respond to an unauthorized error by redirecting the user to the Google authentication page, rather than the one defined by the application: GoogleLogin方法创建了AuthenticationProperties类的一个实例,并为RedirectUri属性设置了一个URL,其目标为同一控制器中的GoogleLoginCallback动作。下一个部分是一个神奇阶段,通过将用户重定向到Google认证页面,而不是应用程序所定义的认证页面,让ASP.NET Identity对未授权的错误进行响应: ...HttpContext.GetOwinContext().Authentication.Challenge(properties, "Google");return new HttpUnauthorizedResult();... This means that when the user clicks the Log In via Google button, their browser is redirected to the Google authentication service and then redirected back to the GoogleLoginCallback action method once they are authenticated. 这意味着,当用户通过点击Google按钮进行登录时,浏览器被重定向到Google的认证服务,一旦在那里认证之后,便被重定向回GoogleLoginCallback动作方法。 I get details of the external login by calling the GetExternalLoginInfoAsync of the IAuthenticationManager implementation, like this: 我通过调用IAuthenticationManager实现的GetExternalLoginInfoAsync方法,我获得了外部登录的细节,如下所示: ...ExternalLoginInfo loginInfo = await AuthManager.GetExternalLoginInfoAsync();... The ExternalLoginInfo class defines the properties shown in Table 15-10. ExternalLoginInfo类定义的属性如表15-10所示: Table 15-10. The Properties Defined by the ExternalLoginInfo Class 表15-10. ExternalLoginInfo类所定义的属性 Name 名称 Description 描述 DefaultUserName Returns the username 返回用户名 Email Returns the e-mail address 返回E-mail地址 ExternalIdentity Returns a ClaimsIdentity that identities the user 返回标识该用户的ClaimsIdentity Login Returns a UserLoginInfo that describes the external login 返回描述外部登录的UserLoginInfo I use the FindAsync method defined by the user manager class to locate the user based on the value of the ExternalLoginInfo.Login property, which returns an AppUser object if the user has been authenticated with the application before: 我使用了由用户管理器类所定义的FindAsync方法,以便根据ExternalLoginInfo.Login属性的值对用户进行定位,如果用户之前在应用程序中已经认证,该属性会返回一个AppUser对象: ...AppUser user = await UserManager.FindAsync(loginInfo.Login);... If the FindAsync method doesn’t return an AppUser object, then I know that this is the first time that this user has logged into the application, so I create a new AppUser object, populate it with values, and save it to the database. I also save details of how the user logged in so that I can find them next time: 如果FindAsync方法返回的不是AppUser对象,那么我便知道这是用户首次登录应用程序,于是便创建了一个新的AppUser对象,填充该对象的值,并将其保存到数据库。