String to JNI gets extra characters

I am calling JNI method from Java app with couple of Str开发者_如何学Cing arguments. I am using env->GetStringChars(arg1, 0 ); to get that strings. Problem is that I sometimes get some extra special characters or string is truncated.

In Java, chars are 16-bit characters (UTF-16 encoded). If you treat them as a plain char* in C you will see nul bytes (which is usually treaded as the end of the String) or other special characters.

Perhaps you should use the UTF encoding which avoid nul char. You will still need to handle special characters which are UTF encoded.

http://java.sun.com/docs/books/jni/html/objtypes.html

Finally I found a solution

const jchar* raw = env->GetStringChars(string, NULL);
if (raw == NULL)
    return NULL;

wchar_t* wsz = new wchar_t[len+1];
memcpy(wsz, raw, len*2);
wsz[len] = 0;

env->ReleaseStringChars(string, raw);

return wsz;