拜读了bibiye的《一个高效简洁的Struts分页方法(原创)》后，根据bibiye的方法，自己修改了一下，也弄了一个struts下的分页，大家见笑了！
我的方法是，根据用户点击导航条上的页号(offset)，到DB中读取该页的数据(不是一次全部读出)，点到哪页读哪页的数据，JBX + tomcat + oracle下测试通过，数据库用的表是oracle的emp表。
********分页类Pager.java，负责生成分页导航条********
package page;
/**
* 分页代码
* <p>Title: 分页</p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2005</p>
* <p>Company: BCS</p>
* @author Alex
* @version 1.0
*/
public class Pager {
private int offset;
private int size;
private int length;
private String url;
private String pageHeader;
public Pager(int offset, int size, int length, String url, String pageHeader) {
this.offset = offset;
this.size = size;
this.length = length;
this.url = url;
this.pageHeader = pageHeader;
}
/**
* 返回分页导航条
* @param offset int 起始记录的位置
* @param size int 总记录数
* @param length int 步长
* @param url String .do的url
* @param pageHeader String 导航条的前缀文字提示
* @return String
*/
public String getPageNavigation() {
String pageNavigation = ""; //最终返回的分页导航条
//记录数超过一页,需要分页
if (size > length) {
String pref; //前缀
if (url.indexOf("?") > -1) {
//如果url中已经包含了其他的参数,就把offset参数接在后面
pref = "&";
}
else {
//如果url中没有别的参数
pref = "?";
}
//如果导航条包含header
if (pageHeader != null && pageHeader.length() > 0) {
pageNavigation = pageHeader + " : ";
}
//如果不是第一页,导航条将包含“<<”(第一页)和“<”(前一页)
if (offset > 0) {
pageNavigation += "<a href='" + url + pref + "offset=0'>[<<]</a>\n" +
"<a href='" + url + pref + "offset=" + (offset - length) +
"'>[<]</a>\n";
}
//导航条中,排头的那一页的offset值
int startOffset;
//位于导航条中间的那一页的offset值(半径)
int radius = constants.MAX_PAGE_INDEX / 2 * length;
//如果当前的offset值小于半径
if (offset < radius || this.pageCount() <= constants.MAX_PAGE_INDEX) {
//那么第一页排头
startOffset = 0;
}
else if (offset < size - radius) {
startOffset = offset - radius;
}
else {
startOffset = (size / length - constants.MAX_PAGE_INDEX) * length;
}
for (int i = startOffset;
i < size && i < startOffset + constants.MAX_PAGE_INDEX * length;
i += length) {
if (i == offset) {
//当前页号,加粗显示
pageNavigation += "<b>" + (i / length + 1) + "</b>\n";
}
else {
//其他页号,包含超链接
pageNavigation += "<a href='" + url + pref + "offset=" + i + "'>" +
(i / length + 1) + "</a>\n";
}
}
//如果不是最后一页,导航条将包含“>”(下一页)和“>>”(最后一页)
if (offset < size - length) {
pageNavigation += "<a href='" + url + pref + "offset=" +
(offset + length) + "'>[>]</a>\n" +
"<a href='" + url + pref + "offset=" + lastPageOffset() +
"'>[>>]</a>\n";
}
// System.out.println("radius : " + radius);
// System.out.println("start offset : " + startOffset);
return pageNavigation;
}
//记录不超过一页,不需要分页
else {
return "";
}
}
/**
* 返回分页后的总页数
* @param size int 总记录数
* @param length int 每页的记录数
* @return int
*/
public int pageCount() {
int pagecount = 0;
if (size % length == 0) {
pagecount = size / length;
}
else {
pagecount = size / length + 1;
}
return pagecount;
}
/**
* 返回最后一页的记录数
* @param size int 总记录数
* @param length int 每页的记录数
* @return int
*/
public int lastPageSize() {
int lastpagesize = 0;
if (size % length == 0) {
lastpagesize = length;
}
else {
lastpagesize = size % length;
}
return lastpagesize;
}
/**
* 返回最后一页的起始记录位置
* @param size int 总记录数
* @param length int 每页的记录数
* @return int
*/
public int lastPageOffset() {
return size - lastPageSize();
}
public int getOffset() {
return offset;
}
public void setOffset(int offset) {
this.offset = offset;
}
public int getSize() {
return size;
}
public void setSize(int size) {
this.size = size;
}
public int getLength() {
return length;
}
public void setLength(int length) {
