public interface CharacterConverter<T> {
    T convert(char c);
}
    
public class IntegerCharacterConverter implements CharacterConverter<Integer> {
    public Integer convert( char c ) {
        return ( int ) c; //autoboxing FTW
    }
}
    
char c = 't';
CharacterConverter<Integer> converter = new IntegerCharacterConverter();
int i = converter.convert( c ); //autounboxing FTW

int i = (int) c;