SSH2简单实现分页效果

淡淡的烟草味﹌ 2022-05-18 03:19 261阅读 0赞

1、首先数据库部分：字段类型全字符串

![70][]

2、部署spring、hibernate、struts2、导包建path，新建包，生成pojo及映射文件，目录如下

![70 1][]

3、在tools包下编写分页工具bean类

package com.tools;
    
    public class Paging {
    	private int pageNow;//当前页
    	private int pageSize;//每页显示数
    	private int totalRecords;//总记录数
    	private int totalPages;//总页数
    	
    	private boolean hasFirst;//是否有首页
    	private boolean hasLast;//是否有尾页
    	private boolean hasPre;//是否有前一页
    	private boolean hasNext;//是否有后一页
    	
    	public Paging(){}
    	
    	public Paging(int pageNow,int pageSize,int totalRecords){
    		this.pageNow=pageNow;
    		this.pageSize=pageSize;
    		this.totalRecords=totalRecords;	//构造器为变量赋值
    	}
    	
    	public int getPageNow() {
    		return pageNow;
    	}
    	public void setPageNow(int pageNow) {
    		this.pageNow = pageNow;
    	}
    	public int getPageSize() {
    		return pageSize;	
    	}
    	public void setPageSize(int pageSize) {
    		this.pageSize = pageSize;
    	}
    	public int getTotalRecords() {
    		return totalRecords;
    	}
    	public void setTotalRecords(int totalRecords) {
    		this.totalRecords = totalRecords;
    	}
    	public int getTotalPages() {
    		if(totalRecords%pageSize!=0)
    			return totalRecords/pageSize+1;
    		else
    			return totalRecords/pageSize;
    		//return (pageSize+totalRecords-1)/pageSize;//总页数计算
    	}
    	public void setTotalPages(int totalPages) {
    		this.totalPages = totalPages;
    	}
    	public boolean isHasFirst() {
    		if(pageNow==1)			//如果当前页是1，则没有首页
    			return false;
    		else
    			return true;
    	}
    	public void setHasFirst(boolean hasFirst) {
    		this.hasFirst = hasFirst;
    	}
    	public boolean isHasLast() {
    		if(pageNow==this.getTotalPages())	//如果当前页是总页数，则没有尾页
    			return false;
    		else
    			return true;
    	}
    	public void setHasLast(boolean hasLast) {
    		this.hasLast = hasLast;
    	}
    	public boolean isHasPre() {
    		if(pageNow==1)			//如果当前页是1，则没有前一页
    			return false;
    		else
    			return true;
    	}
    	public void setHasPre(boolean hasPre) {
    		this.hasPre = hasPre;
    	}
    	public boolean isHasNext() {
    		if(pageNow==this.getTotalPages())	//如果当前页是总页数，则没有后一页
    			return false;
    		else
    			return true;
    	}
    	public void setHasNext(boolean hasNext) {
    		this.hasNext = hasNext;
    	}
    
    	@Override
    	public String toString() {
    		return "Paging [pageNow=" + pageNow + ", pageSize=" + pageSize + ", totalRecords=" + totalRecords
    				+ ", totalPages=" + totalPages + ", hasFirst=" + hasFirst + ", hasLast=" + hasLast + ", hasPre="
    				+ hasPre + ", hasNext=" + hasNext + "]";
    	}
    }

4、在service包下编写业务方法

![70 2][]

package com.service;
    
    import java.util.List;
    
    import com.model.Studentsinfo;
    
    public interface InterPagingService {
    
    	public int findTotalRecords();	//查找总记录条数业务方法
    	
    	public List<Studentsinfo> findShowRecords(int pageNow,int pageSize);	//查找需要显示的记录业务方法
    }

package com.service;
    
    import java.util.List;
    
    import com.dao.InterPagingDao;
    import com.model.Studentsinfo;
    
    public class PagingServiceImpl implements InterPagingService {
    
    	private InterPagingDao pagingDaoImpl;
    	
    	public InterPagingDao getPagingDaoImpl() {
    		return pagingDaoImpl;
    	}
    	public void setPagingDaoImpl(InterPagingDao pagingDaoImpl) {
    		this.pagingDaoImpl = pagingDaoImpl;
    	}
    	
