SSH一个分页功能,从bean容器注入值的时候在action中接受到的service层报空值,但是自己觉得配置方面没有问题,求大神解释
package com.test.bean;
import java.util.List;
/*
bean容器
*/
public class PageBean {
private List list; //要返回的某一页的记录列表
private int allRow; //总记录数
private int totalPage; //总页数
private int currentPage; //当前页
private static int pageSize; //每页记录数
private boolean isFirstPage; //是否为第一页
private boolean isLastPage; //是否为最后一页
private boolean hasPreviousPage; //是否有前一页
private boolean hasNextPage; //是否有下一页
public List getList() {
return list;
}
public void setList(List list) {
this.list = list;
}
public int getAllRow() {
return allRow;
}
public void setAllRow(int allRow) {
this.allRow = allRow;
}
public int getTotalPage() {
return totalPage;
}
public void setTotalPage(int totalPage) {
this.totalPage = totalPage;
}
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;
}
/** *//**
* 初始化分页信息
*/
public void init(){
this.isFirstPage=isFirstPage;
this.isLastPage=isLastPage;
this.hasNextPage=hasNextPage;
this.hasPreviousPage=hasPreviousPage;
}
/** *//**
* 以下判断页的信息,只需getter方法(is方法)即可
* @return
*/
public boolean isFirstPage() {
return currentPage == 1; // 如是当前页是第1页
}
public boolean isLastPage() {
return currentPage == totalPage; //如果当前页是最后一页
}
public boolean isHasPreviousPage() {
return currentPage != 1; //只要当前页不是第1页
}
public boolean isHasNextPage() {
return currentPage != totalPage; //只要当前页不是最后1页
}
/** *//**
* 计算总页数,静态方法,供外部直接通过类名调用
* @param pageSize 每页记录数
* @param allRow 总记录数
* @return 总页数
* @param totalPage 总页数
*/
public static int countTotalPage(final int PageSize,final int allRow){
int totalPage = allRow % pageSize == 0 ? allRow/pageSize : allRow/pageSize+1;
return totalPage;
}
/** *//**
* 计算当前页开始记录
* @param pageSize 每页记录数
* @param currentPage 当前第几页
* @return offset 当前页开始记录号
*/
public static int countOffset(final int pageSize,final int currentPage){
final int offset = pageSize*(currentPage-1);
return offset;
}
/** *//**
* 计算当前页,若为0或者请求的URL中没有"?page=",则用1代替
* @param page 传入的参数(可能为空,即0,则返回1)
* @return 当前页
*/
public static int countCurrentPage(int page){
final int curPage=(page==0?1:page);
return curPage;
}
}
/*
dao层
*/
package com.test.dao;
import java.util.List;
public interface MemberDao {
//省略了其他的代码
/** *//**
* 分页查询
* @param hql 查询的条件
* @param offset 开始记录
* @param length 一次查询几条记录
* @return
*/
public List queryForPage(final String hql,final int offset, int length);
/** *//**
* 查询所有记录数
* @param hql 查询的条件
* @return 总记录数
*/
public int getAllRowCount(String hql);
}
/*
道的实现类
*/
package com.test.dao.impl;
import java.util.List;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import com.test.dao.MemberDao;
public class MemberDaoImpl implements MemberDao {
/** *//**
* 分页查询
* @param hql 查询的条件
* @param offset 开始记录
* @param length 一次查询几条记录
* @return
*/
private SessionFactory sessionFactory;
public void setSessionFactory(SessionFactory sessionFactory) {
this.sessionFactory = sessionFactory;
}
public List queryForPage(final String hql, final int offset, final int length) {
// TODO Auto-generated method stub
Session session=sessionFactory.openSession();
Query q =session.createQuery(hql);
q.setFirstResult(offset);
q.setMaxResults(length);
List list=q.list();
System.out.println(list.size());
session.close();
return list;
}
public int getAllRowCount(String hql) {
// TODO Auto-generated method stub
Session session=sessionFactory.openSession();
return session.createQuery(hql).list().size();
}
}
/*
service 层
*/
package com.test.service;
import com.test.bean.PageBean;
public interface MemberService {
/** *//**
* 分页查询
* @param currentPage 当前第几页
* @param pageSize 每页大小
* @return 封闭了分页信息(包括记录集list)的Bean
*/
public PageBean queryForPage(int pageSize,int currentPage);
}
/*
service实现类
*/
package com.test.service.impl;