this.length = length;
}
public String getUrl() {
return url;
}
public void setUrl(String url) {
this.url = url;
}
public String getPageHeader() {
return pageHeader;
}
public void setPageHeader(String pageHeader) {
this.pageHeader = pageHeader;
}
}
********数据处理类empDAO.java，负责访问DB，获取当前页面需要显示的记录********
package page;
import java.sql.*;
import java.util.*;
public class empDAO {
public empDAO() {
}
/**
* 从offset位置起始,返回length条记录
* @param offset int 起始的记录位置
* @param length int 步长
* @param conn Connection 数据库连接
* @return ArrayList
*/
public ArrayList findAllEmp(int offset, int length, Connection conn) throws
SQLException {
PreparedStatement ps = null;
ResultSet rs = null;
ArrayList emps = new ArrayList();
empVO empvo = null;
String strSql = "select empno, ename from emp where rowid not in (select rowid from emp where rownum <= ?) and rownum <= ?";
try {
ps = conn.prepareStatement(strSql);
ps.setInt(1, offset); //起始记录的位置
ps.setInt(2, length); //步长
rs = ps.executeQuery();
while (rs != null && rs.next()) {
empvo = new empVO();
empvo.setEmpno(rs.getInt("empno"));
empvo.setEname(rs.getString("ename"));
emps.add(empvo);
}
}
catch (SQLException ex) {
ex.printStackTrace();
throw ex;
}
return emps;
}
/**
* 返回总的记录数
* @param conn Connection
* @throws SQLException
* @return int
*/
public int getRsTotalCount(Connection conn) throws SQLException {
PreparedStatement ps = null;
ResultSet rs = null;
int rsCount = 0;
String strSql = "select count(empno) as empCount from emp";
try {
ps = conn.prepareStatement(strSql);
rs = ps.executeQuery();
if (rs != null && rs.next()) {
rsCount = rs.getInt("empCount");
}
}
catch (SQLException ex) {
ex.printStackTrace();
throw ex;
}
return rsCount;
}
}
********业务类empBO.java，调用empDAO类********
package page;
import java.util.*;
/**
* BO类
* <p>Title: 分页</p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2005</p>
* <p>Company: BCS</p>
* @author Alex
* @version 1.0
*/
public class empBO {
private DBPool db = DBPool.newInstance();
private empDAO empdao = new empDAO();
public empBO() {
}
/**
* 从offset位置起始,返回length条记录
* @param offset int 起始
* @param length int 步长
* @throws Exception
* @return ArrayList
*/
public ArrayList findAllEmp(int offset, int length) throws Exception {
ArrayList emps = new ArrayList();
try {
emps = empdao.findAllEmp(offset, length, db.getConnection());
}
catch (Exception ex) {
throw ex;
}
finally {
db.release();
}
return emps;
}
/**
* 返回总的记录数
* @throws Exception
* @return int
*/
public int getRsTotalCount() throws Exception {
int rsCount = 0;
try {
rsCount = empdao.getRsTotalCount(db.getConnection());
}
catch (Exception ex) {
throw ex;
}
finally {
db.release();
}
return rsCount;
}
}
********ActionForm类empForm.java********
package page;
import javax.servlet.http.*;
import org.apache.struts.action.*;
public class empForm
extends ActionForm {
private int offset; //起始记录的位置//每页显示的记录数
public ActionErrors validate(ActionMapping actionMapping,
HttpServletRequest httpServletRequest) {
/**@todo: finish this method, this is just the skeleton.*/
return null;
}
public void reset(ActionMapping actionMapping,
HttpServletRequest httpServletRequest) {
this.offset = 0; //记录默认从第一条开始显示
}
public int getOffset() {
return offset;
}
public void setOffset(int offset) {
this.offset = offset;
}
}
********Action类empAction.java，控制器，调用BO类，Pager类********
package page;
import java.util.*;
import javax.servlet.http.*;
import org.apache.struts.action.*;
/**
