How to remove the last string from a stringbuilder?

Question

I'm dynamically creating a string

StringBuilder preparedStatement = new StringBuilder();
states.keySet().forEach(key -> preparedStatement
               .append(key)
               .append(" = ")
               .append(":")
               .append(key)
               .append(" AND "));

I want to remove the last AND at the end of the loop. Is this possible?

Answer 1

Yes. You know how wide the " AND " is, so just use StringBuilder#delete:

preparedStatement.delete(preparedStatement.length() - " AND ".length(),
                         preparedStatement.length()
                        );

Or, if you're about to turn it into a String anyway, use StringBuilder#substring:

String result = preparedStatement.substring(0,
                                            preparedStatement.length()
                                                - " AND ".length()
                                           );