delphi 自学RTC RealThinClient 1-6

自学RTC——ServerLesson1

RTC全称RealThinClient，据说是Delphi做三层的神器之一，虽然听说已久，却始终未好好研究过，而且安装包里带的有示例源码，于是乎，索性拿这些源码开这么个系列，督促下自己。

步骤

创建一个新工程

从RTC Server组件页中找到RtcHttpServer组件放到窗体上

设置RtcHttpServer1的ServerPort属性为80

在窗体的OnCreate事件里写上代码：

RtcHttpServer1.Listen;

从RTC Server组件页中找到RtcDataProvider组件放到窗体上

设置RtcDataProvider1的Server属性为RtcHttpServer1

在RtcDataProvider1的OnCheckRequest事件中写上代码：

with Sender as TRtcDataServer do

  if UpperCase(Request.FileName)='/TIME' then

    Accept;

在RtcDataProvider1的OnDataReceived事件中写上代码：

with Sender as TRtcDataServer do

  if Request.Complete then

    Write('Current time is: '+TimeToStr(Now));

编译并运行

打开浏览器，访问网址http://localhost/time

示例源码

核心源码

procedure TForm1.RtcDataProvider1CheckRequest(Sender: TRtcConnection);

  begin

  with Sender as TRtcDataServer do

    if Request.FilePath.Equal(0,'TIME') then

      Accept;

  end;

procedure TForm1.RtcDataProvider1DataReceived(Sender: TRtcConnection);

  var

    a:integer;

  begin

  with Sender as TRtcDataServer do

    if Request.Complete then

      begin

      Write('

      Write('Request from '+Sender.PeerAddr+':'+Sender.PeerPort+'
');

      Write('Server time: '+TimeToStr(Now)+'
');

      Write('
URL = '+Request.URL+'
');

      Write('
URI = '+Request.URI+'
');

      Write('
FileName = '+Request.FileName+'
');

      Write('
FilePath.Count = '+IntToStr(Request.FilePath.Count)+'
');

      for a:=0 to Request.FilePath.Count-1 do

        Write('FilePath['+IntToStr(a)+'] = "'+Request.FilePath[a]+'"
');

      Write('
Query.ItemCount = '+IntToStr(Request.Query.ItemCount)+'
');

      for a:=0 to Request.Query.ItemCount-1 do

        Write('Query Item '+IntToStr(a)+': '+

              'Name = "'+Request.Query.ItemName[a]+'"; '+

              'Value = "'+Request.Query.ItemValue[a]+'"
');

      Write('');

      end;

  end;

测试

浏览器访问http://localhost/time：

Request from 127.0.0.1:60623

Server time: 21:12:30

URL = localhost/time

URI = /time

FileName = /time

FilePath.Count = 1

FilePath[0] = "time"

Query.ItemCount = 0

浏览器访问http://localhost/times：

返回错误

浏览器访问http://localhost/time/test/abc：

Request from 127.0.0.1:60704

Server time: 21:22:32

URL = localhost/time/test/abc

URI = /time/test/abc

FileName = /time/test/abc

FilePath.Count = 3

FilePath[0] = "time"

FilePath[1] = "test"

FilePath[2] = "abc"

Query.ItemCount = 0

浏览器访问http://localhost/time?test=abc：

Request from 127.0.0.1:60725

Server time: 21:24:06

URL = localhost/time?test=abc

URI = /time?test=abc

FileName = /time

FilePath.Count = 1

FilePath[0] = "time"

Query.ItemCount = 1

Query Item 0: Name = "test"; Value = "abc"

源码解读

Request.FilePath.Equal(0,'TIME') VS UpperCase(Request.FileName)='/TIME'

从响应结果可以看出：

两者都忽略了大小写

两者都不能响应/times

前者可以响应以/time开头的所有请求，并且把请求分解后放在FilePath[]里；后者则只能响应/time

两者都能响应带参数的/time

自学RTC——ServerLesson2

打开上节的工程

添加组件RtcDataProvider2并设置Server属性为RtcHttpServer1

在RtcDataProvider2的OnCheckRequest事件中写上代码：

with TRtcDataServer(Sender) do

  if UpperCase(Request.FileName)='/SQUARE' then

    Accept;

