jvm.cpp

用 Java 代码处理本地对象的事件源代码 设有两部分

//////////////////////////////////////////////////////////////////////
// implementation of the CJvm class.

#include <windows.h>
#include "Jvm.h"

//////////////////////////////////////////////////////////////////////
// Construction/Destruction

JavaVM * CJvm::ms_jvm = NULL;
unsigned long CJvm::ms_tlsIndex = -1;

void CJvm::CreateJVM(int argc, char* argv[])
{
	if (-1 == ms_tlsIndex)
	{
		ms_tlsIndex = TlsAlloc();

		if (-1 == ms_tlsIndex)
		{
			return;
		}
	}

	JavaVMOption options[3];

	options[0].optionString = "-Djava.compiler=";

	for (int i = 0; i < argc; i++)
	{
		options[i+1].optionString = argv[i];
	}

	JavaVMInitArgs vm_args;
	vm_args.version = JNI_VERSION_1_4;
	vm_args.options = options;
	vm_args.nOptions = argc + 1;
	vm_args.ignoreUnrecognized = JNI_FALSE;

	void * pEnv = NULL;

	JNI_CreateJavaVM(&ms_jvm, &pEnv, &vm_args);

	TlsSetValue(ms_tlsIndex, pEnv);
}

void CJvm::DestroyJVM()
{
	if (NULL != ms_jvm)
	{
		ms_jvm->DestroyJavaVM();
		ms_jvm = NULL;
		ms_tlsIndex = -1;
	}
}

JavaVM * CJvm::GetJVM()
{
	return ms_jvm;
}

JNIEnv * CJvm::GetJNIEnv()
{
	if ((NULL == ms_jvm) || (-1 == ms_tlsIndex))
	{
		return NULL;
	}

	JNIEnv * env = (JNIEnv *) TlsGetValue(ms_tlsIndex);

	if (NULL != env)
	{
		return env;
	}

	ms_jvm->AttachCurrentThread((void **)&env, NULL);

	if (NULL == env)
	{
		return NULL;
	}

	TlsSetValue(ms_tlsIndex, env);

	return env;
}

jobject CJvm::CreateJavaObject(const char * szClassName, int handleSource)
{
	JNIEnv * env = GetJNIEnv();

	if (NULL == env)
	{
		return NULL;
	}

	jclass javaClass = env->FindClass(szClassName);

	if (NULL == javaClass)
	{
		return NULL;
	}

	jmethodID mid = env->GetMethodID(javaClass, "<init>", "(I)V");

	if (NULL == mid)
	{
		return NULL;
	}

	jobject jobj = env->NewObject(javaClass, mid, (jint)handleSource);

	return jobj;
}

void CJvm::ReleaseJObject(jobject jobj)
{
	JNIEnv * env = GetJNIEnv();

	if (NULL == env)
	{
		return;
	}

	jclass javaClass = env->GetObjectClass(jobj);

	if (NULL == javaClass)
	{
		return;
	}

	jmethodID mid = env->GetMethodID(javaClass, "release", "()V");

	if (NULL == mid)
	{
		return;
	}

	env->CallVoidMethod(jobj, mid);
}

void CJvm::DetachThread()
{
	if ((NULL == ms_jvm) || (-1 == ms_tlsIndex))
	{
		return;
	}

	JNIEnv * env = (JNIEnv *) TlsGetValue(ms_tlsIndex);

	if (NULL == env)
	{
		return;
	}

	TlsSetValue(ms_tlsIndex, NULL);
	ms_jvm->DetachCurrentThread();
	return;
}