C# WebAPI 插件热插拔

背景

WebAPI 插件热插拔是指在不重启应用程序的情况下,能够动态地加载、更新或卸载功能模块(即插件)的能力。这种设计模式在软件开发中非常有用,尤其是在需要频繁更新或扩展功能的大型系统中。通过实现插件架构,可以将系统的不同部分解耦,使得它们可以独立开发、测试和部署。

对于WebAPI来说,这意味着服务端可以在运行时根据业务需求灵活调整其提供的API接口和服务逻辑,而无需担心每次修改都要重新启动整个应用,从而减少停机时间,提高系统的稳定性和灵活性。

程序演示

我们启动程序通过调用动态接口使用插件的增删改查等功能;,其中带{DynamicParam}的是你要使用的插件的名称;{funName}是你要使用插件的接口名称。

程序运行界面

 

 

查询筛选接口

使用postman 进行查询筛选博客操作

 

 

 

 

插件新增接口

插件的新增博客接口,然后看数据库变化

 

 

 

 

 

 

插件更新接口

插件的更新博客接口

 

 

 

插件删除接口

 

 

插件上传文件接口

 

代码实现

前提准备

需要安装nuget程序包:Newtonsoft.Json,SqlSugarCore。方便我们做类型转换和数据存储的相关功能;

1,首先我们创建一个webapi 的项目,然后定义一个插件IPluginDllApi.cs的接口(后续新增的类库需要继承用)

using Microsoft.AspNetCore.Mvc;
namespace DynamicPluginApiDemo.Utils
{
 public interface IPluginDllApi
 {
 string Name { get; }
 IActionResult GetRequest(string funName, Dictionary<string, string> queryParameters);
 IActionResult PostRequestForm(string funName, Dictionary<string, string> queryParameters, IFormCollection formData);
 IActionResult PostRequestBody(string funName, Dictionary<string, string> queryParameters, object jsonData);
 }
}

2,创建一个插件帮助类和数据库帮助类。

using SqlSugar;
namespace DynamicPluginApiDemo.Utils
{
 public static class DbHelper
 {
 public static SqlSugarClient Db;
 static DbHelper()
 {
 if (Db == null)
 //创建数据库对象 (用法和EF Dappper一样通过new保证线程安全)
 Db = new SqlSugarClient(new ConnectionConfig()
 {
 ConnectionString = "server=192.168.1.61;Database=testdb;Uid=root;Pwd=MyNewPass@123;SslMode=None;AllowPublicKeyRetrieval=true;",
 DbType = SqlSugar.DbType.MySql,
 IsAutoCloseConnection = true
 },
 db =>
 {
 db.Aop.OnLogExecuting = (sql, pars) =>
 {
 //获取原生SQL推荐 5.1.4.63 性能OK
 Console.WriteLine(UtilMethods.GetNativeSql(sql, pars));
 };
 });
 }
 }
}
using System.Runtime.Loader;
namespace DynamicPluginApiDemo.Utils
{
 public class PluginDllHelper
 {
 public static List<IPluginDllApi> _labPlugins = new List<IPluginDllApi>();
 private static string _pluginFolder = Path.Combine(Directory.GetCurrentDirectory(), "Plugins");
 /// <summary>
 /// 重新加载
 /// </summary>
 public static void ReLoadDll()
 {
 if (!Directory.Exists(_pluginFolder))
 Directory.CreateDirectory(_pluginFolder);
 _labPlugins = new List<IPluginDllApi>();
 foreach (var dllPath in Directory.GetFiles(_pluginFolder, "*.dll"))
 {
 try
 {
 var assemblyLoadContext = new AssemblyLoadContext(Path.GetFileNameWithoutExtension(dllPath), true);
 var assembly = assemblyLoadContext.LoadFromAssemblyPath(dllPath);
 var pluginTypes = assembly.GetTypes()
 .Where(t => typeof(IPluginDllApi).IsAssignableFrom(t) && !t.IsInterface && !t.IsAbstract);
 foreach (var pluginType in pluginTypes)
 {
 if (Activator.CreateInstance(pluginType) is IPluginDllApi pluginInstance)
 {
 if (pluginInstance != null)
 _labPlugins.Add((pluginInstance));
 }
 }
 }
 catch (Exception ex)
 {
 Console.WriteLine($"Failed to load assembly {dllPath}: {ex.Message}");
 }
 }
 }
 }
}