    	@Override
    	public int findTotalRecords() {		
    		return pagingDaoImpl.findTotalRecordsDao();
    	}
    	
    	public List<Studentsinfo> findShowRecords(int pageNow,int pageSize){
    		int skipRecords=(pageNow-1)*pageSize;	//数据库查询跳过的记录数
    		return pagingDaoImpl.findShowRecordsDao(skipRecords,pageSize);
    	}
    
    }

5、dao包下编写数据库的操作

![70 3][]

package com.dao;
    
    import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    
    public class BaseDao {
    	
    	private SessionFactory sessionFactory;
    	private Session session;
    	
    	public SessionFactory getSessionFactory() {
    		return sessionFactory;
    	}
    	public void setSessionFactory(SessionFactory sessionFactory) {
    		this.sessionFactory = sessionFactory;
    	}
    	public Session getSession(){
    		return sessionFactory.openSession();
    	}
    }

package com.dao;
    
    import java.util.List;
    
    import com.model.Studentsinfo;
    
    public interface InterPagingDao {
    	
    	public int findTotalRecordsDao();
    	
    	public List<Studentsinfo> findShowRecordsDao(int skipRecords,int pageSize);
    }

package com.dao;
    
    import java.util.List;
    
    import org.hibernate.Query;
    import org.hibernate.Session;
    import org.hibernate.Transaction;
    
    import com.model.Studentsinfo;
    
    public class PagingDaoImpl extends BaseDao implements InterPagingDao {
    
    	@Override
    	public int findTotalRecordsDao() {
    		
    		try{
    			Session session=getSession();	//继承中获取session
    			Transaction ts=session.beginTransaction();//开始事务
    			return session.createQuery("from Studentsinfo").list().size();//返回记录条数
    		}catch(Exception e){
    			e.printStackTrace();
    			return 0;
    		}
    	}
    
    	@Override
    	public List<Studentsinfo> findShowRecordsDao(int skipRecords, int pageSize) {
    		
    		Session session=getSession();
    		Transaction ts=session.beginTransaction();
    		Query query=session.createQuery("from Studentsinfo");
    		query.setFirstResult(skipRecords);//指定从哪一条记录开始查
    		query.setMaxResults(pageSize);	 //设置要查找的记录数
    		List<Studentsinfo> list=query.list();
    		ts.commit();
    		session.close();
    		return list;
    	}
    
    }

7、在action包下编写流程控制的action类

package com.action;
    
    import java.util.List;
    import java.util.Map;
    
    import com.model.Studentsinfo;
    import com.opensymphony.xwork2.ActionContext;
    import com.opensymphony.xwork2.ActionSupport;
    import com.service.InterPagingService;
    import com.tools.Paging;
    
    public class PagingAction extends ActionSupport{
    	
    	private int pageNow=1;	//初始化为当前页为1，通过请求可更改
    	private int pageSize=4; //每页显示数为4，同上
    	
    	private InterPagingService pagingServiceImpl;
    	
    	public String execute()throws Exception{
    		
    		pageNow=getPageNow();	//获取要设置的当前页值
    		pageSize=getPageSize(); //获取要设置的每页记录数
    		int totalRecords=pagingServiceImpl.findTotalRecords();//获取查找到的总记录数
    		
    		//判断用户可能输入的当前页是否超出范围,超出重置为1
    		if(pageNow<1 || pageNow>((pageSize+totalRecords-1)/pageSize))
    			pageNow=1;
    		
    		Map request=(Map)ActionContext.getContext().get("request");
    		Paging paging=new Paging(pageNow,pageSize,totalRecords);//获取分页对象
    
    		List<Studentsinfo> list=pagingServiceImpl.findShowRecords(pageNow, pageSize);
    		//System.out.println(list);
    		//System.out.println(paging);
    		request.put("list",list);
    		request.put("paging", paging);
    		return SUCCESS;
    	}
    	
    	public InterPagingService getPagingServiceImpl() {
    		return pagingServiceImpl;
    	}
    
    	public void setPagingServiceImpl(InterPagingService pagingServiceImpl) {
    		this.pagingServiceImpl = pagingServiceImpl;
    	}
    
    	public int getPageNow() {
    		return pageNow;
    	}
    
    	public void setPageNow(int pageNow) {
    		this.pageNow = pageNow;
    	}
    
    	public int getPageSize() {
    		return pageSize;
    	}
    
    	public void setPageSize(int pageSize) {
    		this.pageSize = pageSize;
    	}
    
    }

6、配置文件web.xml、struts.xml、applicationContext.ml

<?xml version="1.0" encoding="UTF-8"?>
    <web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
      