我还保存了用户如何登录的细节,以便下次能够找到他们: ...result = await UserManager.AddLoginAsync(user.Id, loginInfo.Login);... All that remains is to generate an identity the user, copy the claims provided by Google, and create an authentication cookie so that the application knows the user has been authenticated: 剩下的事情只是生成该用户的标识了,拷贝Google提供的声明(Claims),并创建一个认证Cookie,以使应用程序知道此用户已认证: ...ClaimsIdentity ident = await UserManager.CreateIdentityAsync(user,DefaultAuthenticationTypes.ApplicationCookie);ident.AddClaims(loginInfo.ExternalIdentity.Claims);AuthManager.SignIn(new AuthenticationProperties { IsPersistent = false }, ident);... 15.4.2 Testing Google Authentication 15.4.2 测试Google认证 There is one further change that I need to make before I can test Google authentication: I need to change the account verification I set up in Chapter 13 because it prevents accounts from being created with e-mail addresses that are not within the example.com domain. Listing 15-25 shows how I removed the verification from the AppUserManager class. 在测试Google认证之前还需要一处修改:需要修改第13章所建立的账号验证,因为它不允许example.com域之外的E-mail地址创建账号。清单15-25显示了如何在AppUserManager类中删除这种验证。 Listing 15-25. Disabling Account Validation in the AppUserManager.cs File 清单15-25. 在AppUserManager.cs文件中取消账号验证 using Microsoft.AspNet.Identity;using Microsoft.AspNet.Identity.EntityFramework;using Microsoft.AspNet.Identity.Owin;using Microsoft.Owin;using Users.Models; namespace Users.Infrastructure {public class AppUserManager : UserManager<AppUser> {public AppUserManager(IUserStore<AppUser> store): base(store) {}public static AppUserManager Create(IdentityFactoryOptions<AppUserManager> options,IOwinContext context) {AppIdentityDbContext db = context.Get<AppIdentityDbContext>();AppUserManager manager = new AppUserManager(new UserStore<AppUser>(db)); manager.PasswordValidator = new CustomPasswordValidator {RequiredLength = 6,RequireNonLetterOrDigit = false,RequireDigit = false,RequireLowercase = true,RequireUppercase = true}; //manager.UserValidator = new CustomUserValidator(manager) {// AllowOnlyAlphanumericUserNames = true,// RequireUniqueEmail = true//};return manager;} }} Tip you can use validation for externally authenticated accounts, but I am just going to disable the feature for simplicity. 提示:也可以使用外部已认证账号的验证,但这里出于简化,取消了这一特性。 To test authentication, start the application, click the Log In via Google button, and provide the credentials for a valid Google account. When you have completed the authentication process, your browser will be redirected back to the application. If you navigate to the /Claims/Index URL, you will be able to see how claims from the Google system have been added to the user’s identity, as shown in Figure 15-7. 为了测试认证,启动应用程序,通过点击“Log In via Google(通过Google登录)”按钮,并提供有效的Google账号凭据。当你完成了认证过程时,浏览器将被重定向回应用程序。如果导航到/Claims/Index URL,便能够看到来自Google系统的声明(Claims),已被添加到用户的标识中了,如图15-7所示。 