3,然后我们在程序启动的时候进行调用

 

 4,接下来我们创建一个PluginController.cs控制器,这个控制器实现了动态的路由。代码如下:

using DynamicPluginApiDemo.Utils;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Newtonsoft.Json.Linq;
namespace DynamicPluginApiDemo.Controllers
{
 [Route("api/[controller]/{DynamicParam}")]
 [ApiController]
 public class PluginController : ControllerBase
 {
 /// <summary>
 /// 动态插件的名称
 /// </summary>
 private readonly string _dynamicParam = string.Empty;
 public PluginController(IHttpContextAccessor httpContextAccessor)
 {
 var dynamicParamKey = httpContextAccessor?.HttpContext?.GetRouteValue("DynamicParam");
 if (dynamicParamKey != null)
 _dynamicParam = dynamicParamKey?.ToString() ?? string.Empty;
 }
 // GET: api/ApifulPlugin/apidll/GetRequest/Query?SearchName=AAA
 [HttpGet("GetRequest/{functionName}")]
 public IActionResult GetRequest(string functionName, [FromQuery] Dictionary<string, string> queryParameters)
 {
 var instance = PluginDllHelper._labPlugins.FirstOrDefault(x => x.Name == _dynamicParam);
 if (instance == null)
 return NotFound();
 return instance.GetRequest(functionName, queryParameters);
 }
 // POST: api/Dynamic/json
 // Receives query parameters and JSON body
 [HttpPost("PostRequestBody/{functionName}")]
 public IActionResult PostRequestBody(string functionName, [FromQuery] Dictionary<string, string> queryParameters, [FromBody] object jsonData)
 {
 var instance = PluginDllHelper._labPlugins.FirstOrDefault(x => x.Name == _dynamicParam);
 if (instance == null)
 return NotFound();
 return instance.PostRequestBody(functionName, queryParameters, jsonData);
 }
 // POST: api/Dynamic/form
 [HttpPost("PostRequestForm/{functionName}")]
 public IActionResult PostRequestForm(string functionName, [FromQuery] Dictionary<string, string> queryParameters, IFormCollection formData)
 {
 var instance = PluginDllHelper._labPlugins.FirstOrDefault(x => x.Name == _dynamicParam);
 if (instance == null)
 return NotFound();
 return instance.PostRequestForm(functionName, queryParameters, formData);
 }
 }
}

5,webapi项目的内容差不多了。接下来我们创建一个类库项目,名字叫做BlogPluginApi。然后项目引用一下主项目,并且创建一个BlogPluginApi.cs文件继承主项目的IPluginDllApi。

using BlogPluginApi.Service;
using DynamicPluginApiDemo.Utils;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using Microsoft.SqlServer.Server;
namespace BlogPluginApi
{
 public class BlogPluginApi : IPluginDllApi
 {
 public string Name => "BlogPluginApi";
 public IActionResult GetRequest(string funName, Dictionary<string, string> queryParameters)
 {
 var result = string.Empty;
 switch (funName)
 {
 case "Query":
 result = BlogService.Query(queryParameters);
 break;
 }
 return new ContentResult
 {
 StatusCode = 200,
 ContentType = "text/plain",
 Content = result
 };
 }
 public IActionResult PostRequestBody(string funName, Dictionary<string, string> queryParameters, object jsonData)
 {
 var result = string.Empty;
 switch (funName)
 {
 case "Save":
 result = BlogService.Save(jsonData);
 break;
 case "Update":
 result = BlogService.Update(jsonData);
 break;
 case "Delete":
 result = BlogService.Delete(jsonData);
 break;
 }
 return new ContentResult
 {
 StatusCode = 200,
 ContentType = "text/plain",
 Content = result
 };
 }
 public IActionResult PostRequestForm(string funName, Dictionary<string, string> queryParameters, IFormCollection formData)
 {
 var result = string.Empty;
 switch (funName)
 {
 case "UploadFile":
 result = BlogService.UploadFile(queryParameters, formData);
 break;
 }
 return new ContentResult
 {
 StatusCode = 200,
 ContentType = "text/plain",
 Content = result
 };
 }
 }
}

