As I said in my comment, I generally use nonstatic parser. The following "Answer" is more a guess than an authoritative answer. If you try it, please comment, so others (and I) can know whether it's right.
static SQLwhereS parser = null ;
public static void myParser(String toanalyze) throws ParseException
{
InputStream is = new ByteArrayInputStream( toanalyze.getBytes() );
if( parser==null) parser = new SQLwhereS(is); else ReInit(is) ;
.....
SQLwhereS.one_line();
.....
}