Accessing VB Code using JNI

Can access functions implemented in Visual Basic from a Java program using JNI?
I was thinking like, since there's no .h file concept in VB, we can't access VB code from Java. Correct me if i am wrong....
Thanks,
Vasu

As long as the VB app somehow exports its functions via the standard "C" interface (which is how all DLLs are exported), then you can call into it via JNI. I've successfully used JNI to call into a Delphi DLL, for example.
The hard part is that VB doesn't want to do this by default, and to be honest, I'm not enough of a VB expert to tell you how you could do this. You can check your success, however, by running the dumpbin.exe utility (comes with MSVC) on the compiled DLL and see if your method shows up in some form. Once you know that name and how the parameters look (by-ref or by-val), you should be in good shape.
I won't say it's an easy road to go, however--you may have more luck just hosting the VB code as an ActiveX control and connecting to it via the higher-level Java->COM APIs. Stu Halloway has a collection of such links on his home page: http://staff.develop.com/halloway.

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    bstrt bstrLastErrorMessage = bstrt();
    bstrt bstrLastErrorNumber = bstrt();
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    jlong jEstablishedDueDay = NULL;
    jlong jLastPaymentAmount = NULL;
    jstring jLastPaymentDate = NULL;
    jstring jLastErrorMessage = NULL;
    jstring jLastErrorNumber = NULL;
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    const char *chLastErrorMessage = NULL;
    const char *chLastErrorNumber = NULL;
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    nativeIniFileName = env->GetStringUTFChars(iniFileName, &isCopy);
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    Edited by: Cthulhu76 on Jan 5, 2010 9:18 AM

