convert std::string to jstring encoded using windows-1256

I am using a library (libcurl) that requests a certain webpage with some Arabic content. when I obtain the string response it has Arabic characters and the whole response is encoded in WINDOWS-1256.

the problem is arabic chars dont show up properly.

is there a way to convert an std::string to a jstring encoded in WINDOWS-1256?

by the way I tried env->NewStringUTF(str.c_str()); and the application crashed.