.net core 讀取本地指定目錄下的檔案
阿新 • • 發佈：2018-12-10
專案需求
asp.net core 讀取log目錄下的.log檔案，.log檔案的內容如下：
xxx.log
------------------------------------------begin--------------------------------- 寫入時間:2018-09-11 17:01:48 userid=1000 golds=10 -------------------------------------------end---------------------------------
一個 begin end 為一組，同一個.log檔案裡 userid 相同的，取寫入時間最大一組值，所需結果如下：
UserID Golds RecordDate 1001 20 2018/9/11 17:10:48 1000 20 2018/9/11 17:11:48 1003 30 2018/9/11 17:12:48 1002 10 2018/9/11 18:01:48 1001 20 2018/9/12 17:10:48 1000 30 2018/9/12 17:12:48 1002 10 2018/9/12 18:01:48
專案結構
Snai.File.FileOperation Asp.net core 2.0 網站
專案實現
新建Snai.File解決方案，在解決方案下新建一個名Snai.File.FileOperation Asp.net core 2.0 空網站
把log日誌檔案拷備到專案下
修改Startup類的ConfigureServices()方法，註冊訪問本地檔案所需的服務，到時在中介軟體中通過建構函式注入新增到中介軟體，這樣就可以在一個地方控制檔案的訪問路徑（也就是應用程式啟動的時候）
public void ConfigureServices(IServiceCollection services){ services.AddSingleton<IFileProvider>(new PhysicalFileProvider(Directory.GetCurrentDirectory()));}
新建 Middleware 資料夾，在 Middleware下新建 Entity 資料夾，新建 UserGolds.cs 類，用來儲存讀取的日誌內容，程式碼如下
namespace Snai.File.FileOperation.Middleware.Entity{ public class UserGolds { public UserGolds() { RecordDate = new DateTime(1970, 01, 01); UserID = 0; Golds = 0; } public DateTime RecordDate { get; set; } public int UserID { get; set; } public int Golds { get; set; } }}
在 Middleware 下新建 FileProviderMiddleware.cs 中介軟體類，用於讀取 log 下所有日誌檔案內容，並整理成所需的內容格式，程式碼如下
namespace Snai.File.FileOperation.Middleware{ public class FileProviderMiddleware { private readonly RequestDelegate _next; private readonly IFileProvider _fileProvider; public FileProviderMiddleware(RequestDelegate next, IFileProvider fileProvider) { _next = next; _fileProvider = fileProvider; } public async Task Invoke(HttpContext context) { var output = new StringBuilder(""); //ResolveDirectory(output, "", ""); ResolveFileInfo(output, "log", ".log"); await context.Response.WriteAsync(output.ToString()); } //讀取目錄下所有檔案內容 private void ResolveFileInfo(StringBuilder output, string path, string suffix) { output.AppendLine("UserID Golds RecordDate"); IDirectoryContents dir = _fileProvider.GetDirectoryContents(path); foreach (IFileInfo item in dir) { if (item.IsDirectory) { ResolveFileInfo(output, item.PhysicalPath.Substring(Directory.GetCurrentDirectory().Length), suffix); } else { if (item.Name.Contains(suffix)) { var userList = new List<UserGolds>(); var user = new UserGolds(); IFileInfo file = _fileProvider.GetFileInfo(path + "\\" + item.Name); using (var stream = file.CreateReadStream()) { using (var reader = new StreamReader(stream)) { string content = reader.ReadLine(); while (content != null) { if (content.Contains("begin")) { user = new UserGolds(); } if (content.Contains("寫入時間")) { DateTime recordDate; string strRecordDate = content.Substring(content.IndexOf(":") + 1).Trim(); if (DateTime.TryParse(strRecordDate, out recordDate)) { user.RecordDate = recordDate; } } if (content.Contains("userid")) { int userID; string strUserID = content.Substring(content.LastIndexOf("=") + 1).Trim(); if (int.TryParse(strUserID, out userID)) { user.UserID = userID; } } if (content.Contains("golds")) { int golds; string strGolds = content.Substring(content.LastIndexOf("=") + 1).Trim(); if (int.TryParse(strGolds, out golds)) { user.Golds = golds; } } if (content.Contains("end")) { var userMax = userList.FirstOrDefault(u => u.UserID == user.UserID); if (userMax == null || userMax.UserID <= 0) { userList.Add(user); } else if (userMax.RecordDate < user.RecordDate) { userList.Remove(userMax); userList.Add(user); } } content = reader.ReadLine(); } } } if (userList != null && userList.Count > 0) { foreach (var golds in userList.OrderBy(u => u.RecordDate)) { output.AppendLine(golds.UserID.ToString() + " " + golds.Golds + " " + golds.RecordDate); } output.AppendLine(""); } } } } } //讀取目錄下所有檔名 private void ResolveDirectory(StringBuilder output, string path, string prefix) { IDirectoryContents dir = _fileProvider.GetDirectoryContents(path); foreach (IFileInfo item in dir) { if (item.IsDirectory) { output.AppendLine(prefix + "[" + item.Name + "]"); ResolveDirectory(output, item.PhysicalPath.Substring(Directory.GetCurrentDirectory().Length), prefix + " "); } else { output.AppendLine(path + prefix + item.Name); } } } } public static class UseFileProviderExtensions { public static IApplicationBuilder UseFileProvider(this IApplicationBuilder app) { return app.UseMiddleware<FileProviderMiddleware>(); } }}
上面有兩個方法 ResolveFileInfo()和ResolveDirectory()
ResolveFileInfo() 讀取目錄下所有檔案內容，也就是需求所用的方法
ResolveDirectory() 讀取目錄下所有檔名，是輸出目錄下所有目錄和檔名，不是需求所需但也可以用
修改Startup類的Configure()方法，在app管道中使用檔案中介軟體服務
public void Configure(IApplicationBuilder app, IHostingEnvironment env){ if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); } app.UseFileProvider(); app.Run(async (context) => { await context.Response.WriteAsync("Hello World!"); });}
到此所有程式碼都已編寫完成
啟動執行專案，得到所需結果，頁面結果如下
