PageInfo的介绍与使用

转载：https://blog.csdn.net/sinat_42338962/article/details/84314428

https://blog.csdn.net/zhijun0901/article/details/88084357

 

1.PageInfo属性表

当前页 
private int pageNum;
每页的数量  
private int pageSize;  
当前页的数量  
private int size;  
//由于startRow和endRow不常用，这里说个具体的用法  
//可以在页面中"显示startRow到endRow 共size条数据"  

当前页面第一个元素在数据库中的行号  
private int startRow;  
当前页面最后一个元素在数据库中的行号  
private int endRow;  
总记录数  
private long total;  
总页数  
private int pages;  
结果集  
private List<T> list;  

第一页  
private int firstPage;  
前一页  
private int prePage;  

是否为第一页  
private boolean isFirstPage = false;  
是否为最后一页  
private boolean isLastPage = false;  
是否有前一页  
private boolean hasPreviousPage = false;  
是否有下一页  
private boolean hasNextPage = false;  
导航页码数  
private int navigatePages;  
所有导航页号  
private int[] navigatepageNums;  
后台分页

服务器端
service
public PageInfo<T>  methodName(int pageNum, int pageSize) {
//1 设置分页
        PageHelper.startPage(pageNum, pageSize);
        //2 查询
        List<T> list =TMapper.mapperMethod();
        //3 返回
        return new PageInfo<>(list);
    }
Web
public @ResponseBody DataGridResultInfo methodName (Vovo){
        //1 查询
        PageInfo<T> pageInfo = service. methodName (vo.getPage(), vo.getRows());
        //2 封装
        return new DataGridBean(pageInfo.getTotal() , pageInfo.getList() );
    }

浏览器端
Datagrid

$(function(){
        //绘制datagrid
        //1 准备数据
        // 1.1 列列表
        var columnArr = [[
                          {field:'字段名1',title:'标题1',80}, 
                          {field:'字段名2',title:'标题2',80,
                              formatter:function(value,rows,index){
                                //filed匹配值(当前的值),当前行,当前行号
                                  return value.info;
                              }
                          }
                          ]];
        // 1.2 工具条
        var toolbarArr = [
                            {
                                iconCls: 'icon-add',//按钮图标
                                text : '添加用户',
                                handler: showadduser//方法名
                            }
                          ];
        // 1.3 请求路径
        var url = "……";
        
        //2 准备参数
        var options = {
            "columns":columnArr,
            "toolbar":toolbarArr,
            "striped":true,                //隔行换色
            "idField":"id",                //标识字段
            "url":url,                    //请求路径
            "pagination":true,
            "rownumbers":true,
            "pageSize":2,
            "pageList":[2,4,6,8]
        };
        
        //3 绘制
        $("#id值").datagrid( options );
        
    });

感觉这个很简单,没什么好写的
不用工具
<c:forEach items="${pageInfo.list}" var="p">
      <tr>
          <td>${p.属性1}</td>
<td>${p.属性2}</td>
<td>${p.属性…}</td>
</tr>
</c:forEach>

2.PageInfo类的使用——Java Page分页显示

//entity层实体类
 
import java.util.List;
 
//分页展示
//相关属性：当前页，页大小(每页显示的条数)，总页数，总条数，数据
//select * from t_user limit 3,3
public class Page {
    private Integer currentPage;  //当前页
    private Integer pageSize;     //页大小
    private Integer pageCount;   //页数量
    private Integer totalCount;  //总条数
    private List<?> list;        //数据
    private String  url;         //参数路径
    public Integer getCurrentPage() {
        return currentPage;
    }
    public void setCurrentPage(Integer currentPage) {
        this.currentPage = currentPage;
    }
    public Integer getPageSize() {
        return pageSize;
    }
    public void setPageSize(Integer pageSize) {
        this.pageSize = pageSize;
    }
    public Integer getPageCount() {
        return pageCount;
    }
    public void setPageCount(Integer pageCount) {
        this.pageCount = pageCount;
    }
    public Integer getTotalCount() {
        return totalCount;
    }
    public void setTotalCount(Integer totalCount) {
        this.totalCount = totalCount;
    }
    public List<?> getList() {
        return list;
    }
    public void setList(List<?> list) {
        this.list = list;
    }
    public String getUrl() {
        return url;
    }
    public void setUrl(String url) {
        this.url = url;
    }
    
    @Override
    public String toString() {
        return "Page [currentPage=" + currentPage + ", pageSize=" + pageSize + ", pageCount=" + pageCount
                + ", totalCount=" + totalCount + ", list=" + list + ", url=" + url + "]";
    }
    
    public Page(Integer currentPage, Integer pageSize, Integer pageCount, Integer totalCount, List<?> list,
            String url) {
        this.currentPage = currentPage;
        this.pageSize = pageSize;
        this.pageCount = pageCount;
        this.totalCount = totalCount;
        this.list = list;
        this.url = url;
    }
    
    public Page() {
    }
    
    public Page(Integer currentPage, Integer pageSize) {
        this.currentPage = currentPage;
        this.pageSize = pageSize;
    }
}