Figure 15-7. Claims from Google 图15-7. 来自Google的声明(Claims) 15.5 Summary 15.5 小结 In this chapter, I showed you some of the advanced features that ASP.NET Identity supports. I demonstrated the use of custom user properties and how to use database migrations to preserve data when you upgrade the schema to support them. I explained how claims work and how they can be used to create more flexible ways of authorizing users. I finished the chapter by showing you how to authenticate users via Google, which builds on the ideas behind the use of claims. 本章向你演示了ASP.NET Identity所支持的一些高级特性。演示了自定义用户属性的使用,还演示了在升级数据架构时,如何使用数据库迁移保护数据。我解释了声明(Claims)的工作机制,以及如何将它们用于创建更灵活的用户授权方式。最后演示了如何通过Google进行认证结束了本章,这是建立在使用声明(Claims)的思想基础之上的。 本篇文章为转载内容。原文链接:https://blog.csdn.net/gz19871113/article/details/108591802。 该文由互联网用户投稿提供,文中观点代表作者本人意见,并不代表本站的立场。 作为信息平台,本站仅提供文章转载服务,并不拥有其所有权,也不对文章内容的真实性、准确性和合法性承担责任。 如发现本文存在侵权、违法、违规或事实不符的情况,请及时联系我们,我们将第一时间进行核实并删除相应内容。
2023-10-28 08:49:21
283
转载
SpringCloud
随着微服务架构的广泛应用,用户认证和鉴权机制的重要性日益凸显。近期,业界对此问题的研究与实践也在不断深化。例如,在2021年云栖大会上,阿里云就提出了“零信任安全”体系下的统一身份认证与授权解决方案,强调在服务间通信时需依托于可信的身份识别和动态访问控制策略,通过在API网关等入口环节实施集中式的强认证,并结合服务端能力进行细粒度的权限校验。 另一方面,Netflix开源的OSS项目如OAuth2、Spring Cloud Security等为微服务环境下的认证鉴权提供了强有力的支持。其中,Spring Cloud Gateway作为微服务架构中的核心组件,其自带的全局过滤器功能可以方便地实现统一的认证鉴权逻辑,不仅简化了开发流程,还增强了系统的安全性。 同时,随着Service Mesh技术的发展,Istio等服务网格解决方案也在用户认证与鉴权方面展现出强大的潜力。它们可以通过Sidecar代理对进出服务网格的所有请求进行拦截和身份验证,进一步加强了跨服务通信的安全性。 综上所述,无论是采取服务内部独立处理,还是选择在网关层集中管控,抑或是借助新兴的Service Mesh架构,都需要根据实际业务场景和安全需求灵活设计和实施认证鉴权策略,以适应现代分布式系统安全防护的新挑战。
2023-04-09 17:26:14
98
幽谷听泉_t
SpringBoot
...期,在软件开发领域,微服务架构因其能够提升系统的可扩展性和灵活性而备受关注。微服务架构将应用程序拆分为一组小型的服务,每个服务都在自己的进程中运行,并通过轻量级通信机制进行交互。这种架构模式非常适合于大规模的应用部署,特别是在云环境中。 例如,Netflix公司就是一个很好的例子。Netflix通过采用微服务架构,成功地将其庞大的视频流媒体服务分解为众多小服务,每个服务负责系统的一个特定功能,如用户认证、视频编码、内容推荐等。这种设计使得Netflix能够快速迭代和部署新功能,同时保持系统的稳定性和可靠性。 然而,微服务架构并非没有挑战。其中一个主要问题是服务间的通信复杂度增加,以及服务治理变得更为困难。为了解决这些问题,开发者和企业正在探索各种解决方案,如API网关、服务网格技术等。这些技术有助于简化服务间通信,提供服务发现、负载均衡等功能,从而提高系统的整体性能和稳定性。 此外,随着Kubernetes等容器编排平台的发展,微服务架构的部署和管理变得更加高效。Kubernetes提供了一种标准化的方式来管理和扩展容器化应用,使得微服务架构的部署更加灵活和可靠。 总之,微服务架构作为一种现代软件开发趋势,正推动着软件工程领域的创新。通过借鉴Netflix等公司的实践经验,开发者和企业可以更好地应对微服务架构所带来的挑战,构建出更加健壮和高效的系统。未来,随着技术的进步,我们可以期待看到更多创新的解决方案,使微服务架构成为软件开发的标准范式。
2025-02-24 16:06:23
73
雪落无痕_
转载文章
微服务框架 , 微服务框架是一种软件架构模式,它将大型复杂应用程序分解为一组小型、独立的服务。在JeeWx捷微V3.3版本中,该平台采用微服务框架构建,意味着各个功能模块如微信公众号管理、素材管理、用户消息处理等被设计为可独立部署和运行的服务单元,每个服务都拥有自己的业务逻辑并可通过API接口进行通信协作,从而实现系统的高可用性、可扩展性和易于维护性。 小程序接口 , 小程序接口是微信或支付宝等平台为开发者提供的编程接口,允许开发者通过调用这些接口来实现与小程序的交互和数据交换。在JeeWx捷微V3.3版本中,升级了小程序接口意味着增强了对小程序开发的支持,例如可以更方便地对接小程序进行用户身份验证、获取用户信息、发送模板消息以及进行支付等相关操作,以满足不同场景下的业务需求。 微信第三方平台(全网发布) , 微信第三方平台是指经微信官方授权认证,能够提供微信公众号、小程序等微信生态下各类产品技术开发与运营服务的平台。在JeeWx捷微V3.3版本中提到的“全网发布”功能,表明该平台具备支持跨多个公众号或小程序的统一管理和运维能力,企业或开发者可以在该平台上实现多账号资源的一体化管理和配置,如菜单设置、素材管理、消息回复等功能,并且能够一键同步到所有关联的公众号或小程序上,大大提高了工作效率和运维便利性。
