jnidemo2.c

精通Java核心技术的随书源代码

#include <jni.h>
	
#ifdef _WIN32
#define PATH_SEPARATOR ';'
#else
#define PATH_SEPARATOR ':'
#endif
	
int main()
{
   JavaVMOption options[1];
   JNIEnv *env;
   JavaVM *jvm;
   JavaVMInitArgs vm_args;
   long status;
   jclass cls;
   jmethodID mid;
   jint square;
   jboolean not;
   options[0].optionString = "-Djava.class.path=.";
   memset(&vm_args, 0, sizeof(vm_args));
   vm_args.version = JNI_VERSION_1_4;
   vm_args.nOptions = 1;
   vm_args.options = options;
   status = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);

   if (status != JNI_ERR)
   {
      cls = (*env)->FindClass(env, "JNIDemo2");
      if(cls !=0)
      {
         mid = (*env)->GetStaticMethodID(env, cls, "intMethod", "(I)I");
         if(mid !=0)
         {
            square = (*env)->CallStaticIntMethod(env, cls, mid, 5);
			  printf("Result of intMethod: %d\n", square);
         }  
	
         mid = (*env)->GetStaticMethodID(env, cls, "booleanMethod", "(Z)Z");
         if(mid !=0)
  	     {
           not = (*env)->CallStaticBooleanMethod(env, cls, mid, 1);
           printf("Result of booleanMethod: %d\n", not);
         }
       }
	
       (*jvm)->DestroyJavaVM(jvm);
       return 0;
   }
   else
   return -1;
}