Re: FOLLOWUP: RE: [JAWIN] IStorage

I would probably fall under number 3!
But, do I really need those wrappers? As far as I understand, couldn't
I still use the same idea I used in my code to keep going?

updated code:

            //open Storage
            functionOpenStorage = new FuncPtr("ole32.dll", "StgOpenStorage");
            NakedByteStream nbs = new NakedByteStream();

            LittleEndianOutputStream leos = new LittleEndianOutputStream(nbs);

            leos.writeStringUnicode("Filename.QGD");
            leos.writeInt(0);
            leos.writeInt(0);
            leos.writeInt(0);
            leos.writeInt(0);
            int iIStoragePointer = 0;
            leos.writeInt(iIStoragePointer);

             functionOpenStorage.invoke("GIIIII::", 24, nbs, null,
ReturnFlags.CHECK_NONE);

             //Open Stream
             functionOpenStream = new FuncPtr("ole32.dll",
"OpenOrCreateStream");

But How do I use my iIStoragePointer to call the Open Stream Function.
In ole32, I found this method to open it: OpenOrCreateStream, but I
haven't found any documentation on it. Even if I find it, how do I use
the StoragePointer to call it?

I downloaded the files from the link:
http://www.codeproject.com/atl/structuredstorage.asp. There, there's a
method:
OpenStream(
        IStream** ppIStr,
        LPCOLESTR osName,
        DWORD mode)

My problem still remains, how do I use the iIStoragePointer to call it? If I do:

             //Open Stream
             functionOpenStream = new FuncPtr("ole32.dll", "OpenStream");
             NakedByteStream nbs2 = new NakedByteStream();
             LittleEndianOutputStream leos2 = new
LittleEndianOutputStream(nbs2);

             int iIStreamPointer = 0;
             leos2.writeInt(iIStreamPointer);
             leos2.writeStringUnicode("File Property");
             leos2.writeInt(0);

             //How can I invoke it without IStoragePointer?
             functionOpenStorage.invoke("IGI::", 12, nbs2, null,
ReturnFlags.CHECK_NONE);


Andre

On 6/5/06, Mcnamara, Sean D <[email protected]> wrote:
> Andre,
>
> A pointer to a pointer IStorage** is just an int. On a 32-bit platform,
> a 4-byte (4*8=32 bit) memory address represents the location of each
> space in memory. If you plan on calling this DLL in Windows 64-bit then
> use a Java long data type, or just use a long anyway to be safe (should
> work on 32-bit also.) When using pointers to and from a Windows DLL, the
> integer representing the pointer *is* your "object reference". The
> IStorage** pointer can eventually be used to call member functions of
> the IStorage object it points to. To get the whole picture *easily*, you
> need to use C++.
>
> If you want to avoid C++, the following COM wrapper around the
> Structured Storage API may be helpful:
>
> http://www.codeproject.com/atl/structuredstorage.asp
>
> This COM wrapper will be *much* easier to use from Jawin.
>
> Before you deploy this, however, be aware of the additional overhead
> incurred with your application:
> *You will have one more file (a .DLL) to keep with your application, in
> the bin directory with your .jar file.
> *With this class, your control over the structured storage will be
> somewhat less precise.
> *If you deploy into restricted environments such as a CITRIX server, you
> may not be able to use RegSvr32 (the api DllRegisterServer) to register
> this COM library. Failure to register a COM DLL is almost always bad
> news for any application hoping to call the library.
>
> At this intersection, you have several choices to proceed:
>
> 1. If you can't use COM in your environment and you have a Visual C++
> compiler, use it! Write your code in C++ first and, once you get a
> working C++ test case, the Jawin usage will become much clearer to you.
>
> 2. If you can use COM in your environment and you have a Visual C++
> compiler, compile the source code linked to above, into a Windows DLL.
> Then use Jawin Type Browser to generate Java wrappers.
>
> 3. If you can use COM in your environment and you don't have a Visual
> C++ compiler, let me know and I will try and compile the sample DLL and
> email it to you. It uses ATL so I'll see about static linking, and will
> try and provide two versions (one with debugging symbols, and one
> without) for convenience.
>
> 4. If you can't use COM in your environment and you don't have a Visual
> C++ compiler, you're doing pretty badly, here! :-) In this case you
> should probably look into alternative libraries, or buying a Visual C++
> compiler so you can learn how to interact with these APIs.
>
> Good luck,
> Sean
>
>
>
> -----Original Message-----
> From: Discussion of Java/Win32/COM integration with Jawin
> [mailto:[email protected]] On Behalf Of Andre R. Santos
> Sent: Monday, June 05, 2006 2:37 PM
> To: [email protected]
> Subject: Re: [JAWIN] FOLLOWUP: RE: [JAWIN] IStorage
>
> I'm using the techniques described at
> http://jawinproject.sourceforge.net/jawin.html#callingDll and I'm
> getting an
> error. This is what I've done so far:
>
> Using Depency Walker, I found out that the function I want to call is
> StgOpenStorage. This is the method signature:
>
> WINOLEAPI StgOpenStorage(
>   const WCHAR* pwcsName,
>   IStorage* pstgPriority,
>   DWORD grfMode,
>   SNB snbExclude,
>   DWORD reserved,
>   IStorage** ppstgOpen
> );
>
> "IStorage** ppstg: [out] When the operation is successful, pointer to
> the
> location of an IStorage pointer to the opened storage object. This
> parameter
> is set to NULL if an error occurs."
>
> What should I pass as a ppstgOpen parameter, and how I can use it later
> to
> open an IStream Object?
>
> Here's the code, which works fine, I just don't know what do to next:
>
>             functionOpenStorage= new FuncPtr("ole32.dll",
> "StgOpenStorage");
>             NakedByteStream nbs = new NakedByteStream();
>             LittleEndianOutputStream leos = new
> LittleEndianOutputStream(nbs);
>
>             leos.writeStringUnicode("D:\\Filename.QGD");
>             leos.writeInt(0);
>             leos.writeInt(0);
>             leos.writeInt(0);
>             leos.writeInt(0);
>
> //what parameter should I pass here? (using 0 to test)
>             leos.writeInt(0);
>
>              functionOpenStorage.invoke("GIIIII::", 24, nbs, null,
> ReturnFlags.CHECK_NONE);
>