SAP NetWeaver RFC library

This cross-platform library allows you to call SAP NetWeaver RFC functions from .NET 5, .NET Core and the .NET Framework.

The library is fully tested and production ready. Supported operating systems are Windows, Linux and macOS.

Also supports connection pooling for more complex applications, see below.

Get it on NuGet

dotnet add package SapNwRfc

PM> Install-Package SapNwRfc

Prerequisites

This library requires the SAP NetWeaver RFC Library 7.50 SDK C++ binaries that should be installed locally. For download and installation instructions see SAP Note 2573790.

You can either place the DLL's in your project output folder or put them in a folder available in the systems PATH (Windows), LD_LIBRARY_PATH (Linux) or DYLD_LIBRARY_PATH (macOS) environment variable.

On Windows, the 7.50 version of the SAP binaries also require you to install the 64-bit version of the Visual C++ 2013 Redistributable package which can be downloaded and installed from here.

MacOSX and DYLD_LIBRARY_PATH

When your application is started as a child-process (f.e. when running it using Visual Studio for Mac), it is possible that the DYLD_LIBRARY_PATH is not forwarded to the child-process. This is because of this runtime protection Apple has added to OSX.

The simplest solution to this problem is to make sure the SAP binaries are placed in the working directory of your application.

or to use the NativeLibrary.SetDllImportResolver method in your application.

A more flexible workaround is to set the import resolver for the SapLibrary using the SetDllImportResolver-method like this:

NativeLibrary.SetDllImportResolver(
    assembly: typeof(SapLibrary).Assembly,
    resolver: (string libraryName, Assembly assembly, DllImportSearchPath? searchPath) =>
    {
        if (libraryName == "sapnwrfc")
        {
            NativeLibrary.TryLoad(
                libraryPath: Path.Combine("<your_sap_rfc_binaries_path>", libraryName),
                handle: out IntPtr handle);

            return handle;
        }

        return IntPtr.Zero;
    });

Usage

Connect with SAP NetWeaver

string connectionString = "AppServerHost=MY_SERVER_HOST; SystemNumber=00; User=MY_SAP_USER; Password=SECRET; Client=100; Language=EN; PoolSize=5; Trace=8";

using var connection = new SapConnection(connectionString);
connection.Connect();

Call function without input or output parameters

using var someFunction = connection.CreateFunction("BAPI_SOME_FUNCTION_NAME");
someFunction.Invoke();

Call function with input parameters but no output parameters

class SomeFunctionParameters
{
    [SapName("SOME_FIELD")]
    public string SomeField { get; set; }
}

using var someFunction = connection.CreateFunction("BAPI_SOME_FUNCTION_NAME");
someFunction.Invoke(new SomeFunctionParameters
{
    SomeField = "Some value",
});

Call function with input and output parameters

class SomeFunctionParameters
{
    [SapName("SOME_FIELD")]
    public string SomeField { get; set; }
}

class SomeFunctionResult
{
    [SapName("RES_ABC")]
    public string Abc { get; set; }
}

using var someFunction = connection.CreateFunction("BAPI_SOME_FUNCTION_NAME");
var result = someFunction.Invoke<SomeFunctionResult>(new SomeFunctionParameters
{
    SomeField = "Some value",
});

// Do something with result.Abc

Define models with a nested structure

class SomeFunctionResult
{
    [SapName("RES_ABC")]
    public string Abc { get; set; }

    [SapName("RES_ADDR")]
    public SomeFunctionResultItem Address { get; set; }
}

class SomeFunctionResultAddress
{
    [SapName("STREET")]
    public string Street { get; set; }

    [SapName("NR")]
    public string Number { get; set; }
}

Define models with a nested table

class SomeFunctionResult
{
    [SapName("RES_ABC")]
    public string Abc { get; set; }

    [SapName("RES_ITEMS")]
    public SomeFunctionResultItem[] Items { get; set; }
}

class SomeFunctionResultItem
{
    [SapName("ITM_NAME")]
    public string Name { get; set; }
}