在RtcDataProvider2的OnDataReceived事件中写上代码：

var

  line:integer;

begin

with TRtcDataServer(Sender) do

  if Request.Complete then

    begin

    Write('

    Write('Here comes a table of square values ...
');

    for line:=1 to 100 do

      begin

      // 使用3个 write 和使用1个效果是一样的

      Write('Square of '+IntToStr(line)+' = ');

      Write(IntToStr(line*line));

      Write('
');

      end;

    Write('......... done.');

    Write('');

    end;

end;

编译并运行

打开浏览器，分别访问网址http://localhost/square、http://localhost/time

细节

TRtcDataProvider只响应自己接收的请求，互不干涉

TRtcDataServer(Sender) VS Sender as TRtcDataServer，考察下as与强转的效果和区别

使用多个write()与使用一个效果一样

带参数的/SQUARE

修改RtcDataProvider2的OnDataReceived事件的代码为：

var

  cnt,line:integer;

begin

with TRtcDataServer(Sender) do

  if Request.Complete then

    begin

    Write('

    Write('Here comes a table of square values ...
');

    cnt:=0;

    if Request.Query['cnt']<>'' then

      try

        cnt:=StrToInt(Request.Query['cnt']);

      except

      end;

    if (cnt

      begin

      cnt:=10;

      Write('Wrong "cnt" parameter.');

      Write('Using default value of 10.
');

      end;

    for line:=1 to cnt do

      begin

      Write('Square of '+IntToStr(line)+' = '+IntToStr(line*line));

      Write('
');

      end;

    Write('......... done.');

    Write('');

    end;

end;

编译并运行

打开浏览器，分别访问网址http://localhost/square、http://localhost/square?cnt=30、http://localhost/square?cnt=5392

自学RTC——ServerLesson3

打开上节的工程

添加组件RtcDataProvider3并设置Server属性为RtcHttpServer1，设置CheckOrder属性为900，使得RtcDataProvider3所处理的请求在其它请求之后（CheckOrder越小越先处理）

在当前exe所在路径下创建一个data文件夹，并在该文件夹内新建一个有内容的test.txt，然后编写一个GetFullFileName函数，用于从请求中提取文件名并转化为本地文件名

function GetFullFileName(fname: string): string;

var

  DocRoot: string;

begin

  DocRoot := ExtractFilePath(AppFileName);

  if Copy(DocRoot, length(DocRoot), 1) = '\' then

    Delete(DocRoot, length(DocRoot), 1);

  DocRoot := DocRoot + '\data';

  fname := StringReplace(fname, '/', '\', [rfreplaceall]);

  Result := ExpandFileName(DocRoot + fname);

  if UpperCase(Copy(Result, 1, length(DocRoot))) <> UpperCase(DocRoot) then

    Result := '';

end;

在RtcDataProvider3的OnCheckRequest事件中写上代码：

var

  fname: string;

begin

  with TRtcDataServer(Sender) do

  begin

    fname := GetFullFileName(Request.FileName);

    if (fname <> '') and (File_Exists(fname)) then

    begin

      Accept;

      Request.Info['fname'] := fname;

    end;

  end;

end;

在RtcDataProvider3的OnDataReceived事件中写上代码：

procedure TForm1.RtcDataProvider3DataReceived(Sender: TRtcConnection);

var

  fname: string;

begin

  with TRtcDataServer(Sender) do

    if Request.Complete then

    begin

      fname := Request.Info['fname'];

      if File_Exists(fname) then

        Write(Read_File(fname))

      else

        Write;

    end;

end;

编译并运行

打开浏览器，访问网址

http://localhost/test.txt

自学RTC——ServerLesson4

对于上节的示例中，比较适合发送小文件，若直接用于发送大文件的话，很容易把服务器的内存资源耗尽。当请求大文件时，可以限制每次发送大文件时使用的内存大小（例如16000 B）。

打开上节的工程

修改RtcDataProvider3的OnCheckRequest事件：

var

  fname: string;

begin

  with TRtcDataServer(Sender) do

  begin

    fname := GetFullFileName(Request.FileName);

    if (fname <> '') and (File_Exists(fname)) then

    begin

      Accept;

