mybatis分页插件使用案例

mybatis分页插件使用案例

• 基于ssm整合案例

1、导包

<dependency>
    <groupId>com.github.pagehelper</groupId>
    <artifactId>pagehelper</artifactId>
    <version>5.1.2</version>
</dependency>

2、在mybatis的全局配置文件中配置PageHelper分页插件

• applicationContext.xml配置文件中要指定mybatis全局配置文件的位置

<!-- 引入 pageHelper插件，注意这里要写成PageInterceptor, 5.0之前的版本都是写PageHelper, 5.0之后要换成PageInterceptor-->
<plugins>
    <plugin interceptor="com.github.pagehelper.PageInterceptor">
        <!--reasonable：分页合理化参数，默认值为false,直接根据参数进行查询。当该参数设置为 true 时，pageNum<=0 时会查询第一页， pageNum>pages（超过总数时），会查询最后一页。-->
        <property name="reasonable" value="true"/>
    </plugin>
</plugins>

3、持久层接口

package com.yl.dao;

import com.yl.bean.Book;
import com.yl.bean.PageBook;
import org.apache.ibatis.annotations.Param;

import java.util.List;

/**
 * 图书持久层接口
 */
public interface IBookDao {

    /**
     * 查询所有图书
     */
    List<Book> queryAll();

}

4、持久层映射文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.yl.dao.IBookDao">
    <!--配置实体类属性和数据库字段对应关系-->
    <resultMap id="bookMap" type="com.yl.bean.Book">
        <id property="id" column="book_id"></id>
        <result property="name" column="book_name"></result>
        <result property="author" column="book_author"></result>
        <result property="date" column="book_date"></result>
        <result property="price" column="book_price"></result>
    </resultMap>

    <!--查询所有图书，写普通的查询即可，插件会自动分页-->
    <select id="queryAll" resultMap="bookMap">
        select * from tb_book
    </select>

</mapper>

5、业务层接口

package com.yl.service;

import com.github.pagehelper.PageInfo;
import com.yl.bean.Book;
import com.yl.bean.PageBook;

import java.util.List;

/**
 * 图书业务层接口
 */
public interface IBookService {

    /**
     * 查询所有图书
     */
    PageInfo<Book> queryAll(int pageCode, int pageSize);

}

6、业务层接口实现类

package com.yl.service.impl;

import com.github.pagehelper.PageHelper;
import com.github.pagehelper.PageInfo;
import com.yl.bean.Book;
import com.yl.bean.PageBook;
import com.yl.dao.IBookDao;
import com.yl.service.IBookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;

import java.util.List;

/**
 * 图书业务层接口实现类
 */
@Service("bookService")
public class IBookServiceImpl implements IBookService {
    @Autowired
    private IBookDao bookDao;

    /**
     * 查询所有图书
     * @param pageCode
     * @param pageSize
     * @return
     */
    @Override
    public PageInfo<Book> queryAll(int pageCode, int pageSize) {
        //分页查询
        PageHelper.startPage(pageCode,pageSize);//写在所有查询之前
        List<Book> bookList=bookDao.queryAll();
        PageInfo<Book> pageInfo = new PageInfo<Book>(bookList);

        return pageInfo;
    }
}

7、控制器

package com.yl.controller;

import com.github.pagehelper.PageInfo;
import com.yl.bean.Book;
import com.yl.bean.PageBook;
import com.yl.service.IBookService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.SessionAttributes;
import org.springframework.web.servlet.ModelAndView;

import java.util.List;

/**
 * 图书控制器类
 */
@Controller
@RequestMapping("/book")
@SessionAttributes(value = {"pageBook"},types ={PageBook.class} )
public class BookController {
    @Autowired
    private IBookService bookService;//图书业务层对象
  
    /**
     * 查询所有图书
     */
    @RequestMapping("/queryAll")
    public ModelAndView queryAll(int pageCode){
        int pc=1;//页码,默认为第一页
        int pageSize=3;//页面数据条数

        //判断表单页码是否为空
        if (pageCode>0){
            pc=pageCode;
        }

        //调用业务层查询所有方法
        PageInfo<Book> pageInfo=bookService.queryAll(pc,pageSize);

        ModelAndView modelAndView=new ModelAndView();
        modelAndView.addObject("pageBook",pageInfo);
        modelAndView.setViewName("index");

        return modelAndView;
    }

}

8、jsp

<form method="post" action="${pageContext.servletContext.contextPath}/book/queryByPage">
    <table>
        <tr>
            <th>书名</th>
            <th>作者</th>
            <th>出版日期</th>
            <th>价格</th>
        </tr>
        <c:forEach items="${sessionScope.pageBook.list}" var="book">
            <tr>
                <td>${book.name}</td>
                <td>${book.author}</td>
                <td>${book.date}</td>
                <td>${book.price}</td>
            </tr>
        </c:forEach>
    </table>
    第${sessionScope.pageBook.pageNum}页/共${sessionScope.pageBook.pages}页
    <a href="<c:url value="/book/queryAll?pageCode=1"/>">首页</a>
    <c:if test="${sessionScope.pageBook.pageNum>1}">
        <a href="<c:url value="/book/queryAll?pageCode=${sessionScope.pageBook.pageNum-1}"/>">上一页</a>
    </c:if>
    <c:if test="${sessionScope.pageBook.pageNum<sessionScope.pageBook.pages}">
        <a href="<c:url value="/book/queryAll?pageCode=${sessionScope.pageBook.pageNum+1}"/>">下一页</a>
    </c:if>
    <a href="<c:url value="/book/queryAll?pageCode=${sessionScope.pageBook.pages}"/>">尾页</a>
</form>