    0x49202400 JavaThread "ContainerBackgroundProcessor[StandardEngine[Catalina]]" daemon [_thread_blocked, id=5340, stack(0x49bf0000,0x49c40000)]
    0x48a7e800 JavaThread "Thread-1" [_thread_in_native, id=5976, stack(0x48f00000,0x48f50000)]
    0x48a0dc00 JavaThread "Low Memory Detector" daemon [_thread_blocked, id=3072, stack(0x48c60000,0x48cb0000)]
    0x48a09000 JavaThread "CompilerThread0" daemon [_thread_blocked, id=4988, stack(0x48c10000,0x48c60000)]
    0x48a07c00 JavaThread "Attach Listener" daemon [_thread_blocked, id=3124, stack(0x48bc0000,0x48c10000)]
    0x48a07000 JavaThread "Signal Dispatcher" daemon [_thread_blocked, id=2572, stack(0x48b70000,0x48bc0000)]
    0x489f5c00 JavaThread "Finalizer" daemon [_thread_blocked, id=5752, stack(0x48b20000,0x48b70000)]
    0x489f4c00 JavaThread "Reference Handler" daemon [_thread_blocked, id=2596, stack(0x48ad0000,0x48b20000)]
    0x003c6000 JavaThread "main" [_thread_in_native, id=4252, stack(0x00820000,0x00870000)]
    Other Threads:
    0x489f0400 VMThread [stack: 0x48a80000,0x48ad0000] [id=5624]
    0x48a18800 WatcherThread [stack: 0x48cb0000,0x48d00000] [id=1192]
    VM state:not at safepoint (normal execution)
    VM Mutex/Monitor currently owned by a thread: None
    Heap
    def new generation total 36288K, used 12762K [0x02940000, 0x050a0000, 0x07800000)
    eden space 32256K, 34% used [0x02940000, 0x0343af58, 0x048c0000)
    from space 4032K, 37% used [0x04cb0000, 0x04e2ba28, 0x050a0000)
    to space 4032K, 0% used [0x048c0000, 0x048c0000, 0x04cb0000)
    tenured generation total 483968K, used 7518K [0x07800000, 0x250a0000, 0x42940000)
    the space 483968K, 1% used [0x07800000, 0x07f57958, 0x07f57a00, 0x250a0000)
    compacting perm gen total 14080K, used 14016K [0x42940000, 0x43700000, 0x46940000)
    the space 14080K, 99% used [0x42940000, 0x436f0320, 0x436f0400, 0x43700000)
    No shared spaces configured.
    Dynamic libraries:
    0x00400000 - 0x0040f000      C:\Program Files\Apache Software Foundation\Tomcat 5.5\bin\tomcat5.exe
    0x7c800000 - 0x7c8c0000      C:\WINDOWS\system32\ntdll.dll
    0x77e40000 - 0x77f42000      C:\WINDOWS\system32\kernel32.dll
    0x77380000 - 0x77411000      C:\WINDOWS\system32\USER32.dll
    0x77c00000 - 0x77c48000      C:\WINDOWS\system32\GDI32.dll
    0x77f50000 - 0x77feb000      C:\WINDOWS\system32\ADVAPI32.dll
    0x77c50000 - 0x77cef000      C:\WINDOWS\system32\RPCRT4.dll
    0x76f50000 - 0x76f63000      C:\WINDOWS\system32\Secur32.dll
    0x77ba0000 - 0x77bfa000      C:\WINDOWS\system32\MSVCRT.dll
    0x7c8d0000 - 0x7d0cf000      C:\WINDOWS\system32\SHELL32.dll
    0x77da0000 - 0x77df2000      C:\WINDOWS\system32\SHLWAPI.dll
    0x76290000 - 0x762ad000      C:\WINDOWS\system32\IMM32.DLL
    0x77420000 - 0x77523000      C:\WINDOWS\WinSxS\x86_Microsoft.Windows.Common-Controls_6595b64144ccf1df_6.0.3790.3959_x-ww_D8713E55\comctl32.dll
    0x6d7c0000 - 0x6da10000      C:\Program Files\Java\jre1.6.0_07\bin\client\jvm.dll
    0x76aa0000 - 0x76acd000      C:\WINDOWS\system32\WINMM.dll
    0x7c340000 - 0x7c396000      C:\WINDOWS\system32\MSVCR71.dll
    0x6d270000 - 0x6d278000      C:\Program Files\Java\jre1.6.0_07\bin\hpi.dll
    0x76b70000 - 0x76b7b000      C:\WINDOWS\system32\PSAPI.DLL
    0x6d770000 - 0x6d77c000      C:\Program Files\Java\jre1.6.0_07\bin\verify.dll
    0x6d310000 - 0x6d32f000      C:\Program Files\Java\jre1.6.0_07\bin\java.dll
    0x6d7b0000 - 0x6d7bf000      C:\Program Files\Java\jre1.6.0_07\bin\zip.dll
    0x6d570000 - 0x6d583000      C:\Program Files\Java\jre1.6.0_07\bin\net.dll
    0x71c00000 - 0x71c17000      C:\WINDOWS\system32\WS2_32.dll
    0x71bf0000 - 0x71bf8000      C:\WINDOWS\system32\WS2HELP.dll
    0x71b20000 - 0x71b61000      C:\WINDOWS\system32\mswsock.dll
    0x5f270000 - 0x5f2ca000      C:\WINDOWS\system32\hnetcfg.dll
    0x71ae0000 - 0x71ae8000      C:\WINDOWS\System32\wshtcpip.dll
    0x76ed0000 - 0x76efa000      C:\WINDOWS\system32\DNSAPI.dll
