Java HotSpot Virtual Machine

can we dynamically link jvm.dll using command line (cl) option?

or how can we directly embed the jvm.dll path in the code?
a simple code will be helpful

jvm.dll is in the path: c:\program files\java\jdk1.5.0_06\jre\bin\client

thanks again

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voil�

You mean statically link, right? And it's with link.exe and not cl.exe.
But you can also dynamically load jvm.dll at runtime of course.
Yes you could load dynamically jvm.dll with its absolute path but it would not be very useful on machines other than yours, right?

To be able to use the JNI invocation API, you need to "find" statically or dynamically the JNI_CreateJavaVM function.

** Statically **:

To build:

// C code (very simple example without error checking):

JavaVM * jvm = NULL;

jint create_jvm()
{
    JavaVMInitArgs vm_args;
    JavaVMOption options[1];
    JNIEnv * env;
    
    options[0].optionString = "-Djava.class.path=.";
    
    vm_args.options = options;
    vm_args.nOptions = 1;
    vm_args.version = JNI_VERSION_1_4;
    vm_args.ignoreUnrecognized = JNI_FALSE;
    
    return JNI_CreateJavaVM(&jvm, (void **)&env, &vm_args);
}

// Compiler settings to your Visual Studio project:
Configuration properties|C/C++|General|Additional Include Directories: {jdk_root_folder}\include\win32;{jdk_root_folder}\include
// Linker settings to your Visual Studio project:
Configuration properties|Linker|Input|Additional Dependencies: jvm.lib ( located in {jdk_root_folder}\lib )

To run:

Add to the Path environment variable the jvm.dll location
Path=C:\Program Files\Java\jre1.5.0_06\bin\client;%Path%


** Dynamically **:

To build:

// C code (very simple example without error checking):

typedef jint (*type_JNI_CreateJavaVM)(JavaVM ** pJvm, JNIEnv ** pEnv, void * vmArgs);

HINSTANCE hLib = NULL;
JavaVM * jvm = NULL;

jint create_jvm()
{
    type_JNI_CreateJavaVM fct_JNI_CreateJavaVM;
    JavaVMInitArgs vm_args;
    JavaVMOption options[1];
    JNIEnv * env;
    
    hLib = LoadLibrary("jvm.dll");
    fct_JNI_CreateJavaVM = (type_JNI_CreateJavaVM)GetProcAddress(hLib, "JNI_CreateJavaVM");
    
    options[0].optionString = "-Djava.class.path=.";
    
    vm_args.options = options;
    vm_args.nOptions = 1;
    vm_args.version = JNI_VERSION_1_4;
    vm_args.ignoreUnrecognized = JNI_FALSE;
    
    return (*fct_JNI_CreateJavaVM)(&jvm, &env, &vm_args);
}

// Compiler settings to your Visual Studio project:
Configuration properties|C/C++|General|Additional Include Directories: {jdk_root_folder}\include\win32;{jdk_root_folder}\include

To run:

Add to the Path environment variable the jvm.dll location
Path=C:\Program Files\Java\jre1.5.0_06\bin\client;%Path%

Regards

thanks :)