A Practical JSP paging code

Some enthusiastic netizens replied:
STR + = "go to <select name = 'page' onchange = \" window. location. href = '"+ filename + temp +" cur_page =' + this. options [this. selectedindex]. value \ "> ";
I already tried it. No problem

1. The following is a pagination class pageresultset.

CopyCode The Code is as follows: Package page. Bean;
Import java. util .*;
Public class pageresultset {
/**
* Paging data
*/
Private collection data = NULL;
/**
* Current page
*/
Private int curpage;
/**
* Number of records displayed on each page
*/
Private int pagesize;
/**
* Number of records
*/
Private int rowscount;
/**
* Page number
*/
Private int pagecount;
Public pageresultset (collection data ){
This. Data = data;
This. curpage = 1;
This. pagesize = 10;
This. rowscount = data. Size ();
This. pagecount = (INT) math. Ceil (double) rowscount/pagesize );
}
Public pageresultset (collection data, int curpage ){
This. Data = data;
This. curpage = curpage;
This. pagesize = 10;
This. rowscount = data. Size ();
This. pagecount = (INT) math. Ceil (double) rowscount/pagesize );
}
Public pageresultset (collection data, int curpage, int pagesize ){
This. Data = data;
This. curpage = curpage;
This. pagesize = pagesize;
This. rowscount = data. Size ();
This. pagecount = (INT) math. Ceil (double) rowscount/pagesize );
}
/**
* Getcurpage: returns the current page number.
*
* @ Return int
*/
Public int getcurpage (){
Return curpage;
}
/**
* Getpagesize: returns the page size.
*
* @ Return int
*/
Public int getpagesize (){
Return pagesize;
}
/**
* Getrowscount: Total number of returned records
*
* @ Return int
*/
Public int getrowscount (){
Return rowscount;
}
/**
* Getpagecount: Total number of returned pages
*
* @ Return int
*/
Public int getpagecount (){
Return pagecount;
}
/**
* Page 1
*
* @ Return int
*/
Public int first (){
Return 1;
}
/**
* Last Page
*
* @ Return int
*/
Public int last (){
Return pagecount;
}
/**
* Previous Page
*
* @ Return int
*/
Public int previous (){
Return (curpage-1 <1 )? 1: curpage-1;
}
/**
* Next Page
*
* @ Return int
*/
Public int next (){
Return (curpage + 1> pagecount )? Pagecount: curpage + 1;
}
/**
* Page 1
*
* @ Return Boolean
*/
Public Boolean isfirst (){
Return (curpage = 1 )? True: false;
}
/**
* Last Page
*
* @ Return Boolean
*/
Public Boolean islast (){
Return (curpage = pagecount )? True: false;
}
/*** Get the current page data
*
* @ Return collection
*/
Public Collection getdata (){
Collection curdata = NULL;
If (Data! = NULL ){
Int start = (curpage-1) * pagesize;
Int end = 0;
If (start + pagesize> rowscount)
End = rowscount;
Else
End = start + pagesize;
Arraylist arraycurdata = new arraylist ();
Arraylist arraydata = NULL;
Vector vectorcurdata = new vector ();
Vector vectordata = NULL;
Boolean isarray = true;
If (Data instanceof arraylist ){
Arraydata = (arraylist) data;
Isarray = true;
} Else if (Data instanceof vector ){
Vectordata = (vector) data;
Isarray = false;
}
For (INT I = start; I <end; I ++ ){
If (isarray ){
Arraycurdata. Add (arraydata. Get (I ));
} Else {
Vectordata. Add (vectordata. elementat (I ));
}
}
If (isarray ){
Curdata = (Collection) arraycurdata;
} Else {
Curdata = (Collection) vectorcurdata;
}
}
Return curdata;
}
/**
* Get tool bar
*
* @ Return string
*/
Public String gettoolbar (string filename ){
String temp = "";
If (filename. indexof ("? ") =-1 ){
Temp = "? ";
} Else {
Temp = "&";
}
String STR = "<form method = 'post' name = 'frmpage' action = '" + filename + "'> ";
STR + = "<p align = 'center'> ";
If (isfirst ())
STR + = "homepage previous ";
Else {
STR + = "<a href = '" + filename + temp + "cur_page = 1'> homepage </a> ";
STR + = "<a href = '" + filename + temp + "cur_page =" + (curpage-1) + "'> previous page </a> ";
}
If (islast ())
STR + = "next last page ";
Else {
STR + = "<a href = '" + filename + temp + "cur_page =" + (curpage + 1) + "'> next page </a> ";
STR + = "<a href = '" + filename + temp + "cur_page =" + pagecount + "'> last page </a> ";
}
STR + = "Total <B>" + rowscount + "</B> records ";
STR + = "go to <select name = 'page' onchange =" location = '"+ filename
+ Temp + "cur_page = '+ this. Options [This. selectedindex]. Value"> ";
For (INT I = 1; I <= pagecount; I ++ ){
If (I = curpage)
STR + = "<option value = '" + I + "'selected> page" + I + "</option> ";
Else
STR + = "<option value = '" + I + "'> page" + I + "</option> ";
}
STR + = "</SELECT> </P> </form> ";
Return STR;
}
}