    0x76f70000 - 0x76f77000      C:\WINDOWS\System32\winrnr.dll
    0x76f10000 - 0x76f3e000      C:\WINDOWS\system32\WLDAP32.dll
    0x76f80000 - 0x76f85000      C:\WINDOWS\system32\rasadhlp.dll
    0x4a6a0000 - 0x4a6ac000      C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\MMI\WEB-INF\lib\CustomerInfoProxy.dll
    0x77670000 - 0x777a9000      C:\WINDOWS\system32\ole32.dll
    0x77d00000 - 0x77d8b000      C:\WINDOWS\system32\OLEAUT32.dll
    0x7c420000 - 0x7c4a7000      C:\WINDOWS\WinSxS\x86_Microsoft.VC80.CRT_1fc8b3b9a1e18e3b_8.0.50727.4053_x-ww_E6967989\MSVCP80.dll
    0x78130000 - 0x781cb000      C:\WINDOWS\WinSxS\x86_Microsoft.VC80.CRT_1fc8b3b9a1e18e3b_8.0.50727.4053_x-ww_E6967989\MSVCR80.dll
    0x777b0000 - 0x77833000      C:\WINDOWS\system32\CLBCatQ.DLL
    0x77010000 - 0x770d6000      C:\WINDOWS\system32\COMRes.dll
    0x77b90000 - 0x77b98000      C:\WINDOWS\system32\VERSION.dll
    0x75da0000 - 0x75e5d000      C:\WINDOWS\system32\SXS.DLL
    0x75e60000 - 0x75e87000      C:\WINDOWS\system32\apphelp.dll
    0x4dc30000 - 0x4dc5e000      C:\WINDOWS\system32\msctfime.ime
    0x4b0d0000 - 0x4b395000      C:\WINDOWS\system32\xpsp2res.dll
    0x71bb0000 - 0x71bb9000      C:\WINDOWS\system32\WSOCK32.dll
    0x4bbe0000 - 0x4bbea000      C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\MMI\WEB-INF\lib\ClearTranProxy.dll
    0x745e0000 - 0x7489e000      C:\WINDOWS\system32\msi.dll
    0x71c40000 - 0x71c97000      C:\WINDOWS\system32\NETAPI32.dll
    0x4bc50000 - 0x4bc6c000      C:\WINDOWS\system32\DBNETLIB.DLL
    0x71f60000 - 0x71f64000      C:\WINDOWS\system32\security.dll
    0x76c90000 - 0x76cb7000      C:\WINDOWS\system32\msv1_0.dll
    0x76cf0000 - 0x76d0a000      C:\WINDOWS\system32\iphlpapi.dll
    0x761b0000 - 0x76243000      C:\WINDOWS\system32\crypt32.dll
    0x76190000 - 0x761a2000      C:\WINDOWS\system32\MSASN1.dll
    0x4bcf0000 - 0x4bcff000      C:\Program Files\Common Files\System\Ole DB\SQLOLEDB.RLL
    0x4a8a0000 - 0x4a8aa000      C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\MMI\WEB-INF\lib\MIGI.DLL
    0x73570000 - 0x736c2000      C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\MMI\WEB-INF\lib\MSVBVM60.DLL
    0x4a950000 - 0x4a9e2000      C:\Program Files\Common Files\System\ado\msado15.dll
    0x74a50000 - 0x74a6a000      C:\WINDOWS\system32\MSDART.DLL
    0x4c850000 - 0x4c8c9000      C:\Program Files\Common Files\System\Ole DB\oledb32.dll
    0x4dbb0000 - 0x4dbc1000      C:\Program Files\Common Files\System\Ole DB\OLEDB32R.DLL
    VM Arguments:
    jvm_args: -Dcatalina.home=C:\Program Files\Apache Software Foundation\Tomcat 5.5 -Dcatalina.base=C:\Program Files\Apache Software Foundation\Tomcat 5.5 -Djava.endorsed.dirs=C:\Program Files\Apache Software Foundation\Tomcat 5.5\common\endorsed -Djava.io.tmpdir=C:\Program Files\Apache Software Foundation\Tomcat 5.5\temp -Djava.util.logging.manager=org.apache.juli.ClassLoaderLogManager -Djava.util.logging.config.file=C:\Program Files\Apache Software Foundation\Tomcat 5.5\conf\logging.properties -Djava.library.path=C:\Program Files\Apache Software Foundation\Tomcat 5.5\webapps\MMI\WEB-INF\lib vfprintf -Xms512m -Xmx1024m
    java_command: <unknown>
    Launcher Type: generic
    Environment Variables:
    JAVA_HOME=C:\Program Files\Java\jdk1.6.0_07
    [error occurred during error reporting (printing environment variables), id 0xc0000005]
    --------------- S Y S T E M ---------------
    OS: Windows Server 2003 family Build 3790 Service Pack 2
    CPU:total 4 (4 cores per cpu, 1 threads per core) family 6 model 7 stepping 6, cmov, cx8, fxsr, mmx, sse, sse2, sse3, ssse3
    Memory: 4k page, physical 2097151k(2097151k free), swap 4194303k(4194303k free)
    vm_info: Java HotSpot(TM) Client VM (10.0-b23) for windows-x86 JRE (1.6.0_07-b06), built on Jun 10 2008 01:14:11 by "java_re" with MS VC++ 7.1
    time: Mon Dec 28 15:24:00 2009
    elapsed time: 600 seconds

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