java and oracle

hai i am doing a project in which i have stored some data (think as 50 records) in database. Now i want to retrive the data from the database(20 records at each time but should be different for each time)..........
please help me for this..............

View Answers

March 11, 2010 at 10:50 AM

Hi Friend,

We have used Mysql for this purpose. Try the following code:

<%@ page language="java" %>
<%@ page import="java.sql.*" %>
<%!
public int nullIntconvert(String str){
int num=0;
if(str==null) {
str="0";
}
else if((str.trim()).equals("null")) {
str="0";
}
else if(str.equals("")) {
str="0";
}
try{
num=Integer.parseInt(str);
}
catch(Exception e) { }
return num;
}
%>
<%
Connection conn = null;
Class.forName("com.mysql.jdbc.Driver").newInstance();
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root";, "root");
ResultSet rs1 = null;
ResultSet rs2 = null;
PreparedStatement ps1=null;
PreparedStatement ps2=null;

int showRows=20;
int totalRecords=20;
int totalRows=nullIntconvert(request.getParameter("totalRows"));
int totalPages=nullIntconvert(request.getParameter("totalPages"));
int iPageNo=nullIntconvert(request.getParameter("iPageNo"));
int cPageNo=nullIntconvert(request.getParameter("cPageNo"));

int startResult=0;
int endResult=0;
if(iPageNo==0) {
iPageNo=0;
}
else{
iPageNo=Math.abs((iPageNo-1)*showRows);
}
String query1="SELECT SQL_CALC_FOUND_ROWS * FROM student limit "+iPageNo+","+showRows+"";
ps1=conn.prepareStatement(query1);
rs1=ps1.executeQuery();

String query2="SELECT FOUND_ROWS() as cnt";
ps2=conn.prepareStatement(query2);
rs2=ps2.executeQuery();
if(rs2.next()) {
totalRows=rs2.getInt("cnt");
}
%>
<html>
<h3>Pagination of JSP page</h3>
<body>
<form>
<input type="hidden" name="iPageNo" value="<%=iPageNo%>">
<input type="hidden" name="cPageNo" value="<%=cPageNo%>">
<input type="hidden" name="showRows" value="<%=showRows%>">
<table width="100%" cellpadding="0" cellspacing="0" border="1" >
<tr>
<td>Roll No</td>
<td>Name</td>
<td>Marks</td>
<td>Grade</td>
</tr>
<%
while(rs1.next()){
%>
<tr>
<td><%=rs1.getInt("rollNo")%></td>
<td><%=rs1.getString("name")%></td>
<td><%=rs1.getInt("marks")%></td>
<td><%=rs1.getString("grade")%></td>
</tr>
<%
}
%>
<%
try{
if(totalRows<(iPageNo+showRows)) {
endResult=totalRows;
}
else{
endResult=(iPageNo+showRows);
}
startResult=(iPageNo+1);
totalPages=((int)(Math.ceil((double)totalRows/showRows)));
}
catch(Exception e){
e.printStackTrace();
}
%>
<tr>
<td colspan="3">
<div>

March 11, 2010 at 10:51 AM

continue....

<%
int i=0;
int cPage=0;
if(totalRows!=0) {
cPage=((int)(Math.ceil((double)endResult/(totalRecords*showRows))));

int prePageNo=(cPage*totalRecords)-((totalRecords-1)+totalRecords);
if((cPage*totalRecords)-(totalRecords)>0){
%>
<a href="pagination.jsp?iPageNo=<%=prePageNo%>&cPageNo=<%=prePageNo%>"> << Previous</a>
<%
}
for(i=((cPage*totalRecords)-(totalRecords-1));i<=(cPage*totalRecords);i++){
if(i==((iPageNo/showRows)+1)){%>
<a href="pagination.jsp?iPageNo=<%=i%>" style="cursor:pointer;color: red"><b><%=i%></b></a>
<%
}
else if(i<=totalPages){
%>
<a href="pagination.jsp?iPageNo=<%=i%>"><%=i%></a>
<%
}
}
if(totalPages>totalRecords && i<totalPages){
%>
<a href="pagination.jsp?iPageNo=<%=i%>&cPageNo=<%=i%>"> >> Next</a>
<%
}
}
%>
<b>Rows <%=startResult%> - <%=endResult%> Total Rows <%=totalRows%> </b>
</div>
</td>
</tr>
</table>
</form>
</body>
</html>
<%
try{
if(ps1!=null){
ps1.close();
}
if(rs1!=null){
rs1.close();
}

if(ps2!=null){
ps2.close();
}
if(rs2!=null){
rs2.close();
}

if(conn!=null){
conn.close();
}
}
catch(Exception e)
{
e.printStackTrace();
}
%>

Hope that it will be helpful for you.
Thanks