6,然后我们增加blog表的实体,服务,模型等。当然这些可以放在主项目中,通过项目引用使用主项目的代码。

 

using SqlSugar;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BlogPluginApi.Entitys.Blogs
{
 [SugarTable("BLOG", TableDescription = "博客")]
 public class Blog
 {
 [SugarColumn(ColumnName = "ID", IsIdentity = true, IsPrimaryKey = true)]
 public int Id { get; set; }
 [SugarColumn(ColumnName = "Title")]
 public string Title { get; set; }
 [SugarColumn(ColumnName = "Context")]
 public string Context { get; set; }
 [SugarColumn(ColumnName = "UserId")]
 public int UserId { get; set; }
 [SugarColumn(ColumnName = "CreateTime")]
 public DateTime CreateTime { get; set; }
 }
}
using SqlSugar;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BlogPluginApi.Models.Blogs
{
 public class BlogInputDto
 {
 public int? Id { get; set; }
 public string? Title { get; set; }
 public string? Context { get; set; }
 public int? UserId { get; set; }
 public DateTime? CreateTime { get; set; }
 }
}
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BlogPluginApi.Models.Blogs
{
 public class SearchDto
 {
 public string SearchName { get; set; }
 }
}
using AutoMapper;
using BlogPluginApi.Entitys.Blogs;
using BlogPluginApi.Models.Blogs;
using DynamicPluginApiDemo.Utils;
using Microsoft.AspNetCore.Http;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace BlogPluginApi.Service
{
 public static class BlogService
 {
 public static string Query(Dictionary<string, string> queryParameters)
 {
 SearchDto searchBlogDto = new SearchDto();
 if (queryParameters.TryGetValue("SearchName", out var searchName))
 {
 searchBlogDto.SearchName = searchName;
 }
 var result = string.Join(",", DbHelper.Db.Queryable<Blog>().Select(s => s.Title).ToList());
 return result;
 }
 public static string Delete(object param)
 {
 var strParam = param.ToString();
 if (string.IsNullOrEmpty(strParam)) return string.Empty;
 var deleteIds = JsonConvert.DeserializeObject<List<int>>(strParam);
 if (deleteIds != null)
 {
 var count = DbHelper.Db.Deleteable<Blog>().Where(x => deleteIds.Contains(x.Id)).ExecuteCommand();
 return count.ToString();
 }
 return string.Empty;
 }
 public static string Save(object param)
 {
 var strParam = param.ToString();
 if (string.IsNullOrEmpty(strParam)) return string.Empty;
 var inputDto = JsonConvert.DeserializeObject<Blog>(strParam);
 if (inputDto != null)
 {
 var count = DbHelper.Db.Insertable(inputDto).ExecuteCommand();
 }
 return "success";
 }
 public static string Update(object param)
 {
 var strParam = param.ToString();
 if (string.IsNullOrEmpty(strParam)) return string.Empty;
 var inputDto = JsonConvert.DeserializeObject<Blog>(strParam);
 if (inputDto != null)
 {
 var count = DbHelper.Db.Updateable(inputDto).ExecuteCommand();
 }
 return "success";
 }
 public static string UploadFile(Dictionary<string, string> queryParameters, IFormCollection formData)
 {
 string UploadId = string.Empty;
 if (queryParameters.TryGetValue("uploadId", out var uploadId))
 {
 UploadId = uploadId;
 }
 var file = formData.Files.FirstOrDefault();
 if (file != null)
 return file.FileName;
 return string.Empty;
 }
 }
}

 7,然后我们生成一下BlogPluginApi项目,把生成的dll文件放在放在主项目的Plugins文件夹下就可以了。

 注意:

系统必须被设计为能够识别和管理不同的插件版本,并且能够在运行时安全地切换这些版本。

结语

Web API插件的热插拔是一个复杂但非常有价值的功能,它不仅提高了系统的灵活性和可用性,还增强了用户体验。通过精心规划和技术实践,可以使这一特性成为现代Web应用和服务的一个亮点。

作者:黄金程序员原文地址:https://www.cnblogs.com/BFMC/p/18687474

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