在SSH项目中实现分页效果

在实现分页的时候，我使用的是数据库下面的User表，实现的效果是通过分页查询

能够将表中的数据分页显示，点击相关的按钮实现：首页、上一页、下一页、末页的显示

1新建一个dynamic web project项目 ，导入SSH项目所需要的jar

antlr-2.7.7.jar
c3p0-0.9.5.2.jar
classmate-1.3.0.jar
com.springsource.org.aopalliance-1.0.0.jar
com.springsource.org.apache.commons.dbcp-1.2.2.osgi.jar
com.springsource.org.apache.commons.logging-1.1.1.jar
com.springsource.org.apache.commons.pool-1.5.3.jar
com.springsource.org.aspectj.weaver-1.6.8.RELEASE.jar
commons-fileupload-1.3.2.jar
commons-io-2.4.jar
commons-lang3-3.4.jar
dom4j-1.6.1.jar
freemarker-2.3.23.jar
hibernate-c3p0-5.2.10.Final.jar
hibernate-commons-annotations-5.0.1.Final.jar
hibernate-core-5.2.10.Final.jar
hibernate-jpa-2.1-api-1.0.0.Final.jar
jandex-2.0.3.Final.jar
javassist-3.20.0-GA.jar
jboss-logging-3.3.0.Final.jar
jboss-transaction-api_1.2_spec-1.0.1.Final.jar
jstl.jar
log4j-api-2.7.jar
mchange-commons-java-0.2.11.jar
mysql-connector-java-5.1.24-bin.jar
mysql-connector-java-5.1.7-bin.jar
ognl-3.1.12.jar
spring-aop-4.3.6.RELEASE.jar
spring-aspects-4.3.6.RELEASE.jar
spring-beans-4.3.6.RELEASE.jar
spring-context-4.3.6.RELEASE.jar
spring-core-4.3.6.RELEASE.jar
spring-expression-4.3.6.RELEASE.jar
spring-jdbc-4.3.6.RELEASE.jar
spring-orm-4.3.6.RELEASE.jar
spring-tx-4.3.6.RELEASE.jar
spring-web-4.3.6.RELEASE.jar
standard.jar
struts2-core-2.5.10.1.jar
struts2-spring-plugin-2.5.10.1.jar

2 在web.xml下配置Struts的过滤器<context-param>和<listener>

<?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">
  <display-name>PagePractice</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>

  <filter>
  <filter-name>Struts2</filter-name>
  <filter-class>org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter</filter-class>
  </filter>
  <filter-mapping>
  <filter-name>Struts2</filter-name>
  <url-pattern>/*</url-pattern>
  </filter-mapping>

  <context-param>
     <param-name>contextConfigLocation</param-name>
     <param-value>classpath:applicationContext.xml</param-value>
  </context-param>
 <listener>
      <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
 </listener>
</web-app>

3 按照SSH项目的套路，建立相关的类。其中特殊点在于工具类和dao的实现类

工具类代码如下：

package com.whl.utils;

import com.whl.bean.Page;

public class PageUtils {

    public static Page getPage(int everyPage, int totalCount, int currentPage) {
        Page page = null;
        everyPage = getEveryPage(everyPage);
        currentPage = getCurrentPage(currentPage);
        int totalPage = getTotalPage(everyPage, totalCount);
        int beginIndex = getBeginIndex(everyPage, currentPage);
        boolean hasPrePage = hasPrePage(currentPage);
        boolean hasNextPage = hasNextPage(totalPage, currentPage);
        return page = new Page(everyPage, totalCount, totalPage, currentPage, beginIndex, hasPrePage, hasNextPage);
    }

    /**
     * 设定每一页显示的记录数
     *
     * @param everyPage
     * @return
     */
    public static int getEveryPage(int everyPage) {
        return everyPage == 0 ? 3 : everyPage;
    }

    /**
     * 设定当前页
     *
     * @param currentPage
     * @return
     */
    public static int getCurrentPage(int currentPage) {
        return currentPage == 0 ? 1 : currentPage;
    }

    /**
     * 设定分页的总页数
     *
     * @param everyPage
     * @param totalCount
     * @return
     */
    public static int getTotalPage(int everyPage, int totalCount) {
        int num = totalCount / getEveryPage(everyPage);
        return totalCount % getEveryPage(everyPage) == 0 ? num : num + 1;
    }

    /**
     * 设置起始点
     *
     * @param everyPage
     * @param currentPage
     * @return
     */
    public static int getBeginIndex(int everyPage, int currentPage) {
        return (getCurrentPage(currentPage) - 1) * getEveryPage(everyPage);
    }

    /**
     * 设置是否有上一页
     *
     * @param currentPage
     * @return
     */
    public static boolean hasPrePage(int currentPage) {
        return getCurrentPage(currentPage) == 1 ? false : true;
    }