      <filter>
      	<filter-name>struts2</filter-name>
      	<filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class>
      </filter>
      <filter-mapping>
      	<filter-name>struts2</filter-name>
      	<url-pattern>/*</url-pattern>
      </filter-mapping>
      
      <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
      </listener>
      <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/classes/applicationContext.xml</param-value>
      </context-param>
    </web-app>

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE struts PUBLIC
            "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN"
            "http://struts.apache.org/dtds/struts-2.0.dtd">
    	<struts>
    		<package name="default" extends="struts-default">
    		
    			
    			<action name="paging" class="pagingAction">
    				<result name="success">/paging.jsp</result>
    			</action>
    			
    		</package>
    		
    	</struts>

<?xml version="1.0" encoding="UTF-8"?>
    <beans
    	xmlns="http://www.springframework.org/schema/beans"
    	xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    	xmlns:p="http://www.springframework.org/schema/p"
    	xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd" xmlns:tx="http://www.springframework.org/schema/tx">
    
    
    	<bean id="dataSource"
    		class="org.apache.commons.dbcp.BasicDataSource">
    		<property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
    		<property name="url" value="jdbc:mysql://localhost:3306/"></property>
    		<property name="username" value="root"></property>
    		<property name="password" value="root123"></property>
    	</bean>
    	<bean id="sessionFactory"
    		class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
    		<property name="dataSource">
    			<ref bean="dataSource" />
    		</property>
    		<property name="hibernateProperties">
    			<props>
    				<prop key="hibernate.dialect">
    					org.hibernate.dialect.MySQLDialect
    				</prop>
    			</props>
    		</property>
    		<property name="mappingResources">
    			<list>
    				<value>com/model/Studentsinfo.hbm.xml</value></list>
    		</property></bean>
    	<bean id="transactionManager"
    		class="org.springframework.orm.hibernate4.HibernateTransactionManager">
    		<property name="sessionFactory" ref="sessionFactory" />
    	</bean>
    	<tx:annotation-driven transaction-manager="transactionManager" />
    	
    	<bean id="baseDao" class="com.dao.BaseDao">
    		<property name="sessionFactory"><ref bean="sessionFactory"></ref></property>
    	</bean>
    	<bean id="pagingDaoImpl" class="com.dao.PagingDaoImpl" parent="baseDao"></bean>
    	<bean id="pagingServiceImpl" class="com.service.PagingServiceImpl">
    		<property name="pagingDaoImpl" ref="pagingDaoImpl"></property>
    	</bean>
    	<bean id="pagingAction" class="com.action.PagingAction">
    		<property name="pagingServiceImpl" ref="pagingServiceImpl"></property>
    	</bean>
    	<bean id="paging" class="com.tools.Paging"></bean>
    	
    	
    	</beans>

7、编写jsp页面输出

<%@ page language="java" import="java.util.*,com.tools.Paging" pageEncoding="utf-8"%>
    <%@ taglib prefix="s" uri="/struts-tags" %>
    <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
    <html>
      <head>   
        <title>ssh2 paging</title>
      </head>
      <script src=js/jquery-3.0.0.min.js></script>
    
     	<script type="text/javascript">
    			
    			function pageSizeChange(){			
    				var v_pageSize=$("#pageSizeButt").val()			
    				document.location.href="paging.action?pageSize="+v_pageSize+"&pageNow=1";
    			}
    			
    			$(function(){
    				<%
    				Paging pageInfo=(Paging)request.getAttribute("paging");
    				int vPageSize=3;
    				if(pageInfo!=null)
    					vPageSize=pageInfo.getPageSize();
    				%>
    				$("#pageSizeButt").val("<%=vPageSize%>")
    			})
    			
    	</script>
      <style>
    		table{
    			height: 100px;
    			margin: 80px auto;
    			margin-bottom:20px;
    			text-align: center;
    		}
    		caption{
    			margin: 30px;
    		}
    		thead th,td{
    			width:100px;
    		}
     		ul{
    			position: fixed;
    			left: 27%;
    			top: auto;			
    			text-decoration: none;
    		} 
    		li{
    			margin:5px;
    			list-style: none;
    			display: inline;
    		}
    		#goButt{
    			width:30px;
    		}
     		#dropPages{
    			width: 65px;
    			height: 23px; 
    		} 
    		a{text-decoration:none;}
    	</style>
      
