Okay so after trying some codes from the incomplete documentations and trying to pass the symbol id attribute using different key names i achieved what i was trying to do. goes like:
File stylxFile = new File(System.getProperty("user.dir") + "\\mil2525d.stylx");
DictionarySymbolStyle symbolDictionary = DictionarySymbolStyle.createFromFile(stylxFile.getAbsolutePath());
symbolDictionary.loadAsync();
Map<String, Object> attributes = new HashMap<>();
attributes.put("sidc", 10000000000000000000); // pass here a unique 20 digit Symbol ID Code
try {
Symbol s = symbolDictionary.getSymbolAsync(attributes).get();
} catch (InterruptedException e) {
e.printStackTrace();
System.out.println("InterruptedException - failed to symbolize SIDC: "+ sidc);
} catch (ExecutionException e) {
e.printStackTrace();
System.out.println("ExecutionException - failed to symbolize SIDC: "+ sidc);
}