// servlet层 （分页相关代码）
//-----直接做分页展示-----
String current = request.getParameter("currentPage"); // 获取前端传入的当前页
Page page = goodsInfoService.getPage(current); // 在业务层给page对象赋值
request.setAttribute("page", page);

//service层相关代码
public Page getPage(String current) {
    Integer currentPage = 1; // 默认为第一页
    Integer pageSize    = 5; // 每页显示5条记录
    if(current != null){
        currentPage = Integer.parseInt(current);
    }
    Page page = new Page(currentPage, pageSize);  //当前页和页大小的赋值
    
    Integer totalCount = goodsInfoDao.getTotalCount();
    page.setTotalCount(totalCount);  //设置总条数
    
　　 // 页数量==总条数/页大小--如果整除就是该值，否则+1
    Integer pageCount = totalCount/pageSize;
    pageCount=totalCount%pageSize==0?pageCount:pageCount+1;
    page.setPageCount(pageCount);   //设置页数量
    
    Integer startIndex = (currentPage-1)*pageSize; // 起始下标为（当前页-1）*页大小
    List<GoodsInfo> list = goodsInfoDao.getGoodsInfoListPage(startIndex, pageSize);
    page.setList(list);   //设置数据
    
    page.setUrl("GoodsInfoServlet?action=goodsInfoList");  //设置url
    
    return page;
}

//Dao相关分页代码
public int getTotalCount() { // 获取总记录数
    String sql="select count(1) from t_goods_info";
    return CommonUtils.getTotalCount(sql);
}

//jquery 相关分页代码
<a href="${page.url}&currentPage=1">首页</a>
    <c:if test="${page.currentPage!=1}">
        <a href="${page.url}&currentPage=${page.currentPage-1}">上一页</a>
    </c:if>
    <c:if test="${page.currentPage!=page.pageCount}">
        <a href="${page.url}&currentPage=${page.currentPage+1}">下一页</a>
    </c:if>
    <a href="${page.url}&currentPage=${page.pageCount}">尾页</a>
共${page.currentPage}/${page.pageCount}页

3.MyBatis分页插件－PageHelper的配置与应用

以下转载于：https://www.cnblogs.com/li150dan/p/9706585.html

下载地址：https://github.com/pagehelper/Mybatis-PageHelper

Pagehelper 下载地址：

http://repo1.maven.org/maven2/com/github/pagehelper/pagehelper/

jsqlparser 下载地址：

http://repo1.maven.org/maven2/com/github/jsqlparser/jsqlparser/

使用步骤：

pom.xml 引入依赖:

<!-- pagehelper :分页插件 -->
<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper</artifactId>
    <version>5.1.2</version>
</dependency>
<!-- pagehelper的依赖包:jsqlparser -->
<dependency>
    <groupId>com.github.jsqlparser</groupId>
    <artifactId>jsqlparser</artifactId>
    <version>0.9.5</version>
</dependency>

1、导入相关包 pagehelper-x.x.x.jar 和 jsqlparser-x.x.x.jar。

2、在MyBatis全局配置文件中配置分页插件。 

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
 
<!-- 注意 <plugins> 在xml文件中的位置，必须要符合 http://mybatis.org/dtd/mybatis-3-config.dtd 中指定的顺序：-->
<!-- configuration (properties?, settings?, typeAliases?, typeHandlers?,
    objectFactory?, objectWrapperFactory?, plugins?, environments?, databaseIdProvider?, mappers?) -->
<configuration>    
    <!-- 为SQL定义部分的parameterType或resultType属性指定自定义类型的别名 -->
    <typeAliases>        
        <typeAlias alias="ServiceStation" type="com.mybatis.models.ServiceStation" />
        <typeAlias alias="InspectorInfo" type="com.mybatis.models.InspectorInfo" />
        <typeAlias alias="StationInspector" type="com.mybatis.models.StationInspector" />
    </typeAliases>
    <!-- 配置分页拦截器 -->
    <plugins>
        <!-- 配置分页插件  -->
        <plugin interceptor="com.github.pagehelper.PageInterceptor"></plugin>
        <!-- com.mybatis.util为PageHelper类所在包名 -->
        <!-- <plugin interceptor="com.mybatis.util.PagePlugin"> -->
            <!-- 设置数据库类型 Oracle,Mysql,MariaDB,SQLite,Hsqldb,PostgreSQL六种数据库-->       
            <!-- <property name="dialect" value="SQLite" /> -->
            <!-- <property name="pageSqlId" value=".*Page.*" /> -->
        <!-- </plugin> -->
    </plugins>  
    <!-- 设置数据库连接参数 -->
    <!-- 与spring 集成之后,这些可以完全删除,数据库连接的管理交给 spring 去管理 -->
    <environments default="development">
        <environment id="development">
        <transactionManager type="JDBC" />
            <dataSource type="POOLED"> 
                <property name="driver" value="com.microsoft.sqlserver.jdbc.SQLServerDriver" />
                <property name="url" value="jdbc:sqlserver://mssql-rw-cyp-coopbusiness.vip.test.suixinhuan.com;DatabaseName=CYP_CoopBusiness" />
                <property name="username" value="Umanager" />
                <property name="password" value="ASD123asd!1" />
           </dataSource>
        </environment>
    </environments>  
    <!-- 加载SQL定义文件 -->
    <!-- 这里交给sqlSessionFactory 的 mapperLocations属性去得到所有配置信息 -->
    <mappers>          
         <mapper resource="com/mybatis/sql/ServiceStation.xml" />
         <mapper resource="com/mybatis/sql/InspectorInfo.xml" />
         <mapper resource="com/mybatis/sql/StationInspector.xml" />
    </mappers>
</configuration>

