jni converting jstring to char *

JNIEXPORT void JNICALL Java_ClassName_MethodName(JNIEnv *env, jobject obj, jstring javaString)  
{
   const char *nativeString = (*env)->GetStringUTFChars(env, javaString, 0);

   // use your string

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