* 分页测试的Action
* <p>Title: 分页</p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2005</p>
* <p>Company: BCS</p>
* @author Alex
* @version 1.0
*/
public class empAction
extends Action {
public ActionForward execute(ActionMapping actionMapping,
ActionForm actionForm,
HttpServletRequest httpServletRequest,
HttpServletResponse httpServletResponse) {
empForm empform = (empForm) actionForm;
return performList(actionMapping, actionForm, httpServletRequest,
httpServletResponse);
}
private ActionForward performList(ActionMapping actionMapping,
ActionForm actionForm,
HttpServletRequest request,
HttpServletResponse response) {
try {
empBO empbo = new empBO();
//获取外部传进来的起始记录号
int offset = ( (empForm) actionForm).getOffset();
//获取每页的记录数
int pagesize = constants.PAGE_SIZE;
//获取记录集合,从offset开始,取length条记录
ArrayList emps = empbo.findAllEmp(offset, pagesize);
//计算所有记录的条数(总记录数)
int size = empbo.getRsTotalCount();
//外部url地址,得到形如: http://localhost:8088/bugMIS/showlist.do 的String
String url = request.getContextPath() + actionMapping.getPath() + ".do";
//实例化分页类
Pager p = new Pager(offset, size, pagesize, url, "Page Navigation");
//获取分页导航条
//String pageNavigation = p.getPageNavigation();
//将url字符串和记录集合,存入request中
request.setAttribute("pager", p);
request.setAttribute("emps", emps);
}
catch (Exception e) {
e.printStackTrace();
return actionMapping.findForward("failure");
}
return actionMapping.findForward("success");
}
}
********数据库连接池类DBPool.java，可以使用tomcat的连接池，也可以不用，这里关闭了********
package page;
import java.sql.*;
import javax.naming.*;
import javax.sql.*;
import org.apache.commons.logging.*;
/**
* 系统连接池类
* <p>Title:
Gantoo@91.com</p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2005</p>
* <p>Company: BCS</p>
* @author Alex
* @version 1.0
*/
public class DBPool {
Log log = LogFactory.getLog("DBPool"); //日志机
private DBPool() {
}
private Connection conn = null;
/* true:使用连接池
false:不使用连接池,采用JDBC直接连接 */
private final static boolean USE_DB_POOL = false;
private final static String jndi_DataSource = "jdbc/BugMIS_ora";
private final static String jdbcdriver =
"oracle.jdbc.driver.OracleDriver";
private final static String url =
"jdbc:oracle:thin:@localhost:1521:myo9";
private final static String user = "scott";
private final static String pass = "tiger";
public static DBPool newInstance() {
return new DBPool();
}
/**
* 切换是否使用连接池
* */
public Connection getConnection() {
if (USE_DB_POOL) {
conn = getConnectionByDBPool();
}
else {
conn = getConnectionDirect();
}
return conn;
}
/**
* 直接采用JDBC连接数据库
* */
private Connection getConnectionDirect() {
try {
Class.forName(jdbcdriver).newInstance();
conn = DriverManager.getConnection(url, user, pass);
}
catch (SQLException ex) {
log.error("Error Connection! " + ex.getMessage());
}
catch (ClassNotFoundException ex) {
log.error("Driver Not Found! " + ex.getMessage());
}
catch (IllegalAccessException ex) {
log.error(ex.getMessage());
}
catch (InstantiationException ex) {
log.error(ex.getMessage());
}
return conn;
}
/**
* 采用连接池
* */
private Connection getConnectionByDBPool() {
try {
Context initCtx = new InitialContext();
Context ctx = (Context) initCtx.lookup("java:/comp/env");
DataSource ds = (DataSource) ctx.lookup(jndi_DataSource);
conn = ds.getConnection();
}
catch (NamingException ex) {
log.error("Data Source Not Found! " + ex.getMessage());
//System.out.println("未找到数据源" + ex.getMessage());
}
catch (SQLException ex1) {
