int numPerPage = 20;
try {
docid = Integer.parseInt(args[1]);
} catch (Exception e) {
out.println("invalid docid, all docs are shown");
docid = -1;
int numPerPage = 20;
try {
String[] docListStrings = args[1].split(",");
for (String s : docListStrings) {
docidList.add(Integer.parseInt(s));
}