servlet code

how to implement paging or pagination in java code using servlets.

View Answers

March 23, 2010 at 5:37 PM

Hi Friend,

Try the following code:

import java.io.*;
import java.sql.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class PaginationInServlet extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws IOException, ServletException{
PrintWriter out = response.getWriter();
Connection conn = null;
try{
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=5;
int totalRecords=5;
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");
System.out.println(totalRows);
}
out.println("<html><h3>Pagination of JSP page</h3><body><form>");
out.println("<input type='hidden' name='iPageNo' value='<%=iPageNo%>'>");
out.println("<input type='hidden' name='cPageNo' value='<%=cPageNo%>'>");
out.println("<input type='hidden' name='showRows' value='<%=showRows%>'>");
out.println("<table width='100%' cellpadding='0' cellspacing='0' border='1' >");
out.println("<tr><td>Roll No</td><td>Name</td><td>Marks</td><td>Grade</td></tr>");
while(rs1.next()){
out.println("<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();
}
out.println("<tr><td colspan='3'><div>");
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){
out.println("<a href=PaginationInServlet?iPageNo="+prePageNo+"&cPageNo="+prePageNo+"'> << Previous</a>");
}
for(i=((cPage*totalRecords)-(totalRecords-1));i<=(cPage*totalRecords);i++){
if(i==((iPageNo/showRows)+1)){
out.println("<a href=PaginationInServlet?iPageNo="+i+"style=cursor:pointer;color: red><b>"+i+"</b></a>");
}
else if(i<=totalPages){
out.println("<a href=PaginationInServlet?iPageNo="+i+">"+i+"</a>");
}
}
if(totalPages>totalRecords && i<totalPages){
out.println("<a href=PaginationInServlet?iPageNo="+i+"&cPageNo="+i+"> >> Next</a>");
}
}
out.println("<b>Rows "+startResult+"-"+endResult+"Total Rows"+totalRows+"</b></div></td></tr></table></form></body></html>");

March 23, 2010 at 5:38 PM

continue..

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();
}
}
catch(Exception ex){}
}
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;
}
}

For the above code, we have used following database table:

CREATE TABLE `student` (
`rollNo` bigint(40) NOT NULL auto_increment,
`name` varchar(40) default NULL,
`marks` varchar(40) default NULL,
`grade` varchar(40) default NULL,
PRIMARY KEY (`rollNo`)
)

Thanks