3、使用PageHelper提供的方法进行分页

package com.mybatis;
 
import java.util.List;
 
import org.apache.ibatis.session.SqlSession;
 
import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.mybatis.dao.InspectorInfoMapper;
import com.mybatis.dao.MyBatisUtil;
import com.mybatis.dao.ServiceStationMapper;
import com.mybatis.dao.StationInspectorMapper;
import com.mybatis.models.ServiceStation;
import com.mybatis.models.InspectorInfo;
import com.mybatis.models.StationInspector;
//import com.mybatis.util.Page;
 
/*
 * 测试类
 */
public class HelloMyBatisProgram {
     public static void main(String[] args) {
          SqlSession session = MyBatisUtil.getSession();
          //由框架生成ServiceStationMapper接口实现对象
          ServiceStationMapper ssDaoMaper = session.getMapper(ServiceStationMapper.class);
          InspectorInfoMapper iiDaoMaper = session.getMapper(InspectorInfoMapper.class);
          StationInspectorMapper siDaoMaper = session.getMapper(StationInspectorMapper.class);
          //System.out.println(ssDaoMaper.getClass().getName());       
          System.out.println("===========分页获取所有服务站列表============");    
        
          //分页设置放在查询之前           
          Page<Object> page = PageHelper.startPage(1, 5, "StationName");
          List<ServiceStation> listPage = ssDaoMaper.findAllPage("110100");      
          for(ServiceStation item:listPage) {
              System.out.println(item.getStationName()+"  "+item.getCityCode()+"  "+item.getCityName());
          }    
          System.out.println("当前页码："+page.getPageNum());
          System.out.println("每页的记录数："+page.getPageSize());
          System.out.println("总记录数："+page.getTotal());
          System.out.println("总页码："+page.getPages());              
     }    
}

 4、可以使用更强大的PageInfo封装返回结果

package com.mybatis;
 
import java.util.List;
 
import org.apache.ibatis.session.SqlSession;
 
import com.github.pagehelper.Page;
import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.mybatis.dao.InspectorInfoMapper;
import com.mybatis.dao.MyBatisUtil;
import com.mybatis.dao.ServiceStationMapper;
import com.mybatis.dao.StationInspectorMapper;
import com.mybatis.models.ServiceStation;
import com.mybatis.models.InspectorInfo;
import com.mybatis.models.StationInspector;
//import com.mybatis.util.Page;
 
/*
 * 测试类
 */
public class HelloMyBatisProgram {
     public static void main(String[] args) {
          SqlSession session = MyBatisUtil.getSession();
          //由框架生成ServiceStationMapper接口实现对象
          ServiceStationMapper ssDaoMaper = session.getMapper(ServiceStationMapper.class);
          InspectorInfoMapper iiDaoMaper = session.getMapper(InspectorInfoMapper.class);
          StationInspectorMapper siDaoMaper = session.getMapper(StationInspectorMapper.class);
          //System.out.println(ssDaoMaper.getClass().getName());       
          System.out.println("===========分页获取所有服务站列表============");    
             
          //分页设置放在查询之前           
          page = PageHelper.startPage(1, 3, "StationName desc");
          List<ServiceStation> list = ssDaoMaper.findAll();
          for(ServiceStation item:list) {
               System.out.println(item.getStationName()+"  "+item.getCityCode()+"  "+item.getCityName());
          }         
          PageInfo<ServiceStation> info = new PageInfo<ServiceStation>(list, 3);                   
          System.out.println("当前页码："+info.getPageNum());
          System.out.println("每页的记录数："+info.getPageSize());
          System.out.println("总记录数："+info.getTotal());
          System.out.println("总页码："+info.getPages());
          System.out.println("是否第一页："+info.isIsFirstPage());
          System.out.println("连续显示的页码：");
          int[] nums = info.getNavigatepageNums();
          for (int i = 0; i < nums.length; i++) {
               System.out.println(nums[i]);
          }      
     }    
}