log.error("Error Connection! " + ex1.getMessage());
//System.out.println("错误的数据连接" + ex1.getMessage());
}
return conn;
}
/**
* 释放连接
* */
public void release() {
try {
if (!conn.isClosed()) {
conn.close();
}
}
catch (SQLException ex) {
log.error("Connection Closing Error! " + ex.getMessage());
//System.out.println("连接关闭失败" + ex.getMessage());
}
}
}
********包含常量的类constants.java，常量********
package page;
/**
* 定义工程中公用的常量
* <p>Title: 分页</p>
* <p>Description: </p>
* <p>Copyright: Copyright (c) 2005</p>
* <p>Company: BCS</p>
* @author Alex
* @version 1.0
*/
public final class constants {
public static final int MAX_PAGE_INDEX = 5; //页脚显示多少页
public static final int PAGE_SIZE = 2; //每页的记录数
}
********测试jsp页面index.jsp，为了方便测试，嵌入了java代码，能显示就行********
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ page contentType="text/html; charset=GBK" import="java.util.*,page.*"%>
<html:html>
<head>
<title></title>
<style type="text/css">
.pt9 { font: 10pt "宋体"}
body { font: 10pt "宋体" ; margin: 15px}
td { font-size: 10pt}
a:hover { font-size: 10pt; color: red; text-decoration: underline}
a:link { font-size: 10pt; color: blue; text-decoration: underline}
a:active { font-size: 10pt; color: blue; text-decoration: underline}
a:visited { font-size: 10pt; color: blue; text-decoration: underline }
</style>
</head>
<body bgcolor="#ffffff">
<p><a href="http://localhost:8088/page/showEmp.do?offset=0">Show Me All Of The Emps</a></p>
<logic:present name="emps">
<%
ArrayList emps = (ArrayList)request.getAttribute("emps");
Iterator it = emps.iterator();
empVO empvo;
while(it!=null && it.hasNext()){
empvo = (empVO)it.next();
out.print(empvo.getEmpno() + " ");
out.print(empvo.getEname() + "<br>");
}
out.print("当前页有 " + emps.size() + " 条记录<br>");
out.print("<p>");
%>
</logic:present>
<logic:present name="pager">
<%
Pager pager = (Pager)request.getAttribute("pager");
out.print(pager.getPageNavigation() + "<p>");
out.print("共有记录 " + pager.getSize() + " 条<br>");
out.print("每页有 " + pager.getLength() + " 条记录<br>");
out.print("共分 " + pager.pageCount() + " 页<br>");
%>
</logic:present>
</body>
</html:html>
********配置文件struts-config.xml********
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.1//EN" "http://jakarta.apache.org/struts/dtds/struts-config_1_1.dtd">
<struts-config>
<form-beans>
<form-bean name="empForm" type="page.empForm" />
</form-beans>
<action-mappings>
<action input="/index.jsp" name="empForm" path="/showEmp" scope="request" type="page.empAction" validate="false">
<forward name="faiure" path="/index.jsp" />
<forward name="success" path="/index.jsp" />
</action>
</action-mappings>
</struts-config>
在网上看了几个Structs分页，感觉不是很完善，于是根据自己的经验，写了一个相对高效简洁的分页方法。由于本人水平有限，如果大家有什么更好的想法，欢迎不吝赐教。
一、 开发环境
我的开发环境是：JBuilder x + Weblogic 8.1 + Oracle 9i + Windows 2003 ，如果朋友们的开发环境不一样亦无妨。
二、开发思路
既然讲的是Struts，那自然离不了MVC，分页显示也是如此。
1、 建立数据库和对应的表，本例的表是TCertificate。
2、 建立适当的模型组件，对应你要查询数据库中的表。这部分由DAO数据访问层来实现，如果有的朋友对DAO不熟悉可以查询一下相关资料。本例由CertificateDAO.java来实现。
3 、建立分页所需要的模型组件，由javaBean来充当，并与CertificateDAO实现分离。网上介绍的很多方法，都存在着数据与分页组件藕合的现象，这也是本方法与其它分页方法的主要不同之处。
4、建立控制器组件，这部分由Struts 中的Action来实现。主要负责将实例化CertificateDAO，只取要显示的数据记录，存入ArrayList对象然后返回，并放到request中。而分页部分则根据分页条件，单独进行构造，避免了与DAO混在一起的情况发生。网上其它介绍的一些分页方法中，基本上都是一次性读出所有查询的数据，然后再由分页相关组件进行构造。这样，如果数据量大的话，很容易形成瓶颈。在本例中由于不是一次性地读出查询的所有数据，而只是读出一个页面要显示的数据记录，这就节省了很多不必要的数据传输，提高了效率。本例中为CertificateAction.java。
5、建立视图组件，这部分由jsp来充当，为了不出现java 代码，我们使用Struts提供的标签库，主要负责从request中取出刚刚放入的对象，通过反复调用CertificateAction以及action参数，而实现分页显示。本例中为listcertificate.jsp。