2023-08-22 14:35:00
296
转载
Nacos
...Nacos修改密码后服务无法启动的问题及其解决方案后,我们发现此类问题其实反映出了微服务架构中配置管理和安全性维护的重要性。近期,随着云原生和DevOps理念的普及,如何确保服务配置的安全与一致性成为了业界关注的重点。 2021年,阿里巴巴集团在《阿里云Nacos最佳实践白皮书》中特别强调了对配置中心安全性的强化,提倡使用统一的身份认证和授权机制,如OAuth2、JWT等,并提醒用户及时更新和同步密码等敏感信息以避免服务中断。 此外,对于微服务架构中的配置管理,CNCF(Cloud Native Computing Foundation)社区也推出了Config Connector等工具,旨在提供一种集中式、安全可靠的方式来管理Kubernetes集群中的资源配置和服务账户权限,从而有效防止因配置变更带来的服务异常情况。 总的来说,在现代分布式系统中,正确处理配置服务的访问控制与密码策略是保证系统稳定运行的关键一环。通过持续关注行业动态和最佳实践,结合文中所述的具体解决办法,我们可以更好地应对类似Nacos密码修改后服务启动失败这类问题,实现更加稳健的微服务运维管理。
2024-01-03 10:37:31
117
月影清风_t
Java
...支持为我们提供了有效方案,但随着Web应用的发展和安全要求的提升,跨域策略的制定与实施变得更为复杂且重要。近期,一些浏览器厂商为了进一步增强安全性,已经开始逐步收紧对跨域请求的控制政策。 例如,Chrome浏览器自2021年起开始实施更严格的同源策略更新,对于部分不安全的CORS配置(如设置Access-Control-Allow-Origin为''通配符),将逐渐拒绝执行。因此,在实际项目中,开发者需要更加精细地管理允许的源列表,确保只有经过验证的安全来源才能进行跨域访问。 同时,随着API经济的崛起,微服务架构的普及,服务间跨域调用的需求愈发频繁。为此,企业级解决方案如Kubernetes Ingress、API Gateway等在处理跨域问题上也提供了丰富且强大的功能支持,如动态配置CORS规则、基于身份认证或授权策略来灵活控制跨域访问权限等。 此外,对于深入理解和实践跨域策略,W3C关于CORS的标准文档始终是最权威的参考资料。通过研读规范,不仅可以了解CORS机制的全貌,还能掌握如何针对不同场景设计并实施恰当的跨域策略,从而在保障系统安全的同时,优化用户体验,提升系统的整体性能表现。
2023-08-14 17:20:09
268
幽谷听泉_t
Tomcat
...t远程管理的新趋势:微服务架构与云原生集成》 随着微服务架构的兴起和云计算的普及,Tomcat的远程管理正在经历一场革命。如今,许多开发者不再局限于单一的Tomcat实例,而是将其融入到云原生环境中,如Kubernetes和Docker。这促使了对Tomcat的API Gateway和服务发现机制的重新思考。 首先,微服务架构下的Tomcat管理强调的是服务化和API化,如使用Spring Cloud Gateway提供统一的API入口,使得远程管理更加模块化和灵活。同时,容器化技术如Docker的使用,使得Tomcat可以在多个环境中无缝部署,简化了版本管理和部署流程。 其次,云原生集成带来了新的安全挑战和解决方案。比如,Kubernetes的Service Account和Role-Based Access Control(RBAC)可以帮助管理远程对Tomcat的访问权限,同时,云平台的自动扩缩容功能也减轻了运维压力。 此外,Kubernetes的Ingress Controller和TLS Termination在HTTPS流量管理上提供了新的可能性,使得Tomcat在云端的性能和安全性得到提升。 总的来说,现代Tomcat的远程管理已经从单一服务器扩展到整个微服务生态,这不仅需要开发者掌握新的工具和技术,也需要理解和适应云原生的思维模式。持续关注云原生技术的发展和最佳实践,对于提升Tomcat管理的效率和安全性至关重要。
2024-06-17 11:00:56
264
翡翠梦境
SpringCloud
...可以帮助我们快速构建微服务架构。然而,随着微服务一个接一个冒出来,数量蹭蹭上涨,如何把这些小家伙们妥善地管起来,确保它们的安全,已然变成一个亟待解决的大问题了。在这个问题上,SpringCloud提供了两种解决方案:网关和访问权限管理。本文将重点讨论这两种解决方案,并通过代码示例进行详细讲解。 二、SpringCloud网关 SpringCloud网关是SpringCloud提供的一个用于统一管理和控制微服务访问的工具。它可以提供一些高级功能,如路由、过滤器、安全策略等。下面我们来看一个简单的例子: typescript @Configuration @EnableWebFluxSecurity public class SecurityConfig extends WebFluxConfigurerAdapter { @Override public void addCorsMappings(CorsRegistry registry) { registry.addMapping("/api/") .allowedOrigins("http://localhost:8080"); } } 上述代码定义了一个名为SecurityConfig的配置类,并继承自WebFluxConfigurerAdapter。在addCorsMappings这个小功能里,我们捣鼓出了一条全新的CORS规则。