      Request.Info['fname'] := fname;

      Response.ContentLength := File_Size(fname);

      WriteHeader;

    end;

  end;

end;

修改RtcDataProvider3的OnDataReceived事件：

var

  fname: string;

  len: cardinal;

begin

  with TRtcDataServer(Sender) do

    if Request.Complete then

    begin

      if Response.ContentLength > Response.ContentOut then

      begin

        fname := Request.Info['fname'];

        if File_Size(fname) = Response.ContentLength then

        begin

          len := Response.ContentLength - Response.ContentOut;

          if len > 16000 then

            len := 16000;

          Write(Read_File(fname, Response.ContentOut, len));

        end

        else

          Disconnect;

      end;

    end;

end;

关联RtcDataProvider3的OnDataSent事件到OnDataReceived事件的实现，使两个事件都指向同一段代码

编译并运行

在data文件夹下放入一个大文件（例如test.mp3），访问网址http://localhost/test.mp3

流程分析

为了更进一步了解整个过程，把RtcHttpServer1和RtcDataProvider3的每个事件都记录进日志：

[22:36:08.272] RtcHttpServer1ListenStart->

[22:36:08.292] RtcDataProvider3ListenStart->

[22:36:26.108] RtcHttpServer1ClientConnect->

[22:36:26.118] RtcHttpServer1Connecting->

[22:36:26.130] RtcHttpServer1Connect->

[22:36:26.160] RtcHttpServer1DataIn->

[22:36:26.164] RtcDataProvider3CheckRequest->请求文件：F:\RTC\bin\data\test.ppt [12521984 B]

[22:36:26.169] RtcHttpServer1RequestAccepted->

[22:36:26.175] RtcDataProvider3DataOut->

[22:36:26.178] RtcHttpServer1DataOut->

[22:36:26.257] RtcHttpServer1PeekRequest->

[22:36:26.262] RtcDataProvider3DataReceived->剩余：12521984 B

[22:36:26.276] RtcDataProvider3DataOut->

[22:36:26.281] RtcHttpServer1DataOut->

[22:36:26.286] RtcDataProvider3DataSent->剩余：12505984 B

[22:36:26.301] RtcDataProvider3DataOut->

[22:36:26.311] RtcHttpServer1DataOut->

[22:36:26.316] RtcDataProvider3ReadyToSend->

[22:36:26.323] RtcDataProvider3DataSent->剩余：12489984 B

[22:36:26.338] RtcDataProvider3DataOut->

[22:36:26.345] RtcHttpServer1DataOut->

...

[22:36:50.488] RtcDataProvider3ReadyToSend->

[22:36:50.494] RtcDataProvider3DataSent->剩余：9984 B

[22:36:50.507] RtcDataProvider3DataOut->

[22:36:50.515] RtcHttpServer1DataOut->

[22:36:50.522] RtcDataProvider3ReadyToSend->

[22:36:50.528] RtcDataProvider3DataSent->

[22:36:50.534] RtcDataProvider3ResponseDone->

[22:36:50.540] RtcHttpServer1ResponseDone->

[22:38:45.919] RtcHttpServer1Disconnecting->

[22:38:45.950] RtcHttpServer1Disconnect->

[22:38:45.968] RtcHttpServer1ClientDisconnect->

[22:46:04.945] RtcDataProvider1ListenStop->

[22:46:04.955] RtcHttpServer1ListenStop->

服务端启动，RtcHttpServer1开始监听，RtcDataProvider3随着也开始监听

在浏览器中请求文件，RtcHttpServer1收到客户端的连接，RtcHttpServer1开始连接，连接成功，RtcHttpServer1收到数据（请求），RtcDataProvider3也收到请求

RtcDataProvider3在OnCheckRequest事件中检查请求，文件存在，接受请求

RtcHttpServer1确定请求被接受，RtcDataProvider3把文件名写入请求信息Request.Info['fname']中备用，把文件大小写入到响应长度Response.ContentLength里，然后把响应头发送出去（实际是发送给RtcHttpServer1，然后RtcHttpServer1把响应最终发出）