6、 建立并配置struts-config.xml。
三、实例代码
确定好上面的开发思路后，代码的实现就有单可循了。
1、建数据库和相应的表。
2、数据逻辑层的相关代码。
1）、通用的DAO类：CommonDAO.java
这是一个很多DAO都要继承到的通用DAO类，是我根据实践总结出来的，为了减少篇幅，这里只显示和本例相关的代码。
java代码:
代码：
--------------------------------------------------------------------------------
package com.xindeco.business ;
import java.io.*;
import java.sql.*;
import java.util.*;
import javax.sql.*;
import java.lang.IllegalAccessException;
import java.lang.reflect.InvocationTargetException;
import org.apache.commons.beanutils.BeanUtils;
public class DAO
{
protected DataSource ds;
/**
* 说明:取得当前查询的总记录数
*/
public int getRows ()
{
return this.count;
}
public void rsHandler (ResultSet rs, int offset, int limit)
{
try
{
count = 0;
rs.absolute ( -1) ;
count = rs.getRow () ;
if (offset <= 0)
{
rs.beforeFirst () ;
}
else
{
rs.absolute (offset) ;
}
}
catch (Exception e)
{
e.printStackTrace () ;
}
}
public DAO(DataSource ds) {
this.ds = ds;
}
public void setDataSource(DataSource ds) {
this.ds = ds;
}
protected void close(ResultSet rs) {
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
}
rs = null;
}
}
protected void close(PreparedStatement pstmt) {
if (pstmt != null) {
try {
pstmt.close();
} catch (SQLException e) {
}
pstmt = null;
}
}
protected void close(Connection conn) {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
protected void rollback(Connection conn) {
if (conn != null) {
try {
conn.rollback();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
}
这个类主要是通过子类传进来的先进结果集，取得查询的记录总数，并对数据库连接进行简单的管理。
2）、对数据库进行访问：CertificateDAO.java
java代码:
代码：
--------------------------------------------------------------------------------
package com.xindeco.business;
import java.io.*;
import java.sql.*;
import java.util.*;
import javax.sql.*;
import com.xindeco.common.dbconn.DbConn;
public class CertificateDAO extends DAO
{
public NationDAO(DataSource ds) {
super(ds);
}
public List findCertificateList(int offset,int limit) throws SQLException
{
int countRows = 0 ;
ArrayList list = null ;
Connection conn = null;
PreparedStatement pstmt = null;
ResultSet rs = null;
try
{
conn = ds.getConnection();
String sql =
"SELECT certificateID, certificateCode,certificateName,photoURL,"
+ "description,graduateID FROM TCertificate " ;
pstmt = conn.prepareStatement(sql);
rs = pstmt.executeQuery();
/*对游标进行处理，rsHandler 方法在父类DAO中*/
this.rsHandler(rs,offset,limit);
if (rs != null && rs.next ())
{
list = new ArrayList () ;
do
{
countRows++ ;
list.add (rs2VO (rs)) ;
}
while ( (countRows++ < limit) && rs.next ()) ;
}
close(rs);
close(pstmt);
} catch (SQLException e) {
close(rs);
close(pstmt);
rollback(conn);
e.printStackTrace();
}
finally {
close(conn);
}
return list ;
}
private CertificateVO rs2VO (ResultSet rs)
{
try
{
CertificateVO certificateVO = new CertificateVO () ;
certificateVO.setCertificateID (rs.getInt ("certificateID")) ;
certificateVO.setCertificateCode (rs.getString ("certificateCode")) ;
certificateVO.setCertificateName (rs.getString ("certificateName")) ;
certificateVO.setPhotoURL (rs.getString ("photoURL")) ;
certificateVO.setDescription (rs.getString ("description")) ;
certificateVO.setGraduateID (rs.getInt ("graduateID")) ;
return certificateVO ;
}
catch (Exception ex)
{
ex.printStackTrace () ;
return null ;
}
}
}
findCertificateList(int offset,int limit)是查得所有要显示的数据，并放入ArrayList中。看过网上有些例子，把数据记录放入ArrayList的动作过程直接在while循环体里完成，如果字段多的话，会造成方法过于宠大，又不美观。 这里，数据记录放入ArrayList的动作过程由rs2VO方法完成，就比较整洁了。另外，if (rs != null && rs.next ()) 配合while ( (countRows++ < limit) && rs.next ()) 是为了程序的健壮性考虑的，稍分析一下不难得出结论。