    /**
     * 设置是否有下一页
     *
     * @param currentPage
     * @return
     */
    public static boolean hasNextPage(int totalPage, int currentPage) {
        return getCurrentPage(currentPage) == totalPage || totalPage == 0 ? false : true;
    }
}

dao的实现类如下：

package com.whl.daoimpl;

import java.util.List;

import org.hibernate.Session;
import org.springframework.orm.hibernate5.HibernateTemplate;

import com.whl.bean.Page;
import com.whl.bean.User;
import com.whl.dao.IUserDao;
import com.whl.utils.PageUtils;

public class IUserDaoImpl extends HibernateTemplate implements IUserDao {

    @Override
    public List<User> getUserByPage(int currentPage) {
        List<User> list = null;

        Session session=getSessionFactory().openSession();

        org.hibernate.query.Query<User> query = session.createQuery("select u from User u",User.class);

        //list=query.getResultList();

        int tote=query.list().size();
        System.out.println(tote+"kk");
        Page page=PageUtils.getPage(2, tote, currentPage);

        query.setMaxResults(page.getEveryPage());
        query.setFirstResult(page.getBeginIndex());

        list = query.getResultList();
        System.out.println("DDDD"+list);
        return list;
    }

    @Override
    public List<User> getAllUser() {
        List<User> list=getSessionFactory().openSession().createCriteria(User.class).list();
        return list;
    }

}

展示页面代码如下：

<%@page import="com.whl.bean.User"%>
<%@page import="java.util.List"%>
<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>User page</title>
<link href="css/stylesheet.css" rel="stylesheet" type="text/css" />
<link href="css/style.css" rel="stylesheet" type="text/css" />
<script type="text/javascript" src="js/jquery-1.3.2.min.js"></script>
<script type="text/javascript" src="js/simpla.jquery.configuration.js"></script>
<script type="text/javascript" src="js/javascript.js"></script>
<script type="text/javascript" src="datepicker/WdatePicker.js"> </script>
</head>

<body>
<div style="padding:5px;">
  <div class="txt" style="padding-top:3px;" >当前位置：统计报表&nbsp;&gt;&nbsp;客户构成分析
    <hr class="hr1" />
  </div>
  <div class="operation_button"> <a href="#" title="查询">查询</a> </div>
  <div class="search_input">
    <ul class="txt">
      <li>报表方式：
        <select>
          <option>按等级</option>
          <option>按信用度</option>
          <option>按满意度</option>
        </select>
      </li>
    </ul>
  </div>
  <div>
    <table width="100%" border="0" cellpadding="0" cellspacing="0" class="table_list" >
      <thead>
        <tr>
          <th width="15%">编号</th>
          <th width="65%">姓名</th>
          <th width="20%">密码</th>
        </tr>
      </thead>
      <%
       List<User> list=(List<User>)request.getAttribute("list");
       int tote=(Integer)request.getAttribute("tote");
       int p=(Integer)request.getAttribute("page");
       int totePage=(Integer)request.getAttribute("totalPage");
       if(p<=0){
           p=1;
       }if(p>=totePage){
           p=totePage-1;
       }
       for(int i=0;i<list.size();i++){
         User u=list.get(i);
      %>
      <tbody>
        <tr>
          <td><%=u.getId() %></td>
          <td><%=u.getUsername() %></td>
          <td><%=u.getUserpass() %></td>
        </tr>
      </tbody>
      <%
       }
      %>
    </table>
  </div>
  <div class="position"> 共<%=tote %>条记录&nbsp;每页2条&nbsp;
  <a href="getUser?page=<%=1 %>" title="首页">&laquo;首页</a>
   <a href="getUser?page=<%=p-1 %> " title="上一页">&laquo; 上一页</a>
   <a href="getUser?page=<%=p+1 %>" title="下一页">下一页&raquo;</a>
   <a href="getUser?page=<%=totePage %>" title="末页">末页&raquo;</a>
  </div>
</div>
</body>
</html>

Struts.xml代码：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE struts PUBLIC
    "-//Apache Software Foundation//DTD Struts Configuration 2.5//EN"
    "http://struts.apache.org/dtds/struts-2.5.dtd">
 <struts>
    <constant name="struts.devMode" value="false" />

    <package name="myStruts" extends="struts-default" namespace="/">

        <action name="getUser" class="getUser" method="getUser">
            <result>/list.jsp</result>
            <result name="input">/index.jsp</result>
        </action>

    </package>
 </struts>

applicationContext.xml代码

<?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:context="http://www.springframework.org/schema/context"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xsi:schemaLocation="http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/aop
        http://www.springframework.org/schema/aop/spring-aop.xsd">

       <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
        <property name="driverClass" value="com.mysql.jdbc.Driver"></property>
        <property name="jdbcUrl" value="jdbc:mysql://localhost:3306/test"></property>
        <property name="user" value="root"></property>
        <property name="password" value="123456"></property>
          <!--连接池中保留的最小连接数。-->
        <property name="minPoolSize" value="10" />
        <!--连接池中保留的最大连接数。Default: 15 -->
        <property name="maxPoolSize" value="100" />
        <!--最大空闲时间,1800秒内未使用则连接被丢弃。若为0则永不丢弃。Default: 0 -->
        <property name="maxIdleTime" value="1800" />
        <!--当连接池中的连接耗尽的时候c3p0一次同时获取的连接数。Default: 3 -->
        <property name="acquireIncrement" value="3" />
        <property name="maxStatements" value="1000" />
        <property name="initialPoolSize" value="10" />
        <!--每60秒检查所有连接池中的空闲连接。Default: 0 -->
        <property name="idleConnectionTestPeriod" value="60" />
        <!--定义在从数据库获取新连接失败后重复尝试的次数。Default: 30 -->
        <property name="acquireRetryAttempts" value="30" />
        <property name="breakAfterAcquireFailure" value="true" />
        <property name="testConnectionOnCheckout" value="false" />
    </bean>