2. Here is action. Copy code The Code is as follows :/*
* Generated by myeclipse struts
* Template path: templates/Java/javaclass. VTL
*/
Package struts. Action;
Import java. util. collection;
Import javax. servlet. http. httpservletrequest;
Import javax. servlet. http. httpservletresponse;
Import org. Apache. Struts. action. Action;
Import org. Apache. Struts. Action. actionform;
Import org. Apache. Struts. Action. actionforward;
Import org. Apache. Struts. Action. actionmapping;
Import page. Bean. databaseconn;
Import page. Bean. pageresultset;
Import page. Bean. contactbo;
Import struts. Form. loginform;
/**
* Myeclipse struts
* Creation date: 04-02-2008
*
* XDoclet definition:
* @ Struts. Action Path = "/login" name = "loginform" input = "/login. jsp" Scope = "request" Validate = "true"
* @ Struts. Action-forward name = "Sss" Path = "/index. jsp"
*/
Public class loginaction extends action {
/*
* Generated Methods
*/
/**
* Method Execute
* @ Param Mapping
* @ Param form
* @ Param request
* @ Param response
* @ Return actionforward
*/
Public actionforward execute (actionmapping mapping, actionform form,
Httpservletrequest request, httpservletresponse response ){
Loginform = (loginform) form;
Contactbo userbo = new contactbo ();
// Extract data from the business processing logic class first (arraylist or vector format)
Collection data;
Try {
Data = userbo. findcontact (databaseconn. getconnection ());
// Obtain the current page curpage and the number of records per page pagesize.
// Int curpage = integer. parseint (string) request. getparameter ("cur_page "));
Int curpage = 1;
String cur = request. getparameter ("cur_page ");
System. Out. println ("--------------:" + cur );
If (cur! = NULL & cur! = ""){
Curpage = new INTEGER (cur). intvalue ();
}
Int pagesize = 10;
// Then generate the pageresultset object
Pageresultset datalist = new pageresultset (data, curpage, pagesize );
Request. setattribute ("userslist", datalist );
Return Mapping. findforward ("Sss ");
} Catch (exception e ){
E. printstacktrace ();
Return Mapping. getinputforward ();
}
}
}

3. The following page is displayed. Copy code The Code is as follows: <% @ page Language = "Java" Import = "Java. util. *, page. Bean. Contact, page. Bean. pageresultset"
Pageencoding = "gb2312" %>
<%
String Path = request. getcontextpath ();
String basepath = request. getscheme () + "://"
+ Request. getservername () + ":" + request. getserverport ()
+ Path + "/";
%>
<! Doctype HTML public "-// W3C // dtd html 4.01 transitional // en">
<HTML>
<Head>
<Base href = "<% = basepath %>">
<Title> my JSP 'index. jsp 'starting page </title>
<Meta http-equiv = "Pragma" content = "no-Cache">
<Meta http-equiv = "cache-control" content = "no-Cache">
<Meta http-equiv = "expires" content = "0">
<Meta http-equiv = "keywords" content = "keyword1, keyword2, keyword3">
<Meta http-equiv = "Description" content = "this is my page">
<! --
<LINK rel = "stylesheet" type = "text/CSS" href = "styles.css">
-->
</Head>
<Body>
<Table border = "1">
<%
Pageresultset = (pageresultset) request. getattribute ("userslist ");
Arraylist userslist = (arraylist) pageresultset. getdata ();
For (INT I = 0; I <userslist. Size (); I ++ ){
Contact CO = (contact) userslist. Get (I );
%>
<Tr>
<TD>
<% = Co. GETID () %>
</TD>
<TD>
<A href = "login. do? Id = <% = Co. GETID () %> "> <% = Co. GetUserName () %> </a>
</TD>
<TD>
<% = Co. getmobile () %>
</TD>
<TD>
<% = Co. getmail () %>
</TD>
<TD>
<% = Co. getphone () %>
</TD>
<TD>
<% = Co. getmem () %>
</TD>
<TD>
<% = Co. getlastcontact () %>
</TD>
</Tr>
<%
}
%>
</Table>
<! -- Display pagination toolbar -->
<% = Pageresultset. gettoolbar ("login. Do") %>
</Body>
</Html>