protected void load() throws IOException, JSONException{
File vocabsFile = new File(workingDir,SAVED_VOCABULARIES_FILE_NAME);
FileReader reader = new FileReader(vocabsFile);
try {
JSONTokener tokener = new JSONTokener(reader);
JSONObject obj = (JSONObject) tokener.nextValue();
JSONArray prefixes = obj.getJSONArray("prefixes");
for(int i=0;i<prefixes.length();i++){
JSONObject p = prefixes.getJSONObject(i);
String name = p.getString("name");
String uri = p.getString("uri");