    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate5.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">
                    org.hibernate.dialect.MySQL5InnoDBDialect
                </prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
            </props>
        </property>
        <property name="packagesToScan">
            <list>
                <value>com.whl.bean</value>
            </list>
        </property>
    </bean>

    <bean id="userDao" class="com.whl.daoimpl.IUserDaoImpl">
        <property name="sessionFactory" ref="sessionFactory"></property>
    </bean>
    <bean id="userService" class="com.whl.serviceimpl.IUserServiceImpl">
        <property name="userDao" ref="userDao"></property>
    </bean>
    <bean id="getUser" class="com.whl.action.UserAction">
        <property name="userService" ref="userService"></property>
    </bean>

</beans>
        

bean包下面的User类和Page类代码：

package com.whl.bean;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table
public class User {
    @Id
    @GeneratedValue(strategy=GenerationType.IDENTITY)
    private int id;
    @Column(length=30)
    private String username;
    @Column(length=30)
    private String userpass;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUsername() {
        return username;
    }
    public void setUsername(String username) {
        this.username = username;
    }
    public String getUserpass() {
        return userpass;
    }
    public void setUserpass(String userpass) {
        this.userpass = userpass;
    }
    public User(int id, String username, String userpass) {
        super();
        this.id = id;
        this.username = username;
        this.userpass = userpass;
    }
    public User() {
        super();
    }
    @Override
    public String toString() {
        return "User [id=" + id + ", username=" + username + ", userpass=" + userpass + "]";
    }

}

package com.whl.bean;

public class Page {

    //    1.    每页显示的数量
    private int everyPage;

    //    2.    总条目数
    private int totalCount;

    //    3.    总页数
    private int totalPage;

    //    4.    当前页数
    private int currentPage;

    //    5.    起始页
    private int beginIndex;

    //    6.    是否有上一页
    private    boolean hasPrePage;

    //    7.    是否还有下一页
    private boolean hasNextPage;

    public Page() {
    }

    public Page(int everyPage, int totalCount, int totalPage, int currentPage, int beginIndex, boolean hasPrePage,
            boolean hasNextPage) {
        super();
        this.everyPage = everyPage;
        this.totalCount = totalCount;
        this.totalPage = totalPage;
        this.currentPage = currentPage;
        this.beginIndex = beginIndex;
        this.hasPrePage = hasPrePage;
        this.hasNextPage = hasNextPage;
    }

    public int getEveryPage() {
        return everyPage;
    }

    public void setEveryPage(int everyPage) {
        this.everyPage = everyPage;
    }

    public int getTotalCount() {
        return totalCount;
    }

    public void setTotalCount(int totalCount) {
        this.totalCount = totalCount;
    }

    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 getBeginIndex() {
        return beginIndex;
    }

    public void setBeginIndex(int beginIndex) {
        this.beginIndex = beginIndex;
    }

    public boolean isHasPrePage() {
        return hasPrePage;
    }

    public void setHasPrePage(boolean hasPrePage) {
        this.hasPrePage = hasPrePage;
    }

    public boolean isHasNextPage() {
        return hasNextPage;
    }

    public void setHasNextPage(boolean hasNextPage) {
        this.hasNextPage = hasNextPage;
    }
}

action的代码：

package com.whl.action;

import java.util.List;

import javax.servlet.http.HttpServletRequest;

import org.apache.struts2.ServletActionContext;

import com.opensymphony.xwork2.ActionSupport;
import com.opensymphony.xwork2.ModelDriven;
import com.whl.bean.User;
import com.whl.service.IUserService;
import com.whl.utils.PageUtils;

public class UserAction extends ActionSupport implements ModelDriven<User>{
    private User user=new User();
    private IUserService userService;

    public void setUserService(IUserService userService) {
        this.userService = userService;
    }

    @Override
    public User getModel() {
        return user;
    }

    public String getUser(){
        HttpServletRequest request=ServletActionContext.getRequest();
        List<User> allUser = userService.getAllUser();
        int tote=allUser.size();
        int totalPage = PageUtils.getTotalPage(2, tote);
        System.out.println(request.getParameter("page"));
        int page=Integer.parseInt(request.getParameter("page"));
        List<User> list = userService.getUserByPage(page);
        if (list!=null&&list.size()!=0) {
            request.setAttribute("totalPage", totalPage);
            request.setAttribute("page", page);
            request.setAttribute("tote", tote);
            request.setAttribute("list", list);
            System.out.println(list);
            return SUCCESS;
        }
        return INPUT;

    }  

}

涉及到相关知识：

c3po的配置：

Spring的依赖注入;

注解实现Hibernate的映射