Delphi Tutorial

Introduction

All Apache Thrift tutorials require that you have:

  1. The Apache Thrift Compiler and Libraries, see Download and Building from Source for more details.
  2. Generated the tutorial.thrift and shared.thrift files:
    thrift -r --gen delphi tutorial.thrift
  3. Followed all prerequisites listed below.

Prerequisites

Client

program DelphiClient;

{$APPTYPE CONSOLE}
{$D 'Copyright (c) 2012 The Apache Software Foundation'}

uses
  SysUtils,
  Generics.Collections,
  Thrift in '..\..\..\lib\delphi\src\Thrift.pas',
  Thrift.Collections in '..\..\..\lib\delphi\src\Thrift.Collections.pas',
  Thrift.Configuration in '..\..\..\lib\delphi\src\Thrift.Configuration.pas',
  Thrift.Exception in '..\..\..\lib\delphi\src\Thrift.Exception.pas',
  Thrift.Utils in '..\..\..\lib\delphi\src\Thrift.Utils.pas',
  Thrift.Stream in '..\..\..\lib\delphi\src\Thrift.Stream.pas',
  Thrift.Protocol in '..\..\..\lib\delphi\src\Thrift.Protocol.pas',
  Thrift.Server in '..\..\..\lib\delphi\src\Thrift.Server.pas',
  Thrift.Transport in '..\..\..\lib\delphi\src\Thrift.Transport.pas',
  Thrift.Transport.WinHTTP in '..\..\..\lib\delphi\src\Thrift.Transport.WinHTTP.pas',
  Thrift.Transport.MsxmlHTTP in '..\..\..\lib\delphi\src\Thrift.Transport.MsxmlHTTP.pas',
  Thrift.WinHTTP in '..\..\..\lib\delphi\src\Thrift.WinHTTP.pas',
  Shared in '..\..\gen-delphi\Shared.pas',
  Tutorial in '..\..\gen-delphi\Tutorial.pas';


type
  DelphiTutorialClient = class
  public
    class procedure Main;
  end;


//--- DelphiTutorialClient ---------------------------------------


class procedure DelphiTutorialClient.Main;
var transport : ITransport;
    protocol  : IProtocol;
    client    : TCalculator.Iface;
    work      : IWork;
    sum, quotient, diff : Integer;
    log       : ISharedStruct;
begin
  try
    transport := TSocketImpl.Create( 'localhost', 9090);
    protocol  := TBinaryProtocolImpl.Create( transport);
    client    := TCalculator.TClient.Create( protocol);

    transport.Open;

    client.ping;
    WriteLn('ping()');

    sum := client.add( 1, 1);
    WriteLn( Format( '1+1=%d', [sum]));

    work := TWorkImpl.Create;

    work.Op   := TOperation.DIVIDE;
    work.Num1 := 1;
    work.Num2 := 0;
    try
      quotient := client.calculate(1, work);
      WriteLn( 'Whoa we can divide by 0');
      WriteLn( Format('1/0=%d',[quotient]));
    except
      on io: TInvalidOperation
      do WriteLn( 'Invalid operation: ' + io.Why);
    end;

    work.Op   := TOperation.SUBTRACT;
    work.Num1 := 15;
    work.Num2 := 10;
    try
      diff := client.calculate( 1, work);
      WriteLn( Format('15-10=%d', [diff]));
    except
      on io: TInvalidOperation
      do WriteLn( 'Invalid operation: ' + io.Why);
    end;

    log := client.getStruct(1);
    WriteLn( Format( 'Check log: %s', [log.Value]));

    transport.Close();

  except
    on e : Exception
    do WriteLn( e.ClassName+': '+e.Message);
  end;
end;


begin
  try
    DelphiTutorialClient.Main;
  except

Server

program DelphiServer;