3、建立控制器组件：CertificateAction.java
java代码:
代码：
--------------------------------------------------------------------------------
package com.xindeco.presentation;
import javax.sql.* ;
import java.util.* ;
import javax.servlet.http.* ;
import javax.servlet.* ;
import org.apache.struts.action.* ;
import org.apache.struts.util.* ;
import com.xindeco.common.Pager;
import com.xindeco.business.graduatedata.CertificateDAO ;
public class CertificateAction
extends Action
{
private static final int PAGE_LENGTH = 5 ; //每页显示5条记录
public ActionForward execute (ActionMapping mapping, Actionform form,
HttpServletRequest request,
HttpServletResponse response)
{
ActionForward myforward = null ;
String myaction = mapping.getParameter () ;
if (isCancelled (request))
{
return mapping.findForward ("failure") ;
}
if ("".equalsIgnoreCase (myaction))
{
myforward = mapping.findForward ("failure") ;
}
else if ("LIST".equalsIgnoreCase (myaction))
{
myforward = performList (mapping, form, request, response) ;
}
else
{
myforward = mapping.findForward ("failure") ;
}
return myforward ;
}
private ActionForward performList (ActionMapping mapping,
Actionform actionform,
HttpServletRequest request,
HttpServletResponse response)
{
try
{
DataSource ds = (DataSource) servlet.getServletContext().getAttribute(Action.DATA_SOURCE_KEY);
CertificateDAO certificateDAO = new CertificateDAO (ds) ;
int offset = 0; //翻页时的起始记录所在游标
int length = PAGE_LENGTH;
String pageOffset = request.getParameter("pager.offset");
if (pageOffset == null || pageOffset.equals("")) {
offset = 0;
} else {
offset = Integer.parseInt(pageOffset);
}
List certificateList = certificateDAO .findCertificateList (offset,length) ;
int size = certificateDAO.getRows(); // 取得总记录数
String url = request.getContextPath()+"/"+mapping.getPath()+".do";
String pagerHeader = Pager.generate(offset, size, length, url); //分页处理
request.setAttribute ("pager", pagerHeader) ;
request.setAttribute ("list", certificateList) ;
}
catch (Exception e)
{
e.printStackTrace();
return mapping.findForward ("error") ;
}
return mapping.findForward ("success") ;
}
}
CertificateAction.java主要是把数据从DAO中取出，并放入一个ArrayList 中，然后通过配置文件再软件View的JSP页。
5、建立视图listcertificate.jsp文件。
jsp代码:
代码：
--------------------------------------------------------------------------------
<%@ page contentType="text/html; charset=GBK" %>
<%@ taglib uri="/WEB-INF/struts-template.tld" prefix="template" %>
<%@ taglib uri="/WEB-INF/struts-html.tld" prefix="html" %>
<%@ taglib uri="/WEB-INF/struts-bean.tld" prefix="bean" %>
<%@ taglib uri="/WEB-INF/struts-logic.tld" prefix="logic" %>
<table bgcolor="#666666" cellpadding="1" cellspacing="0" border="0" width="500">
<tr>
<td>
<table cellpadding="0" cellspacing="0" border="0" width="500">
<tr>
<td bgcolor="#fecc51">&</td>
</tr>
</table>
</td>
</tr>
<tr>
<td>
<table cellpadding="0" cellspacing="0" border="0" width="500">
<tr>
<td bgcolor="#d6e0ed">
&&<bean:message key="label.list4certificate"/>
</td>
</tr>
<tr bgcolor="#FFFFFF">
<td width="5%"></td><td width="19%"></td><td width="76%"></td>
</tr>
<tr>
<td>
<table bgcolor="#f2f2f2" width="500" cellspacing="0" border="0">
<tr bgcolor="#bacce1">
<td><b><bean:message key="Certificate.select"/> </b></td>
<td><b><bean:message key="Certificate.certificateID"/> </b></td>
