VARSTRMARSHALER.C

//===================================================================== 
// Sample Java/COM Marshaling Hook Class. 
// 
// Java Type:  String 
// Com  Type:  VARIANT (BSTR type). 
//  
// Copyright (c) 1996-1997  Microsoft Corporation.  All rights reserved. 
//===================================================================== 
 
 
 
 
#pragma hdrstop 
 
#include <windows.h> 
#include "native.h" // Raw Native Interface declarations. 
 
 
 
typedef VARIANT *PVARIANT, **PPVARIANT; 
 
 
 
#ifdef __cplusplus 
#define EXTERNC     extern "C" 
#else 
#define EXTERNC 
#endif 
 
 
// Macro for declaring RNI Java methods's (and encapsulating the java class package.) 
#define JAVAMETHOD(typ, name) \ 
    __declspec(dllexport) \ 
    EXTERNC \ 
    typ __cdecl VarStrMarshaler_##name 
 
// Export that tells what RNI version we were built under. 
DWORD __cdecl RNIGetCompatibleVersion() 
{ 
  return RNIVER; 
} 
 
 
#define LOGCALL(hookname) OutputDebugString("VarStrMarshaler." hookname "() called.\n") 
 
 
//========================================================================== 
// toJava 
//========================================================================== 
JAVAMETHOD(HString*, toJava) (OBJECT*x, PPVARIANT ppVARIANT, int flags) 
{ 
    VARIANT *pvar = *ppVARIANT; 
 
    LOGCALL("toJava"); 
 
     
    if (pvar->vt != VT_BSTR) { 
        // Could try to coerce the variant, but this is just an example. 
        SignalErrorPrintf("java/lang/IllegalArgumentException", 
                          "Variant is of wrong type (must be VT_BSTR.)"); 
    } else { 
        return makeJavaStringW(pvar->bstrVal, SysStringLen(pvar->bstrVal)); 
    } 
} 
 
 
//========================================================================== 
// copyToExternal 
//========================================================================== 
JAVAMETHOD(void, copyToExternal) (OBJECT*x, HString* javaval, PPVARIANT ppVARIANT, int flags) 
{ 
    PVARIANT pVARIANT = *ppVARIANT; 
    BSTR bstr; 
 
    LOGCALL("copyToExternal"); 
 
    if (!javaval) { 
        SignalErrorPrintf("java/lang/NullPointerException", "Null string not allowed."); 
    } else { 
        bstr = SysAllocStringLen(javaStringStart(javaval), 
                                 (UINT)(javaStringLength(javaval))); 
     
     
        if (!bstr) { 
            SignalErrorPrintf("java/lang/OutOfMemoryError", "Not enough room in BSTR system heap."); 
        } else { 
     
            char msg[100]; 
            wsprintf(msg, "Hook class allocated BSTR at %lxh\n", bstr); 
            OutputDebugString(msg); 
     
            // We explicitly do NOT call VariantClear before overwriting the variant. 
            // That is the job of releaseByValExternal, which will be called when needed. 
            pVARIANT->vt      = VT_BSTR; 
            pVARIANT->bstrVal = bstr; 
        } 
    } 
 
} 
 
 
//========================================================================== 
// releaseByValExternal 
//========================================================================== 
JAVAMETHOD(void, releaseByValExternal) (OBJECT*x, PPVARIANT ppVARIANT, int flags) 
{ 
    PVARIANT pVARIANT = *ppVARIANT; 
 
    LOGCALL("releaseByValExternal"); 
    if (pVARIANT->vt == VT_BSTR) { 
        char msg[100]; 
        wsprintf(msg, "Hook class freeing BSTR at %lxh\n", pVARIANT->bstrVal); 
        OutputDebugString(msg); 
 
        SysFreeString(pVARIANT->bstrVal); 
    } 
} 
 
 
 
//========================================================================== 
// TODO: Remove this copy of DllMain if you are embedding this file in your 
//  own DLL. 
// DLL Loader entry point. 
//========================================================================== 
BOOL WINAPI DllMain(HINSTANCE hmod, DWORD dwReason, 
                                PVOID pvReserved) 
{ 
   return TRUE; 
}