008android初级篇之jni中数组的传递

public native boolean changeAccountPasswd(byte[] passwd,int len);

JNIEXPORT jboolean  JNICALL Java_com_frank_smart_smarthome_JniSocket_changeAccountPasswd
        (JNIEnv *env, jobject object,jbyteArray passwd,jint len)
{
   jbyte *bytes;
   unsigned char *buf;
   int i;

    //从jbytearray获取数据到jbyte*
   bytes = env->GetByteArrayElements(passwd,NULL);
   if(bytes == NULL) {
      return false;
   }
   buf =(unsigned char *)calloc(len,sizeof(char));
   if(buf == NULL)
   {
      return false;
   }
   for(i=0;i<len;i++)
   {
      *(buf+i)=(unsigned char)(*(bytes+i));
   }
    //释放资源
   env->ReleaseByteArrayElements(passwd,bytes,0);
   __android_log_write(ANDROID_LOG_ERROR,"TAG",(char*)buf);
   free(buf);
   return true;
}