RtcHttpServer1Peek请求，RtcDataProvider3触发OnDataReceived事件

RtcDataProvider3接收到完整的请求后才进行处理，文件未发现修改（大小未改变）且文件超过16000 B，只发送16000 B（发给RtcHttpServer1，RtcHttpServer1再转发）

RtcDataProvider3数据发出，触发OnDataSent事件，事件处理中发现文件未发完，准备数据继续发送（依然是只发送16000 B，由RtcHttpServer1转发），发送后又触发OnDataSent事件……

直到文件数据全部发送完，RtcDataProvider3完成响应，RtcHttpServer1也完成响应

浏览器关闭，RtcHttpServer1开始断开连接，连接断开

关闭服务端，RtcDataProvider3停止监听，RtcHttpServer1也停止监听

自学RTC——BrowserUpload

核心代码

OnCheckRequest事件中的代码：

with TRtcDataServer(Sender) do

  if Request.FilePath.Equal(0, 'UPLOAD') then

    Accept;

OnDataReceived事件中的代码：

var

  fname: string;

  cnt: integer;

begin

  with TRtcDataServer(Sender) do

  begin

    if Request.Method = 'GET' then

    begin

      Write('

      Write('Type some text, if you like:
');

      Write('
');

      Write('Please specify a single file to upload:
');

      Write('
');

      Write('Please specify one or more files to upload:
');

      Write('
');

      Write('');

      Write('');

    end

    else

    begin

      Request.Params.AddText(Read);

      if Request.Complete then

      begin

        Write('

        if Request.Params['textline'] <> '' then

          Write('You typed this text:
' + Request.Params['textline'] + '

');

        // Uploading a single file ...

        if Request.Params.IsFile('onefile') then

        begin

          if not DirectoryExists(eUploadFolder.Text) then

            CreateDir(eUploadFolder.Text);

          fname := Request.Params['onefile'];

          if Request.Params.GetFile('onefile', eUploadFolder.Text + '\' +

            ExtractFileName(fname)) then

            Write('File "' + fname + '" was uploaded using the "single file" field.
')

          else

            Write('Error receiving File "' + fname + '".
');

        end

        else

          Write('Single file was NOT uploaded (OneFile parameter empty)
.');

        // Uploading one or more files ...

        if Request.Params.IsFile('morefiles') then

        begin

          if not DirectoryExists(eUploadFolder.Text) then

            CreateDir(eUploadFolder.Text);

          for cnt := 0 to Request.Params.ElementCount['morefiles'] - 1 do

          begin

            fname := Request.Params.Element['morefiles', cnt];

            if Request.Params.GetFile('morefiles', eUploadFolder.Text + '\' +

              ExtractFileName(fname), cnt) then

              Write('File "' + fname +

                '" was uploaded using the "more files" field at [' + IntToStr(cnt)

                + '].
')

            else

              Write('Error receiving File "' + fname + '".
');

          end;

        end

        else

          Write('Multiple files were NOT uploaded (MoreFiles parameter empty).');

        Write('');

      end;

    end;

  end;

end;

RTC组件关系图

自学RTC——DualServer

在窗体上放4个TRtcHttpServer，依次设置ServerPort为：80、443、8080和8090，并分别命名为HS80、HS443、HS8080和HS8090

再放3个TRtcDualDataServerLink到窗体上，分别命名为DL80and443、DL8080and8090和DLall

设置DL80and443的Server属性为HS80，Server2属性为HS443；设置DL8080and8090的Server属性为HS8080，Server2属性为HS8090

设置DLall的Link属性为DL80and443，Link2属性为DL8080and8090

再放1个TRtcDataProvider到窗体上，设置Link属性为DLall，并在OnCheckRequest事件里写上代码：

with TRtcDataServer(Sender) do

begin

  Accept;

  Write('you are on Server ' + ServerPort);

end;

在窗口OnShow事件里启动所有TRtcHttpServer，在OnClose事件里停止所有TRtcHttpServer

编译运行

在浏览器里分别访问http://localhost:80、http://localhost:443、http://localhost:8080、http://localhost:8090

注意：TRtcDualDataServerLink只能选择设置Server*或Link*！

感谢：超级无敌大懒虫原创分享

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