ibatis分页实现（postgresql版）

285572001

　　PagerModel类（通过传递一个查询实体进行查询）

/**
*
*/
package com.audit.util;
import java.util.List;
/**
* @author      chenpeng
* @file_name   PagerModel.java
* @create_time 2010-7-27:下午05:21:16
* @email       onlychenpeng@msn.com
* TODO
*/
public class PagerModel {
//总数
private int total;
//当前页码,默认为1
private int currentPage=1;

//总页数
private int totalPage;
//页面大小,默认为10
private int pageSize;
//开始,默认为0
private int startCount=0;

//当前页面的长度
private int currentSize=0;

//是否存在下一页
private boolean hasNext;

//是否存在上一页
private boolean hasPre;

//ibatis的example查询实体
private Object obj;
//查询出来的数据
private List datas;


/**
* 首页
*/
public void first(){
this.init(1);
}
/**
* 首页,带页面大小
* */
public void first(int pageSize){
this.init(1, pageSize);
}
/**
* 下一页
* */
public void next(){
this.currentPage++;
this.init(this.currentPage);
}

/**
* 上一页
* */
public void pre(){
this.currentPage--;
this.init(this.currentPage);
}
/**
* 最后一页
* */
public void last(){
this.currentPage=this.totalPage;
this.init(this.currentPage);
}

/***/


/**
* 统一初始化所有参数
*/
public void init(int currentPage,int pageSize){
//当传入的数不大于0时,把当前页面设为了1,页面大小设为10
if(currentPage<1){
this.currentPage=1;
}else{
this.currentPage=currentPage;
}
if(pageSize<1){
this.pageSize=10;
}else{
this.pageSize=pageSize;
}
this.startCount=(this.currentPage-1)*this.pageSize;
}
/**
* 统一初始化所有参数
* @param currentPage
*/
public void init(int currentPage){
//当传入的数不大于0时,把当前页面设为了1,页面大小设为10
if(currentPage<1){
this.currentPage=1;
}else{
this.currentPage=currentPage;
}
this.startCount=(this.currentPage-1)*this.pageSize;
}
public void setTotal(int total) {
this.total = total;
//计算出总页数
int a=this.total/this.pageSize;  //商
int b=this.total%this.pageSize;  //余
if(0!=b){
a++;
}
this.totalPage=a;
}

//相应的getter&&setter
public int getStartCount() {
return startCount;
}

public void setStartCount(int startCount) {
this.startCount = startCount;
}

public int getCurrentPage() {
return currentPage;
}

public void setCurrentPage(int currentPage) {
this.currentPage = currentPage;
}

public int getPageSize() {
return pageSize;
}

public void setPageSize(int pageSize) {
this.pageSize = pageSize;
}
public int getTotal() {
return total;
}
public List getDatas() {
return datas;
}

public void setDatas(List datas) {
this.datas = datas;
this.currentSize=datas.size();
}


public int getTotalPage() {
return totalPage;
}

public void setTotalPage(int totalPage) {
this.totalPage = totalPage;
}

public Object getObj() {
return obj;
}

public void setObj(Object obj) {
this.obj = obj;
}
public int getCurrentSize() {
return currentSize;
}
public void setCurrentSize(int currentSize) {
this.currentSize = currentSize;
}
public boolean isHasNext() {
if(this.currentPage<this.totalPage){
return true;
}else {
return false;
}
}
public void setHasNext(boolean hasNext) {
this.hasNext = hasNext;
}
public boolean isHasPre() {
if(this.currentPage>1){
return true;
}else{
return false;
}
}
public void setHasPre(boolean hasPre) {
this.hasPre = hasPre;
}
}

　　 xml文件(要进行两次查询，一个是查询记录总数，一个是返回所有记录)

<!-- 查找总数 -->
<select id="findByExampleCount" parameterClass="PagerModel" resultClass="int">
select count(*) from "fTest"
<dynamic prepend="WHERE">
<isNotNull property="obj" prepend="AND" open="(" close=")" removeFirstPrepend="true">
<isNotNull property="obj.test" prepend="AND">
test like '$obj.test$%'
</isNotNull>
</isNotNull>
</dynamic>
</select>
<!-- 查找记录 -->
<select id="findByExample" parameterClass="PagerModel" resultClass="FTest" cacheModel="fTestCache">
select * from "fTest"
<dynamic prepend="WHERE">
<isNotNull property="obj" prepend="AND" open="(" close=")" removeFirstPrepend="true">
<isNotNull property="obj.test" prepend="AND">
test like '$obj.test$%'
</isNotNull>
</isNotNull>
</dynamic>
limit #pageSize# offset #startCount#
</select>
　　 
　　   DAO类(返回一个PagerModel)
　　 
public PagerModel findByExample(PagerModel pm) throws SQLException{
Integer count=(Integer)sqlMapper.queryForObject("fTest.findByExampleCount",pm);
List datas=sqlMapper.queryForList("fTest.findByExample",pm);
pm.setDatas(datas);
pm.setTotal(count);
return pm;

}
　　单元测试代码

package com.audit.test;
import java.sql.SQLException;

import com.audit.model.dao.IFTestDAO;
import com.audit.model.dao.impl.FTestDAOImpl;
import com.audit.model.domain.FTest;
import com.audit.util.PagerModel;
import junit.framework.TestCase;
/**
* @author      chenpeng
* @file_name   TestPagerModel.java
* @create_time 2010-7-28:下午04:55:43
* @email       onlychenpeng@msn.com
* 测试分页
*/
public class TestPagerModel extends TestCase {
public void testPager(){
PagerModel pm=new PagerModel();
pm.init(3, 3);
FTest test=new FTest();
test.setTest("test");
pm.setObj(test);
IFTestDAO ftDAO=new FTestDAOImpl();
try {
pm=ftDAO.findByExample(pm);
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if(null!=pm){
System.out.println("总记录数:"+pm.getTotal());
System.out.println("总页数:"+pm.getTotalPage());
System.out.println("当前页:"+pm.getCurrentPage());
System.out.println("当前页面长度:"+pm.getCurrentSize());
System.out.println("是否存在上一页:"+pm.isHasPre());
System.out.println("是否存在下一页:"+pm.isHasNext());
}
}
}

　　测试结果:
　　总记录数:21
   总页数:7
   当前页:1
   当前页面长度:3
  是否存在上一页:false
  是否存在下一页:true