<td><b><bean:message key="Certificate.certificateCode"/></b></td>
<td><b><bean:message key="Certificate.certificateName"/></b></td>
<td><b><bean:message key="Certificate.view"/></b></td>
</tr>
<bean:write name="pager" property="description"/>
<logic:equal name="pager" property="hasPrevious" value="true">
<a href="/graduatedata/list.do?viewPage=<bean:write name="pager" property="previousPage"/>" class="a02">
Previous
</a>
</logic:equal>
<logic:equal name="pager" property="hasNext" value="true">
<a href="/graduatedata/list.do?viewPage=<bean:write name="pager" property="nextPage"/>" class="a02">
Next
</a>
</logic:equal>
<logic:notEmpty name="list" scope="request">
<logic:iterate id="certificate" name="list" type="com.xindeco.business.graduatedata.CertificateVO"scope="request">
<tr bgcolor="#FFFFFF">
<td><html:text property="name" value="<bean:write name="certificate" property="certificateID" scope="page"/>"/>
</td>
<td> <bean:write name="certificate" property="certificateID" scope="page"/></td>
<td> <bean:write name="certificate" property="certificateCode" scope="page"/></td>
<td> <bean:write name="certificate" property="certificateName" scope="page"/></td>
<td> <bean:write name="certificate" property="photoURL" scope="page"/></td>
</tr>
</logic:iterate>
</logic:notEmpty>
</table>
</td>
</tr>
</table>
</td>
</tr>
</table>
6、对应的配置文件struts-config.xml。
java代码:
代码：
--------------------------------------------------------------------------------
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts-config PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 1.1//EN" "http://jakarta.apache.org/struts/dtds/struts-config_1_1.dtd">
<struts-config>
<form-beans>
<form-bean name="certificateform" type="com.xindeco.presentation.graduatedata.Certificateform" />
</form-beans>
<global-forwards>
<forward name="error" path="/error/error.jsp" />
</global-forwards>
<action-mappings>
<action name="certificateform" parameter="LIST" path="/graduatedata/list" scope="request" type="com.xindeco.presentation.graduatedata.CertificateAction" validate="true">
<forward name="success" path="/graduatedata/listcertificate.jsp" />
</action>
</action-mappings>
……
</struts-config>
7、最后当然是最重要的分页代码了：Pager.java
java代码:
代码：
--------------------------------------------------------------------------------
package com.xindeco.common;
import java.util.* ;
public class Pager {
private static int MAX_PAGE_INDEX = 10; //页脚显示多少页
private static String HEADER = "Result page";
public static String generate(int offset, int length, int size, String url) {
if (length > size) {
String pref;
if (url.indexOf("?") > -1) {
pref = "&";
} else {
pref = "?";
}
String header = "<font face='Helvetica' size='-1'>"+HEADER+": ";
if (offset > 0) {
header += "&<a href=\""+url+pref+"pager.offset="+(offset-size)+"\">[<< Prev]</a>\n";
}
int start;
int radius = MAX_PAGE_INDEX/2*size;
if (offset < radius) {
start = 0;
} else if(offset < length-radius) {
start = offset - radius;
} else {
start = (length/size-MAX_PAGE_INDEX)*size;
}
for(int i=start;i<length && i < start + MAX_PAGE_INDEX*size;i+=size) {
if (i == offset) {
header += "<b>"+(i/size+1)+"</b>\n";
} else {
header += "&<a href=\""+url+pref+"pager.offset="+i+"\">"+(i/size+1)+"</a>\n";
}
}
if(offset < length - size) {
header += "&<a href=\""+url+pref+"pager.offset="+((int)offset+(int)size)+"\">[Next >>]</a>\n";
}
header += "</font>";
return header;
} else {
return "";
}
}
}
这部分代码的实现相当简洁，但已经足够完成所需了。