[翻译]创建ASP.NET WebApi RESTful 服务(9)

一旦成功的发布API后,使用者将依赖于你所提供的服务。但是变更总是无法避免的,因此谨慎的制定ASP.NET Web API的版本策略就变得非常重要。一般来说,新的功能需要无缝的接入,有时新老版本需要并行,以便给使用者足够的时间来进行迁移和配套的变更。设置,老的版本会一直持续被使用。

简单版本管理

假设我们现在对StudentsController进行修改,将GET方法中返回“FirstName” 和 “LastName”修改为返回“FullName”和 “CoursesDuration”。

最简单的方法就是新建一个类似于StudentsV2Controller的新服务。请留意V2,接下来将依赖这个引入管理策略。这种方法来自于Shawn Wildermuthplural sight course文章。旧版本的服务返回的json应该是这样的:

   1:  [{
   2:      "id": 2,
   3:      "url": "http://localhost:8323/api/students/HasanAhmad",
   4:      "firstName": "Hasan",
   5:      "lastName": "Ahmad",
   6:      "gender": 0,
   7:      "enrollmentsCount": 4
   8:  },
   9:  {
  10:      "id": 3,
  11:      "url": "http://localhost:8323/api/students/MoatasemAhmad",
  12:      "firstName": "Moatasem",
  13:      "lastName": "Ahmad",
  14:      "gender": 0,
  15:      "enrollmentsCount": 4
  16:  }]

而新版本的返回如下:

   1:  [{
   2:      "id": 2,
   3:      "url": "http://localhost:8323/api/students/HasanAhmad",
   4:      "fullName": "Hasan Ahmad",
   5:      "gender": 0,
   6:      "enrollmentsCount": 4,
   7:      "coursesDuration": 13
   8:  },
   9:  {
  10:      "id": 3,
  11:      "url": "http://localhost:8323/api/students/MoatasemAhmad",
  12:      "fullName": "Moatasem Ahmad",
  13:      "gender": 0,
  14:      "enrollmentsCount": 4,
  15:      "coursesDuration": 16
  16:  }]

新版本的GET函数的实现为:

   1:  public IEnumerable<StudentV2BaseModel> Get(int page = 0, int pageSize = 10)
   2:      {
   3:          IQueryable<Student> query;
   4:   
   5:          query = TheRepository.GetAllStudentsWithEnrollments().OrderBy(c => c.LastName);
   6:   
   7:          var totalCount = query.Count();
   8:          var totalPages = Math.Ceiling((double)totalCount / pageSize);
   9:   
  10:          var urlHelper = new UrlHelper(Request);
  11:          var prevLink = page > 0 ? urlHelper.Link("Students", new { page = page - 1, pageSize = pageSize }) : "";
  12:          var nextLink = page < totalPages - 1 ? urlHelper.Link("Students", new { page = page + 1, pageSize = pageSize }) : "";
  13:   
  14:          var paginationHeader = new
  15:          {
  16:              TotalCount = totalCount,
  17:              TotalPages = totalPages,
  18:              PrevPageLink = prevLink,
  19:              NextPageLink = nextLink
  20:          };
  21:   
  22:          System.Web.HttpContext.Current.Response.Headers.Add("X-Pagination",
  23:          Newtonsoft.Json.JsonConvert.SerializeObject(paginationHeader));
  24:   
  25:          var results = query
  26:          .Skip(pageSize * page)
  27:          .Take(pageSize)
  28:          .ToList()
  29:          .Select(s => TheModelFactory.CreateV2Summary(s));
  30:   
  31:          return results;
  32:      }

StudentV2BaseModel和CreateV2Summary只是为了举例方便,实际可以根据需要是否要进行这样的修改或者无须修改。

具体的代码如下:

   1:  public class StudentV2BaseModel
   2:      {
   3:          public int Id { get; set; }
   4:          public string Url { get; set; }
   5:          public string FullName { get; set; }
   6:          public Data.Enums.Gender Gender { get; set; }
   7:          public int EnrollmentsCount { get; set; }
   8:          public double CoursesDuration { get; set; }
   9:      }
  10:   
  11:      public class ModelFactory
  12:      {
  13:          public StudentV2BaseModel CreateV2Summary(Student student)
  14:          {
  15:              return new StudentV2BaseModel()
  16:              {
  17:                  Url = _UrlHelper.Link("Students", new { userName = student.UserName }),
  18:                  Id = student.Id,
  19:                  FullName = string.Format("{0} {1}", student.FirstName, student.LastName),
  20:                  Gender = student.Gender,
  21:                  EnrollmentsCount = student.Enrollments.Count(),
  22:                  CoursesDuration = Math.Round(student.Enrollments.Sum(c => c.Course.Duration))
  23:              };
  24:          }
  25:      }

[翻译]创建ASP.NET WebApi RESTful 服务(9),布布扣,bubuko.com

[翻译]创建ASP.NET WebApi RESTful 服务(9)

上一篇:curl网站开发指南


下一篇:网络编程之Winsock2