import java.util.List;
import org.junit.Test;
import com.test.bean.PageBean;
import com.test.bean.User;
import com.test.dao.MemberDao;
import com.test.service.MemberService;
public class MemberServiceImpl implements MemberService {
//通过applicationContext.xml配置文件注入MemberDao的值
private MemberDao memberDao;
public void setMemberDao(MemberDao memberDao) {
this.memberDao = memberDao;
}
/** *//**
* 分页查询
* @param page 当前第几页
* @param pageSize 每页大小
* @return 封闭了分页信息(包括记录集list)的Bean
*/
public PageBean queryForPage(int pageSize, int page) {
// TODO Auto-generated method stub
final String hql = "from User user order by user.id desc"; //查询语句
int allRow = memberDao.getAllRowCount(hql); //总记录数
int totalPage = PageBean.countTotalPage(pageSize, allRow); //总页数
final int offset = PageBean.countOffset(pageSize, page); //当前页开始记录
final int length = pageSize; //每页记录数
final int currentPage = PageBean.countCurrentPage(page);
List<User> list = memberDao.queryForPage(hql,offset, length); //"一页"的记录
System.out.println(allRow+" "+totalPage+" "+offset+length+" "+currentPage);
PageBean pageBean=new PageBean();
pageBean.setPageSize(pageSize);
pageBean.setCurrentPage(currentPage);
pageBean.setAllRow(allRow);
pageBean.setTotalPage(totalPage);
pageBean.setList(list);
pageBean.init();
return pageBean;
}
}
/*
action 层
*/
package com.test.action.user;
import java.util.List;
import org.junit.Test;
import com.test.bean.PageBean;
import com.test.bean.User;
import com.test.service.MemberService;
public class ListMember {
private MemberService memberService;
private List<User> listUser;
public List<User> getListUser() {
return listUser;
}
public void setListUser(List<User> listUser) {
this.listUser = listUser;
}
public void setMemberService(MemberService memberService) {
this.memberService = memberService;
}
private int page=1;
private PageBean pageBean;
public int getPage() {
return page;
}
public void setPage(int page) {
this.page = page;
}
public PageBean getPageBean() {
return pageBean;
}
public void setPageBean(PageBean pageBean) {
this.pageBean = pageBean;
}
@Test
public String findfy() throws Exception{
//分页的pageBean,参数pageSize表示每页显示记录数,page为当前页
System.out.println(memberService.hashCode());
this.pageBean= memberService.queryForPage(2, page);
this.listUser=this.pageBean.getList();
return "success";
}
}
<action name="pageNum" class="com.test.action.user.ListMember" method="findfy">
<result name="success" type="redirect">/listMember.jsp</result>
</action>
数据库连接池的配置正确
<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource"
destroy-method="close">
<property name="driverClassName">
<value>com.mysql.jdbc.Driver</value>
</property>
<property name="url">
<value>jdbc:mysql://localhost:3306/ssh2</value>
</property>
<property name="username">
<value>root</value>
</property>
<property name="password">
<value>root</value>
</property>
</bean>
<bean id="sessionFactory" class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
<property name="dataSource">
<ref local="dataSource" />
</property>
<property name="mappingResources">
<list>
<value>com/test/bean/User.hbm.xml</value>
</list>
</property>
<property name="hibernateProperties">
<props>
<prop key="hibernate.dialect">
org.hibernate.dialect.MySQLDialect
</prop>
<prop key="hibernate.show_sql">true</prop>
</props>
</property>
</bean>
<!-- 分页注入值 -->
<bean id="MemberDao" class="com.test.dao.impl.MemberDaoImpl" scope="singleton">
<property name="sessionFactory" ref="sessionFactory"></property>
</bean>
<bean id="MemberService" class="com.test.service.impl.MemberServiceImpl">
<property name="memberDao" ref="MemberDao"></property>
</bean>
<bean id="pageAction" class="com.test.action.user.ListMember">
<property name="memberService" ref="MemberService"></property>
</bean>