Define models with an IEnumerable

class SomeFunctionResult
{
    [SapName("RES_ITEMS")]
    public IEnumerable<SomeFunctionResultItem> Items { get; set; }
}

class SomeFunctionResultItem
{
    [SapName("ITM_NAME")]
    public string Name { get; set; }
}

Exclude properties from mapping

class SomeFunctionParameters
{
    [SapIgnore]
    public string IgnoredProperty { get; set; }

    [SapName("SOME_FIELD")]
    public string SomeField { get; set; }
}

class SomeFunctionResult
{
    [SapIgnore]
    public string IgnoredProperty { get; set; }

    [SapName("SOME_FIELD")]
    public string SomeField { get; set; }
}

RFC Server Generic Handler

string connectionString = "AppServerHost=MY_SERVER_HOST; SystemNumber=00; User=MY_SAP_USER; Password=SECRET; Client=100; Language=EN; PoolSize=5; Trace=8";

SapServer.InstallGenericServerFunctionHandler(connectionString, (connection, function) =>
{
    var attributes = connection.GetAttributes();

    switch (function.GetName())
    {
        case "BAPI_SOME_FUNCTION_NAME":
            var parameters = function.GetParameters<SomeFunctionParameters>();
            function.SetResult(new SomeFunctionResult { Abc = "Some Value" });
        break;
    }
});

RFC Server

string connectionString = "GWHOST=MY_GW_HOST; GWSERV=MY_GW_SERV; PROGRAM_ID=MY_PROGRAM_ID; REG_COUNT=1";

using var server = SapServer.Create(connectionString);
server.Error += (object sender, SapServerErrorEventArgs args) => Console.WriteLine(args.Error.Message);
server.StateChange += (object sender, SapServerStateChangeEventArgs args) => Console.WriteLine(args.OldState + " -> " + args.NewState);
server.Launch();

Type Metadata

var typeMetadata = connection.GetTypeMetadata("MY_STRUCTURE");
var typeName = typeMetadata.GetTypeName();
var fieldCount = typeMetadata.Fields.Count;
foreach (var fieldMetadata in typeMetadata.Fields)
{
    var fieldName = fieldMetadata.Name;
    var fieldType = fieldMetadata.Type;
}
typeMetadata.Fields.TryGetValue("FIELD_NAME", out var fieldNameMetadata);

Function Metadata

var functionMetadata = connection.GetFunctionMetadata("BAPI_SOME_FUNCTION_NAME");
var functionName = functionMetadata.GetName();
var parameterCount = functionMetadata.Parameters.Count;
foreach (var parameterMetadata in functionMetadata.Parameters)
{
    var parameterName = parameterMetadata.Name;
    var parameterType = parameterMetadata.Type;
}
functionMetadata.Parameters.TryGetValue("PARAMETER_NAME", out var parameterNameMetadata);

Ensure the SAP RFC SDK binaries are present

SapLibrary.EnsureLibraryPresent();

This will throw an SapLibraryNotFoundException with a meaningful message in case the SAP RFC SDK binaries were not found.

Connection String parameters

The SapConnection and SapConnectionPool class both take a SapConnectionParameters instance or a connection string in the form of:

"AppServerHost=MY_SERVER_HOST; SystemNumber=00; User=MY_SAP_USER; Password=SECRET; Client=100; Language=EN; PoolSize=5; Trace=3";

Click here to expand the list of supported connection parameters.

