java - 在android中通过jni调用c中的Main

Question

我想调用main:

int main(int argc, char *argv[])

我试过这个链接:How to use JNI to call a "main" function that takes an array of character pointers?

JNIEXPORT jint JNICALL Java_package_Class_lameMain(JNIEnv *env, jclass class,  jobjectArray jargv)
{    //jargv is a Java array of Java strings
     int argc = env->GetArrayLength(jargv);
     typedef char *pchar;
     pchar *argv = new pchar[argc];
     int i;
     for(i=0; i<argc; i++)
     {
         jstring js = env->GetObjectArrayElement(jargv, i); //A Java string
         const char *pjc = env->GetStringUTFChars(js); //A pointer to a Java-managed char buffer
         size_t jslen = strlen(pjc);
         argv[i] = new char[jslen+1]; //Extra char for the terminating null
         strcpy(argv[i], pjc); //Copy to *our* buffer. We could omit that, but IMHO this is cleaner. Also, const correctness.
         env->ReleaseStringUTFChars(js, pjc);
     }

     //Call main
     main(argc, argv);

    //Now free the array
    for(i=0;i<argc;i++)
       delete [] argv[i];
   delete [] argv;   
 }   

但它不起作用，因为我在 C 而不是 C++ 上编程。在我做了一些更改后，“GetArrayLength”出现了这个错误:

error: request for member 'GetArrayLength' in something not a structure or union

我也试过这个链接:How to call the main function in C file by JNI in Android?

 JNIEXPORT return_type JNICALL Java_full_package_name_classname_functionname(JNIEnv *env, jobject object, Jobject stringArray){
// your argc
int size = env->GetArrayLength(stringArray);
char **argv = new char*[size];
for (int i=0; i < size; ++i) 
{
    jstring string = env->GetObjectArrayElement(stringArrays, i);
    const char* cString = env->GetStringUTFChars(string, 0);
    argv[i] = strdup(cString);
    env->ReleaseStringUTFChars(string, myarray);
    env->DeleteLocalRef(string);
}
// you will need to modify main so it does properly cleanup
main(argc, argv);
// clean up
for(int i = 0; i < size; ++i)
    free(argv[i]);
delete [] argv;
}

错误是:预期的“；”或 ',' befor Java_package_Class_lameMain

Answer 1

像这样对你的函数进行 repdect 操作:

JNIEXPORT void JNICALL Java_ClassName_MethodName
  (JNIEnv *env, jobject obj, jstring javaString)
{

    const char *nativeString = (*env)->GetStringUTFChars(env, javaString, 0);

    (*env)->ReleaseStringUTFChars(env, javaString, nativeString);
}

事情是使用*env

请参阅此处的 C 示例 http://en.wikipedia.org/wiki/Java_Native_Interface