      <body>
      	<s:form action="paging"  theme="simple">
      		<s:submit value="sumbit"/>
      	</s:form>
    	<table style="border-bottom:gainsboro solid 1px;border-top:gainsboro solid 1px;">
    			<caption>学生信息表</caption>
    			<thead>
    				<th>学号</th>
    				<th>姓名</th>
    				<th>籍贯</th>
    				<th>专业</th>
    				<th>电话</th>
    			</thead>
    			
    			<s:iterator value="#request.list" id="stu">
    		   	<tr>
    		   		<td><s:property value="#stu.sno" /></td>
    		   		<td><s:property value="#stu.name" /></td>
    		   		<td><s:property value="#stu.residence" /></td>
    		   		<td><s:property value="#stu.major" /></td>
    		   		<td><s:property value="#stu.phone" /></td>
    		   	</tr>
    	   		</s:iterator>
    
    		</table>
    		<s:form action="paging" method="post" theme="simple">
    		<ul>
    			<s:set name="page" value="#request.paging"/>
    			<li>
    				<s:if test="#page.hasFirst">
    					<s:a href="paging.action?pageNow=1">
    						<input type="button" value="首页" />
    					</s:a>
    				</s:if>
    			</li>
    			<li>
    				<s:if test="#page.hasPre">
    					<a href="paging.action?pageNow=<s:property value="#page.pageNow-1"/>">
    						<input type="button" value="上一页" />
    					</a>
    				</s:if>
    			</li>
    			<li>
    				共<s:property value="#page.pageNow"/>/<s:property value="#page.totalPages"/>页
    				  
    				转到<s:textfield name="pageNow" size="1"/>页 
    				<s:submit value="Go" id="goButt"/>
    			</li>
    			<li>每页
    				<select name="pageSize" onchange="pageSizeChange()" id="pageSizeButt">
    					<option value="3">3</option>
    					<option value="4">4</option>
    					<option value="5">5</option>
    					<option value="10">10</option>
    				</select>
    				条记录
    			</li>
    			<li>
    				<s:if test="#page.hasNext">
    					<a href="paging.action?pageNow=<s:property value="#page.pageNow+1"/>">
    						<input type="button" value="下一页" />
    					</a>
    				</s:if>
    			</li>
    			<li>
    				<s:if test="#page.hasLast">
    					<a href="paging.action?pageNow=<s:property value="#page.totalPages"/>">
    						<input type="button" value="尾页" />
    					</a>
    				</s:if>
    			</li>
    		</ul>
    		</s:form>   
      </body>
    </html>

8、测试结果

起初访问jsp页面没有数据，后台也没有报错。调试发现action类没有执行。原因是jsp没有发送请求，可通过修改添加空表单，点击提交链接到action完成初始化（后来才想到其实可以直接访问action完成初始化）。

实现的跳转页功能也用了表单action属性。

实现设置每页最大显示数用了select标签的onchange()函数功能，select显示的值稍微多绕了些才知道可以通过嵌入Java代码获取page对象拿到pageSize属性值，完成当前记录数的显示。

![70 4][]

跳转到第二页（其中Go是表单提交）

![70 5][]

点击尾页

![70 6][]

修改每页十条，当前页会设置为1

![70 7][]

如果想下载代码查看，[请戳这里][Link 1]

[70]: /images/20220518/022d7f069fab4e8e8e95146fa9303821.png
[70 1]: /images/20220518/431b09810382456e90a36de544c26cf3.png
[70 2]: /images/20220518/3e935eb2317142b8a1aa8f74d3a99463.png
[70 3]: /images/20220518/de3833003a7a40b4b03fdb208466f554.png
[70 4]: /images/20220518/03d26afe3dbb4e258b26473a65a87c91.png
[70 5]: /images/20220518/171f9be93fea4b518bcb717fea20571e.png
[70 6]: /images/20220518/1d5ed021250f4a8d919d6eadc9d6866e.png
[70 7]: /images/20220518/109935957cad4f6ba388a95b720813c4.png
[Link 1]: https://download.csdn.net/download/zero_130/10570745