Pagination logic - dynamic Map inside Map - JSTL

From:
kiran <kiranmbadi@gmail.com>
Newsgroups:
comp.lang.java.help
Date:
Tue, 28 Aug 2012 17:22:22 -0700 (PDT)
Message-ID:
<aa4bb3ec-c177-459d-909e-6b3dbac04727@googlegroups.com>
Hi All,

I need to implement simple pagination displaying 100 records per page and p=
agination data is sorted by date with data as an header.Though I have sorte=
d the information correctly,however I am unable to think about pagination l=
ogic since resultset is inside map which is again holding dynamic Map insi=
de it and I am not able to restrict the dynamic map to the page size.
 
Map<Date, LinkedHashMap<Integer, String>> TitleList = new LinkedHashMap<D=
ate, LinkedHashMap<Integer, String>>();
 
LinkedHashMap<Integer, String> Title = new LinkedHashMap<Integer, String>=
();
 
<c:forEach items="${TitleList}" var="column">
            <p><c:out value="${column.key}"/></p> =
 
            <c:forEach var="Title" items="${column.value}">
                <p><a href="<%=request.getContextPath()%>/Test.do?id==
${Title.key}"><c:out value="${Title.value}"/></a></p>
            </c:forEach>
        </c:forEach>

Below is code through which I am generating the map,

Map<Date, LinkedHashMap<Integer, String>> TitleList = new LinkedHashMap<D=
ate, LinkedHashMap<Integer, String>>();
            String sqld = "Select Distinct DATE(timestamp) as DATE from t=
able ORDER BY DATE DESC LIMIT 730 ;";
            ResultSet rsd = null;
            try {
                rsd = stmt1.executeQuery(sqld);
            } catch (SQLException ex) {
                Logger.getLogger(myclass.class.getName()).log(Level.SEVERE,=
 null, ex);
            }
            try {
                while (rsd.next()) {
                    LinkedHashMap<Integer, String> Title = new LinkedHash=
Map<Integer, String>();
            // System.out.println("Testing");
                    Date Date = rsd.getDate("Date");
            // System.out.println(Date);
                    String sql = "Select title,id from table Where DATE(t=
imestamp) = '" + Date + "'ORDER BY id DESC";
           // System.out.println(sql);
                    ResultSet rs = stmt.executeQuery(sql);
                    rs.last();
                    int numRows = rs.getRow();
          // System.out.println(rs.getRow());
                    rs.beforeFirst();
                    while (rs.next()) { =
 
                        for (int i = 1; i <= numRows; i++) {
                            String title = rs.getString("title");
                            Integer id = rs.getInt("id");
                               Title.put(id, title); =
   
                            TitleList.put(Date, Title);
                        }
                        System.out.println("Size of LinkedHashMap for Title=
  : " + Title.size());
         // System.out.println(rs.getString("title"));
                    }
 
                }

Map structure looks like this

map = {2012-07-12={160=tstng, 159=testing}, 2012-07-10={158=tes=
t, 157=test, 156=Testing, 155=Testing, 154=Testing, 153=Testing, =
152=Testing, 151=Testing, 150=Testing, 149=Testing, 148=Testing, =
147=Testing, 146=Testing, 145=Testing, 144=Testing, 143=Testing, =
142=Testing, 141=Teasting, 140=Teasting, 139=Testing, 138=Testing=
, 137=Testing , 136=Testing for testing, 135=Testing for testing, 134=
=Testing for Test, 133=Testing}, 2012-07-04={132=Testing for Broker=
}, 2012-07-03={131=Testing for Post, 130=1200 TESTIN}, 2012-07-01={=
129=testing}, 2012-03-30={128=upload test}, 2012-03-28={127=test}=
, 2012-01-08={126=1BHK flat for 1000$ at Journal Square}, 2012-01-04==
{125=tseting by kiran, 124=tseting by kiran, 123=tseting by kiran, 12=
2=tseting by kiran, 121=tseting by kiran, 120=tseting by kiran, 119=
=tseting by kiran, 118=tseting by kiran, 117=tseting by kiran, 116==
tseting by kiran, 115=tseting by kiran, 114=tseting by kiran, 113=tse=
ting by kiran, 112=tseting by kiran, 111=tseting by kiran, 110=tsetin=
g by kiran, 109=tseting by kiran, 108=tseting by kiran, 107=tseting b=
y kiran, 106=tseting by kiran, 105=tseting by kiran, 104=tseting by k=
iran}, 2012-01-02={103=testing, 102=testing, 101=testing, 100=tes=
ting, 99=testing, 98=testing, 97=testing, 96=testing, 95=testing,=
 94=testing, 93=testing, 92=testing, 91=testing, 90=testing, 89=
=testing, 88=testing, 87=testing, 86=testing, 85=testing, 84=te=
sting, 83=testing, 82=testing, 81=testing, 80=testing, 79=testing=
, 78=testing, 77=testing, 76=testing, 75=testing, 74=testing}, 20=
11-12-09={73=The monthly consumer price index rose 4.2% from the year-a=
go period, reflecting a huge easing from October=E2??s 5.5% increase. }, 20=
11-12-08={72=Testing for dispplay}, 2011-11-25={71=Apartment for Re=
nt at Journal Square for 1000$.Please see now., 70=Apartment for Rent at =
Journal Square for 1000$.Please see now., 69=testing, 68=AS, 67=A, 66=
=A, 65=q, 64=q, 63=Testing, 62=Testing}, 2011-11-24={61=testi=
ng, 60=tEST, 59=TESTING, 58=TESTING, 57=Testing, 56=Testing, 55=
=Testing, 54=tseting, 53=testing, 52=testing, 51=testing, 50=te=
ting, 49=tESTING, 48=tESTING, 47=tESTING, 46=Testing, 45=TESTING,=
 44=TESTING, 43=tESTING}, 2011-11-23={42=Testing, 41=testing, 40=
=Testing, 39=tESTING, 38=TETING, 37=testing}, 2011-11-22={36=Te=
sting, 35=Testing, 34=Testing, 33=Testing by Kiran, 32=testing, 31=
=Testing, 30=Testing by Kiran, 29=Testing byt kiran, 28=Testing by =
Kiran, 27=testing by kiran, 26=testing by kiran, 25=Testing , 24=TS=
ETING, 23=Testing by Kiran}, 2011-11-21={22=testing, 21=Testng, 20=
=TESTING, 19=TESTING, 18=ESTING, 17=ESTING, 16=ESTING, 15=ESTIN=
G, 14=testing by kiran, 13=testing by Kiran, 12=Testing by Kiran, 11=
=testing by Kiran, 10=Testing by Kian, 9=Testing by Kiran, 8=Testin=
g by Kiran, 7=Testing byKiran, 6=testing, 5=Test by Kiran, 4=Test b=
y Kiran}, 2011-11-20={3=testing, 2=testing, 1=testing}}

I tried various ways to implement this with List/Maps with no success at al=
l.

Can someone point me is their correct way of doing pagination with Maps ?

I need something like

Date 1
Title 10
Title 09
Title 08
Date 2
Title07
Title06

Like wise till Title reaches 100 records and next should move to next page.

Appreciate if someone can help me on this.I have spend many sleepless night=
s trying to work this out,but I dont see anywhere where maps structure has =
been used for pagination.I know how to do this via Lists but Lists do not m=
eet my requirements.From Servlets I do get output what I require but in vie=
w I am not able to restrict records per page as 100 given dynamic nature of=
 inner map for each date.

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