这条规则的意思是,所有从http://localhost:8080这个地址发起的请求,都能无障碍地访问到/api/路径下的全部资源,一个都不能少! 三、SpringCloud访问权限管理 除了提供网关外,SpringCloud还提供了一种名为OAuth2的身份验证协议,用于管理用户的访问权限。OAuth2允许用户授权给第三方应用程序,而无需直接共享他们的登录凭据。这下子,我们就能更灵活地掌控用户访问权限了,同时也能贴心地守护每位用户的隐私安全。下面我们来看一个简单的例子: java @RestController @RequestMapping("/api") public class UserController { @Autowired private UserRepository userRepository; @GetMapping("/{id}") @PreAuthorize("@permissionEvaluator.hasPermission(principal, 'READ', 'USER')") public User getUser(@PathVariable long id) { return userRepository.findById(id).orElseThrow(() -> new UserNotFoundException()); } } 上述代码定义了一个名为UserController的控制器,其中包含一个获取特定用户的方法。这个方法第一步会用到一个叫@PreAuthorize的注解,这个小家伙的作用呢,就好比一道安全门禁,只有那些手握“读取用户权限”钥匙的用户,才能顺利地执行接下来的操作。然后,它查询数据库并返回用户信息。 四、结论 总的来说,SpringCloud的网关和访问权限管理都是非常强大的工具,它们可以帮助我们更有效地管理和保护我们的微服务。不过呢,咱们得留个心眼儿,这些工具可不是拿起来就能随便使的,得好好地调校和操作,否则一不留神,可能会闹出些意料之外的幺蛾子来。所以,我们在动手用这些工具的时候,最好先摸清楚它们是怎么运转的,同时也要保证咱们编写的代码没有bug,是完全正确的。只有这样子,我们才能够实实在在地把这些工具的威力给发挥出来,打造出一个既稳如磐石、又靠得住、还安全无忧的微服务系统。
2023-07-15 18:06:53
434
山涧溪流_t
HessianRPC
...展表明,随着云计算和微服务架构的普及,新的挑战和最佳实践正在不断涌现。例如,AWS推出了一项名为Amazon API Gateway的托管服务,内置了智能连接池管理,可根据实时流量自动调整连接数量,这对于大规模HessianRPC部署具有重要意义。 Google Cloud也发布了新的优化策略,他们提倡使用gRPC作为替代方案,其内置的高性能HTTP/2和流处理能力,使得连接池管理更加高效。同时,Google强调了服务网格(Service Mesh)在连接池管理中的角色,通过统一的控制平面,实现全局的连接池优化和流量治理。 另外,Apache Netty等开源框架也在不断更新,引入了更多的高级功能,如异步I/O和多路复用,这进一步提升了连接池的性能。同时,对连接池优化的实时监控和自动调整算法的研究也在机器学习和数据科学的驱动下取得突破,比如使用AI预测模型来动态调整连接池大小。 总的来说,HessianRPC的连接池优化不再是孤立的技术问题,而是与整个系统架构、云服务和新兴技术紧密结合。开发者和架构师需要密切关注这些最新动态,以便在实际项目中做出最佳决策,实现更高效的分布式系统。
2024-03-31 10:36:28
503
寂静森林
Consul
微服务架构 , 微服务架构是一种软件开发技术,它将大型的单一应用程序分解为一组小型、独立的服务。每个服务运行在其自己的进程中,服务之间通过API进行通信。这种架构模式允许每个服务独立部署、扩展和维护,并且可以使用不同的编程语言和技术栈实现,从而提高了系统的灵活性、可伸缩性和容错性。 服务发现 , 在分布式系统尤其是微服务架构中,服务发现是指一种机制,使得服务提供者能够自动地将自己的位置(如IP地址和端口号)注册到服务注册中心,而服务消费者则可以通过查询这个中心来找到并连接对应的服务实例。Consul作为服务发现工具,提供了这一功能,确保了服务之间的动态寻址和通信。 配置管理 , 配置管理是软件开发与运维过程中的关键环节,涉及对软件系统及组件的配置信息进行统一管理和分发。在Consul中,配置管理功能允许开发者集中存储和管理所有服务的配置信息,当配置发生变化时,Consul能实时将更新推送到各个服务实例,实现了配置的版本控制和动态更新,有助于提升系统稳定性和运维效率。 Consul Connect , Consul Connect是Consul提供的服务网格解决方案的一部分,它通过在服务间通信中引入身份认证、授权和加密等安全措施,强化了服务间的信任和安全性。Connect允许用户定义服务间通信的策略,并通过Sidecar代理自动实施这些策略,从而简化了构建和运维安全微服务环境的过程。
2023-08-15 16:36:21
442
月影清风-t
转载文章
...协议相结合搭建Web服务器后,您可能会对以下内容感兴趣: 随着云原生和微服务架构的普及,基于RESTful API设计原则的WebService已成为现代应用开发的标准实践。最新的API网关技术如Kong、Envoy等,不仅提供了统一的安全认证、限流熔断等治理能力,还能简化WebService接口的管理和部署。例如,一篇近期的技术文章《使用Kong构建可扩展的微服务API网关》深入探讨了如何利用此类工具优化WebService性能,并确保其在大规模分布式环境中的高可用性。 另外,HTTP/3作为HTTP协议的最新版本,正在逐步被各大主流浏览器及服务器支持。相较于HTTP/1.1和HTTP/2,HTTP/3引入了QUIC协议,提供更快的连接建立速度、多路复用无阻塞传输,有效解决了延迟和丢包问题。阅读关于HTTP/3的最新研究与实践案例,比如《HTTP/3:下一代互联网传输协议的变革与应用》,将有助于我们掌握未来WebService通信的新趋势和技术细节。 此外,对于安全防护方面,随着网络攻击手段的日益复杂化,保障WebService的安全性至关重要。一篇题为《深度解析:如何强化你的WebService安全防护体系》的文章详述了多种常见的安全威胁及应对策略,包括但不限于DDoS防御、SQL注入防范、OAuth2.0授权机制的应用等,这对于提升自建WebService的安全等级具有极高的参考价值。 综上所述,在实际开发和运维过程中,结合最新的技术和最佳实践,不断优化和完善WebService的实现方案,既能提高系统的稳定性和效率,也能确保其在面对各种挑战时具备足够的安全性和适应性。