{$APPTYPE CONSOLE}
{$D 'Copyright (c) 2012 The Apache Software Foundation'}

{$Q+}     // throws exceptions on numeric overflows

uses
  SysUtils,
  Generics.Collections,
  Thrift in '..\..\..\lib\delphi\src\Thrift.pas',
  Thrift.Collections in '..\..\..\lib\delphi\src\Thrift.Collections.pas',
  Thrift.Configuration in '..\..\..\lib\delphi\src\Thrift.Configuration.pas',
  Thrift.Exception in '..\..\..\lib\delphi\src\Thrift.Exception.pas',
  Thrift.Utils in '..\..\..\lib\delphi\src\Thrift.Utils.pas',
  Thrift.Stream in '..\..\..\lib\delphi\src\Thrift.Stream.pas',
  Thrift.Protocol in '..\..\..\lib\delphi\src\Thrift.Protocol.pas',
  Thrift.Server in '..\..\..\lib\delphi\src\Thrift.Server.pas',
  Thrift.Transport in '..\..\..\lib\delphi\src\Thrift.Transport.pas',
  Thrift.WinHTTP in '..\..\..\lib\delphi\src\Thrift.WinHTTP.pas',
  Shared in '..\..\gen-delphi\Shared.pas',
  Tutorial in '..\..\gen-delphi\Tutorial.pas';


type
  TCalculatorHandler = class( TInterfacedObject, TCalculator.Iface)
  protected
    FLog : TDictionary< Integer, ISharedStruct>;

    // TSharedService.Iface
    function  getStruct(key: Integer): ISharedStruct;

    // TCalculator.Iface
    procedure ping();
    function  add(num1: Integer; num2: Integer): Integer;
    function  calculate(logid: Integer; const w: IWork): Integer;
    procedure zip();

  public
    constructor Create;
    destructor Destroy;  override;

  end;

  DelphiTutorialServer = class
  public
    class procedure Main;
  end;


//--- TCalculatorHandler ---------------------------------------------------


constructor TCalculatorHandler.Create;
begin
  inherited Create;
  FLog := TDictionary< Integer, ISharedStruct>.Create();
end;


destructor TCalculatorHandler.Destroy;
begin
  try
    FreeAndNil( FLog);
  finally
    inherited Destroy;
  end;
end;


procedure TCalculatorHandler.ping;
begin
  WriteLn( 'ping()');
end;


function TCalculatorHandler.add(num1: Integer; num2: Integer): Integer;
begin
  WriteLn( Format( 'add( %d, %d)', [num1, num2]));
  result := num1 + num2;
end;


function TCalculatorHandler.calculate(logid: Integer; const w: IWork): Integer;
var entry : ISharedStruct;
begin
  try
    WriteLn( Format('calculate( %d, [%d,%d,%d])', [logid, Ord(w.Op), w.Num1, w.Num2]));

    case w.Op of
      TOperation.ADD      :  result := w.Num1 + w.Num2;
      TOperation.SUBTRACT :  result := w.Num1 - w.Num2;
      TOperation.MULTIPLY :  result := w.Num1 * w.Num2;
      TOperation.DIVIDE   :  result := Round( w.Num1 / w.Num2);
    else
      raise TInvalidOperation.Create( Ord(w.Op), 'Unknown operation');
    end;

  except
    on e:Thrift.TException do raise;  // let Thrift Exceptions pass through
    on e:Exception do raise TInvalidOperation.Create( Ord(w.Op), e.Message);  // repackage all other
  end;

  entry := TSharedStructImpl.Create;
  entry.Key   := logid;
  entry.Value := IntToStr( result);
  FLog.AddOrSetValue( logid, entry);
end;


function TCalculatorHandler.getStruct(key: Integer): ISharedStruct;
begin
  WriteLn( Format( 'getStruct(%d)', [key]));
  result := FLog[key];
end;


procedure TCalculatorHandler.zip;
begin
  WriteLn( 'zip()');
end;


//--- DelphiTutorialServer ----------------------------------------------------------------------


class procedure DelphiTutorialServer.Main;
var handler   : TCalculator.Iface;
    processor : IProcessor;
    transport : IServerTransport;
    server    : IServer;
begin
  try
    handler   := TCalculatorHandler.Create;
    processor := TCalculator.TProcessorImpl.Create( handler);
    transport := TServerSocketImpl.Create( 9090);
    server    := TSimpleServer.Create( processor, transport);

    WriteLn( 'Starting the server...');
    server.Serve();

  except
    on e: Exception do WriteLn( e.Message);
  end;

  WriteLn('done.');
end;


begin
  try
    DelphiTutorialServer.Main;
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);

Additional Information