Field	SAP Field
AppServerHost	ASHOST
SncLibraryPath	SNC_LIB
SncQop	SNC_QOP
Trace	TRACE
SapRouter	SAPROUTER
NoCompression	NO_COMPRESSION
OnCharacterConversionError	ON_CCE
CharacterFaultIndicatorToken	CFIT
MaxPoolSize	MAX_POOL_SIZE
PoolSize	POOL_SIZE
SncPartnerNames	SNC_PARTNER_NAMES
IdleTimeout	IDLE_TIMEOUT
MaxPoolWaitTime	MAX_POOL_WAIT_TIME
RegistrationCount	REG_COUNT
PasswordChangeEnforced	PASSWORD_CHANGE_ENFORCED
Name	NAME
RepositoryDestination	REPOSITORY_DESTINATION
RepositoryUser	REPOSITORY_USER
RepositoryPassword	REPOSITORY_PASSWD
RepositorySncMyName	REPOSITORY_SNC_MYNAME
RepositoryX509Certificate	REPOSITORY_X509CERT
IdleCheckTime	IDLE_CHECK_TIME
SncMyName	SNC_MYNAME
SncPartnerName	SNC_PARTNERNAME
ProgramId	PROGRAM_ID
AppServerService	ASSERV
MessageServerHost	MSHOST
MessageServerService	MSSERV
R3Name	R3NAME
LogonGroup	GROUP
GatewayHost	GWHOST
GatewayService	GWSERV
SystemNumber	SYSNR
User	USER
AliasUser	ALIAS_USER
SncMode	SNC_MODE
Client	CLIENT
Password	PASSWD
Codepage	CODEPAGE
PartnerCharSize	PCS
SystemId	SYSID
SystemIds	SYS_IDS
X509Certificate	X509CERT
SapSso2Ticket	MYSAPSSO2
UseSapGui	USE_SAPGUI
AbapDebug	ABAP_DEBUG
LogonCheck	LCHECK
Language	LANG

Additional connection parameters can be added by creating a class that inherits from SapConnectionParameters:

public class MySapConnectionParameters : SapConnectionParameters
{
    [SapName("CST_PARAM")]
    public string CustomParameter { get; set; }
}

Input and output mapping

Input and output models used in function calls are mapped to and from SAP RFC parameter types by convention. In case the property name of the model differs from the SAP RFC parameter name, the [SapName]-attribute can be used.

For each input and output model type, the library builds and caches a mapping function using expression trees.

SAP RFC parameter types don't have to be specified as they're converted by convention. Here's an overview of supported type mappings:

C# type	SAP RFC type	Remarks
`int`	RFCTYPE_INT	4-byte integer
`long`	RFCTYPE_INT8	8-byte integer
`double`	RFCTYPE_FLOAT	Floating point, double precision
`decimal`	RFCTYPE_BCD
`string`	RFCTYPE_STRING / RFCTYPE_CHAR / ...	Gets a data field as string
`byte[]`	RFCTYPE_BYTE	Raw binary data, fixed length. Has to be used in conjunction with the `[SapBufferLength]`-attribute
`char[]`	RFCTYPE_CHAR	Char data, fixed length. Has to be used in conjunction with the `[SapBufferLength]`-attribute
`DateTime?`	RFCTYPE_DATE	Only the day, month and year value is used
`TimeSpan?`	RFCTYPE_TIME	Only the hour, minute and second value is used
`T`	RFCTYPE_STRUCTURE	Structures are constructed from nested objects (T) in the input or output model (see example)
`Array<T>`	RFCTYPE_TABLE	Tables are constructed from arrays of nested objects (T) in the input or output model (see example)
`IEnumerable<T>`	RFCTYPE_TABLE	Tables returned as IEnumerable. Yields elements one-by-one for better memory management when handling large datasets

Connection pooling

The usage examples above are for simple applications that execute functions one-by-one on a single connection.

For more complex applications that require concurrency, connection pooling and retry on disconnect, it is advised to use the SapPooledConnection and SapConnectionPool from the Pooling namespace.

See the SapConnectionPool class for configuration options.

Connection pooling in ASP.NET Core application

Register pool and pooled connection

In the Startup.cs ConfigureServices method, add:

services.AddSingleton<ISapConnectionPool>(_ => new SapConnectionPool(connectionString));
services.AddScoped<ISapPooledConnection, SapPooledConnection>();

Resolve a connection from the pool

In an ApiController or service, do:

[ApiController]
public class UserController : ControllerBase
{
    public UserController(ISapPooledConnection connection)
    {
        _connection = connection;
    }

    [HttpPost]
    public IActionResult DoSomething(string action)
    {
        _connection.InvokeFunction("BAPI_SOME_FUNCTION_NAME");
        return Ok();
    } 
}

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