2023-05-30 18:31:58
90
转载
Docker
...er官方宣布对x86架构的全面支持,容器化技术在主流硬件平台上的应用得到了进一步拓宽。这一举措不仅简化了开发人员在不同架构间迁移应用程序的过程,也为大量使用x86服务器的企业带来了显著的灵活性和成本效益。 实际上,在当前云计算和微服务架构盛行的时代背景下,跨平台能力对于任何一款容器化工具而言都至关重要。近日,有业内专家指出,Docker对x86的支持优化将进一步巩固其在企业级IT基础设施中的地位,尤其在混合云部署、持续集成/持续部署(CI/CD)流程以及边缘计算等场景下将发挥更大作用。 此外,值得注意的是,尽管Docker为x86架构提供了原生级别的支持,但在ARM等其他架构上,Docker也同样展现出强大的适应性和性能表现。这与Docker倡导的“一次构建,到处运行”理念相得益彰,意味着用户可以期待在未来享受到更加无缝且统一的应用程序部署体验。 同时,随着Kubernetes等容器编排系统的广泛应用,Docker作为核心组件,其对x86架构的支持亦有望提升整体集群的稳定性和资源利用率。未来,我们期待看到更多的开发者和企业能够充分利用这一特性,推动软件交付方式的创新和升级。 总之,Docker对x86架构的支持是容器技术生态发展的重要里程碑,它将在持续推动云计算和DevOps领域进步的同时,为全球范围内的企业和开发者带来更高的效率和更佳的实践体验。
2023-08-31 13:21:01
540
代码侠
Docker
...力,并能与各类云存储服务无缝对接,实现日志数据长期保存和合规性要求。 与此同时,容器可观测性领域也有了新的突破。OpenTelemetry项目提供了一套跨平台的标准和工具集,可统一收集包括容器日志在内的各项指标、跟踪和日志信息,大大提升了分布式系统中问题定位的效率和准确性。 在实际应用中,为了更好地满足微服务架构下容器日志的安全性和一致性需求,越来越多的企业开始采用服务网格技术如Istio来增强日志治理能力,通过统一的日志策略管理和审计,确保了容器环境下的日志安全性与合规性。 因此,在掌握Docker日志基本操作的基础上,关注日志领域的最新技术和解决方案,对于提升云原生环境下的运维效率与保障系统稳定性具有重要意义。不断学习和了解这些先进的日志处理手段,将有助于我们在日常工作中应对复杂场景,有效利用日志信息驱动系统的持续优化和改进。
2023-09-05 21:33:01
333
代码侠
.net
...事实上,近年来,随着微服务架构的广泛应用以及对代码质量和可维护性要求的不断提高,像Fody这类能够提升开发效率、优化代码结构的工具愈发受到开发者们的青睐。 近期,.NET社区中对于自动化编程实践的关注度持续升温,其中一项重要议题便是如何更好地运用AOP(面向切面编程)技术来减少冗余代码和增强系统可扩展性。Fody作为一款优秀的AOP实现工具,提供了诸如AutoDI(自动依赖注入)、NullGuard(空值保护)和PropertyChanged(属性变更通知)等一系列插件,进一步丰富和完善了.NET生态下的AOP解决方案。 同时,微软在.NET 5及后续版本中不断加强对IL级别编程的支持,这也为Fody等基于Mono.Cecil的库提供了更广阔的发展空间。在未来,我们有望看到更多利用此类工具解决实际开发问题的成功案例和最佳实践,帮助开发者们构建更为简洁、高效且易于维护的应用程序。 此外,尽管Fody功能强大,但同时也需注意其在生产环境中的应用可能带来的性能影响和调试复杂性。因此,在使用过程中建议结合具体的项目需求和团队规范,合理评估和选择适用的Fody插件,并确保对编译后生成的代码有充分的理解与控制,以实现真正的代码优化与工程化升级。
2023-09-26 08:21:49
470
诗和远方-t
Go Gin
...如如何利用Gin构建微服务架构、实现认证授权机制等深度内容。 另外,值得关注的是,随着云原生和无服务器架构的普及,Gin框架在Kubernetes和Serverless环境下的部署与应用也成为热门话题。许多开发者正在探讨如何借助Gin构建轻量级、高性能的云函数,或是在Service Mesh架构下优化API网关的设计。 因此,推荐读者关注Gin官方文档及GitHub项目更新,及时了解最新功能和优化方案;同时,参与相关的技术论坛和博客,以便掌握更多实战技巧和行业趋势,助力您的Web开发之旅更加得心应手。
2023-01-16 08:55:08
433
月影清风-t
.net
