Jaa

RPC error 1702 when calling a WinAPI method from a batch job

  • Artikkeli

You probably already noticed that error messages are sometimes not really helpful when you are trying to understand a problem. The following code creates such misleading error message:

    1:  public void run()

    2:  {

    3:  ;

    4:  if(WinApi::folderExists(@"c:\temp\"))

    5:      info("Folder exists");

    6:  else

    7:      info("Folder does not exists");

    8:  }

If you do execute this code in a batch job, it will produce the following error message:

RPC error: RPC exception 1702 occurred in session xxx

1702 means:

The binding handle is invalid.

A complete list of RPC errors is available here.

But this error message has, of course, nothing to do with the real cause of the problem. The RPC 1702 is unfortunately in Ax 2009 (RTM and SP1) always thrown when you call a client method from a batch job. If you have a look at the code of the WinApi::folderExists(str filename):

    1:  client static boolean folderExists(Filename _filename)

    2:  {

    3:      boolean ret;

    4:      ;

    5:      ret = System.IO.Directory::Exists(_filename);

    6:      return ret;

    7:  }

you see that this method can’t be executed on the AOS because of the “client” keyword. It’s true that this should not work and create an error message (since batch jobs are executed on the AOS), but it should normally be a meaningful message.

Instead of calling this client method, you should change your code, so that this call can be executed on the server. For example like this:

    1:  public void run()

    2:  {

    3:      InteropPermission   interopPerm;

    4:      boolean isFolderExist;

    5:      ;

    6:   

    7:      interopPerm = new InteropPermission(InteropKind::ClrInterop);

    8:      interopPerm.assert();

    9:      isFolderExist = System.IO.Directory::Exists(@"c:\temp\");

   10:      

   11:      if(isFolderExist)

   12:      {

   13:          info("Folder exists");

   14:      }

   15:      else

   16:      {

   17:          info("Folder does not exists");

   18:      }

   19:   

   20:      CodeAccessPermission::revertAssert();

   21:  }

  

 Update (17/07/2009):

 You can find a blog entry from Klaas about this subject here:

 https://www.artofcreation.be/2009/04/08/winapi-rpc-1702-and-findfirstfilew/

Comments

  • Anonymous
    January 30, 2009
    You probably already noticed that error messages are sometimes not really helpful when you are trying

  • Anonymous
    February 11, 2009
    Hi Florian, The error message is indeed misleading, but the problem is obvious when you know a static method can’t run in batch. Thanks for the explanation, I was struggling with that RPC error. There is also a WinApiServer class that contains a lot of the methods that winapi offers. Because all static methods in that class run on server, it works perfectly in batch. Some methods that WinApi offers are not found in WinApiServer, but you can extend WinApiServer by copying methods from WinApi and changing ‘client’ to ‘server’. You just have to make sure that you assert the correct permissions (FileIOPermissen, InteropPermission,…) after declaring variables and right before initialising them. Or you can write your own method using System.IO like you did. Thank you for helping out!

  • Anonymous
    March 18, 2009
    The comment has been removed

  • Anonymous
    November 22, 2009
    Hello there! I was tried connect web services. I put into .dll in AX Server's folder. Now, solve my problem. bye. Thank you for post guys.