I am using GeoRaptor 3.0.1.0012 for export of SDO_GEOMETRY with attributes encoded in UTF-8.
During export characters are lost. There should be option to select character encoding before writing data to .dbf
I have attached .shp file with ITF-8 encoded characters. Those characters can be properly imported and exported from Oracle Locator DB with other tools.
OpenJUUMP is making nice UTF-8 shapefile export if during startup option -Dfile.encoding="UTF-8"