...要功能就是提供了一种统一、便捷的方式来执行SQL命令。不过呢,在实际动手用SqlHelper类封装数据插入功能的时候,咱们偶尔会碰到一些看着不起眼儿,但实际上却至关重要的小问题。本文将带大家一起探讨这些问题,并通过实例代码来揭示解决之道。 2. SqlHelper类简介 SqlHelper是.NET框架下一种常用的数据库操作工具类,它封装了ADO.NET中的SqlConnection、SqlCommand等对象,简化了数据库的操作过程。下面是一个基础的SqlHelper类的插入数据方法示例: csharp public static int ExecuteNonQuery(string connectionString, string commandText, params SqlParameter[] commandParameters) { using (SqlConnection connection = new SqlConnection(connectionString)) { SqlCommand cmd = new SqlCommand(commandText, connection); cmd.CommandType = CommandType.Text; if (commandParameters != null) cmd.Parameters.AddRange(commandParameters); connection.Open(); int result = cmd.ExecuteNonQuery(); return result; } } 3. 插入数据时可能遇到的问题及其解决方案 (1)问题一:参数化SQL语句异常 有时候,我们在调用SqlHelper类执行插入数据操作时,可能会遇到因参数化SQL语句设置不当导致的异常。例如,参数数量与SQL语句中的问号不匹配: csharp string sql = "INSERT INTO Users (Name, Email) VALUES (?, ?)"; SqlParameter[] parameters = { new SqlParameter("@Name", "John Doe"), new SqlParameter("@Email", "john.doe@example.com"), new SqlParameter("@Age", 30) }; int rowsAffected = SqlHelper.ExecuteNonQuery(connectionString, sql, parameters); 这里,SQL语句只有两个问号占位符,但提供了三个参数,运行时会引发错误。为了解决这个问题,我们需要确保参数数量和SQL语句中的占位符数量一致: csharp string sql = "INSERT INTO Users (Name, Email, Age) VALUES (?, ?, ?)"; (2)问题二:空值处理 在插入数据时,如果字段允许为空,但在实际插入时未给该字段赋值,也可能导致异常。比如: csharp string sql = "INSERT INTO Users (Name, Email, PasswordHash) VALUES (?, ?, ?)"; SqlParameter[] parameters = { new SqlParameter("@Name", "John Doe"), new SqlParameter("@Email", "john.doe@example.com") }; 在上述代码中,PasswordHash字段没有赋予任何值。为了正确处理这种情况,我们可以设定DBNull.Value或者根据数据库表结构调整SQL语句: csharp parameters = { new SqlParameter("@Name", "John Doe"), new SqlParameter("@Email", "john.doe@example.com"), new SqlParameter("@PasswordHash", DBNull.Value) }; 或者修改SQL语句为: csharp string sql = "INSERT INTO Users (Name, Email) VALUES (?, ?)"; 4. 总结与思考 封装SqlHelper类进行数据插入时,虽然能极大提高开发效率,但也要注意细节处理。这包括但不限于参数化SQL语句的准确构建以及对空值的合理处理。在实际操作中,咱们得化身成侦探,用鹰眼般的敏锐洞察力揪出问题所在。同时,咱还要巧妙借助.net这个强大工具箱,灵活采取各种招数去摆平这些问题,这样一来,就能确保数据操作既稳如磐石又安全无虞啦!这就是编程让人着迷的地方,每遇到一个挑战,就像是给你塞了个成长的礼包,每一个解决的问题,都是你在技术道路上留下的扎实脚印,步步向前。
2023-09-22 13:14:39
507
繁华落尽_
转载文章
...化、标准化的配置管理方案,能够实现配置的统一管理和推送,支持多环境、多数据中心部署,适用于微服务架构中众多服务和应用的配置管理。 分布式部署 , 在计算机网络和系统架构领域,分布式部署是指将一个系统或应用的不同组件部署在多个独立的物理或虚拟服务器上,各组件之间通过网络进行通信和协作。在本文语境下,Apollo的分布式部署指按照特定指南将其三个核心服务(configservice、adminservice、portal)分别部署在不同的服务器或容器中,以达到高可用、可扩展的目标。 Apollo-ConfigService , Apollo项目中的一个关键服务模块,负责配置数据的存储、读取以及变更推送等功能。ConfigService与数据库交互,存储和管理所有应用和服务的配置信息,并通过服务发现机制与其它服务组件协同工作,确保配置数据的实时性和一致性。 Eureka , Eureka是一个由Netflix开发的服务注册与发现工具,用于实现微服务架构中的服务治理。在Apollo的上下文中,Eureka.service.url字段被用作Apollo-ConfigService服务的注册地址,在数据库中配置此地址是为了让其他服务能准确找到并连接到ConfigService,从而获取或更新配置信息。
2023-04-16 10:44:16
329
转载
Struts2
...据格式。 同时,随着微服务架构的流行,Reactive编程模型逐渐崭露头角,Spring WebFlux作为Spring Framework 5引入的非阻塞式、反应式编程模型,以其异步、非阻塞特性显著提升了系统性能和可伸缩性,其结果处理方式也具有鲜明的时代特色。 因此,在应对Action方法返回值映射问题时,除了掌握传统的Struts2解决方案,了解并适时运用Spring MVC等现代Java Web框架的新特性和最佳实践,无疑将助力开发者在瞬息万变的技术浪潮中游刃有余,持续提升项目的稳定性和开发效率。
2023-07-16 19:18:49
80
星河万里
Docker
...一个可移植的镜像中,用户可以使用该镜像创建并运行一个隔离且独立于宿主机系统的容器实例,确保应用程序在不同环境中的一致性和高效性。 容器化 , 容器化是一种操作系统级别的虚拟化技术,通过将应用程序及其依赖库、配置文件等封装在一个称为“容器”(如Docker容器)的隔离环境中运行,实现了资源的高效利用与管理。每个容器共享主机操作系统的内核,但拥有自己的文件系统、进程空间、网络接口等资源,从而实现应用的快速部署、版本控制以及跨平台运行能力。 Docker Hub , Docker Hub是Docker官方提供的在线镜像仓库,允许用户上传、存储和分享自己构建的Docker镜像,同时也提供了大量由社区和官方维护的标准软件镜像供用户直接下载和使用。通过Docker Hub,开发人员能够方便地获取所需的运行环境和依赖组件,极大地简化了软件开发、测试及部署流程。 Docker Swarm , Docker Swarm是Docker生态系统中的集群管理工具,它将一组物理或虚拟主机作为一个单一的虚拟Docker引擎来管理和调度容器。Swarm模式下,用户可以通过统一的API或命令行界面,在整个集群范围内进行容器服务的部署、扩展和故障转移,以实现高可用性和水平扩展能力。 Docker Compose , Docker Compose是一种用于定义和运行多容器Docker应用程序的工具,通过编写一个YAML格式的Compose文件,用户可以简洁明了地定义多个容器之间的关系和服务依赖,并一键启动所有相关容器。这使得开发者能够轻松地搭建和管理复杂的应用程序堆栈,包括数据库、Web服务器、缓存服务等多种微服务架构场景。
2023-01-02 19:11:15
391
电脑达人
Maven
...赖管理提供了新的解决方案。 此外,随着云原生和微服务架构的发展,容器化和标准化交付的需求日益增强,像Jenkins X、Tekton等CI/CD工具集成了更为强大的依赖管理能力,通过与Kubernetes的集成,确保了应用从构建到部署过程中依赖版本的一致性。 综上所述,在不断演进的技术环境中,理解并掌握各类依赖管理工具的核心原理与实践技巧,结合实际项目需求适时调整策略,是提升软件开发效率和保障系统稳定性的关键所在。对于持续关注技术前沿的开发者来说,紧跟dependency management领域的最新研究成果和技术动态,无疑将助力于打造更为健壮、高效的现代化软件体系。
2023-01-31 14:37:14
71
红尘漫步_t
Nacos
...解Nacos如何实现服务间通信之后,我们发现其在现代分布式系统架构中的价值日益凸显。近期,阿里巴巴集团内部多个业务线已全面采用Nacos作为服务治理的核心组件,并在2021年的“双十一”大促中成功应对了亿级流量洪峰的挑战,验证了其在大规模微服务场景下的稳定性与可靠性。 与此同时,Nacos社区也在持续活跃发展,不断推出新功能和优化升级。例如,最新版本的Nacos不仅增强了服务发现与配置管理能力,还引入了更精细化的权限控制、动态DNS服务支持以及更深度的与Kubernetes等云原生生态系统的集成特性。这些改进进一步提升了开发者的使用体验,助力企业更好地构建云时代的微服务架构。 此外,随着Service Mesh技术的发展,Nacos也开始探索与Istio、Linkerd等Service Mesh解决方案的融合应用,旨在为用户提供统一的服务治理视角,无论是在传统的微服务架构还是新型的Service Mesh架构下,都能借助Nacos实现高效便捷的服务管理和通信。 总之,Nacos凭借其强大的服务治理能力已成为众多开发者和企业在实施微服务战略时的重要选择,而持续演进的技术创新也让Nacos在未来软件架构领域中具有更大的发展潜力和想象空间。
2023-04-20 17:45:00
99
诗和远方-t
Hibernate
《存储过程在现代微服务架构中的新角色》 随着微服务架构的兴起,数据库操作的需求变得更为复杂且分散。传统的存储过程不再仅仅是单个应用程序的专属工具,而是开始在微服务环境中扮演重要角色。例如,Netflix在其Chaos Engineering实践中,就利用存储过程实现了服务间的断路和故障注入,以测试系统的弹性。同时,由于存储过程在数据库层面执行,减少了服务间通信的开销,符合微服务架构倡导的低延迟原则。 另一个趋势是使用云原生数据库,如AWS的RDS for PostgreSQL或Google Cloud的Cloud Spanner,这些数据库支持用户自定义存储过程,进一步增强了服务的可扩展性和定制性。在这些环境下,存储过程可以作为服务之间的API接口,提供统一的业务逻辑处理,简化服务之间的协作。 存储过程在数据治理和合规性方面也有所贡献。随着GDPR等数据保护法规的实施,存储过程可以用于执行数据清洗、脱敏等操作,确保数据处理过程透明且符合法规要求。 总的来说,存储过程在微服务架构中的角色正从传统的执行点扩展到服务间的交互、数据管理和合规性保障。开发者需要重新审视和学习如何在新的技术栈中有效地利用存储过程,以适应不断演进的软件开发环境。
2024-04-30 11:22:57
520
心灵驿站
站内搜索
用于搜索本网站内部文章,支持栏目切换。
知识学习
实践的时候请根据实际情况谨慎操作。
随机学习一条linux命令:
unalias alias_name
- 删除已定义的别名。
推荐内容
推荐本栏目内的其它文章,看看还有哪些文章让你感兴趣。
2023-04-28
2023-08-09
2023-06-18
2023-04-14
2023-02-18
2023-04-17
2024-01-11
2023-10-03
2023-09-09
2023-06-13
2023-08-07
2023-03-11
历史内容
快速导航到对应月份的历史文章列表。
随便看看
拉到页底了吧,随便看看还有哪些文章你可能感兴趣。
时光飞逝
"流光容易把人抛,红了樱桃,绿了芭蕉。"