在 mybatis 中，使用 RowBounds 进行分页，非常方便，不需要在 sql 语句中写 limit，即可完成分页功能。但是由于它是在 sql 查询出所有结果的基础上截取数据的，所以在数据量大的sql中并不适用，它更适合在返回数据结果较少的查询中使用
最核心的是在 mapper 接口层，传参时传入 RowBounds(int offset, int limit) 对象，即可完成分页
注意：由于 java 允许的最大整数为 2147483647，所以 limit 能使用的最大整数也是 2147483647，一次性取出大量数据可能引起内存溢出，所以在大数据查询场合慎重使用
mapper 接口层代码如下
List<Book> selectBookByName(Map<String, Object> map, RowBounds rowBounds);调用如下
List<Book> list = bookMapper.selectBookByName(map, new RowBounds(0, 5));说明: new RowBounds(0, 5)，即第一页，每页取5条数据
测试示例
数据库数据
mapper 接口层
package com.demo.mapper;import java.util.List;
import java.util.Map;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.session.RowBounds;
import com.demo.bean.Book;@Mapper
public interface BookMapper {//添加数据int insert(Book book); //模糊查询List<Book> selectBookByName(Map<String, Object> map, RowBounds rowBounds);}
mapper.xml 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.demo.mapper.BookMapper"><resultMap id="BaseResultMap" type="com.demo.bean.Book"><id column="id" property="id" jdbcType="VARCHAR" /><result column="book_name" property="bookName" jdbcType="VARCHAR" /><result column="book_author" property="bookAuthor" jdbcType="VARCHAR" /><result column="create_date" property="createDate" jdbcType="VARCHAR" /><result column="update_date" property="updateDate" jdbcType="VARCHAR" /></resultMap><sql id="Base_Column_List">book_name as bookName, book_author as bookAuthor,create_date as createDate, update_date as updateDate</sql><insert id="insert" useGeneratedKeys="true" keyProperty="id" parameterType="com.demo.bean.Book">insert into book(book_name, book_author, create_date, update_date) values(#{bookName}, #{bookAuthor}, #{createDate}, #{updateDate}) </insert><select id="selectBookByName" resultMap="BaseResultMap"><bind name="pattern_bookName" value="'%' + bookName + '%'" /><bind name="pattern_bookAuthor" value="'%' + bookAuthor + '%'" />select * from book where 1 = 1<if test="bookName != null and bookName !=''">and book_name LIKE #{pattern_bookName}</if><if test="bookAuthor != null and bookAuthor !=''">and book_author LIKE #{pattern_bookAuthor}</if></select></mapper>测试代码
package com.demo;import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import org.apache.ibatis.session.RowBounds;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;
import com.demo.bean.Book;
import com.demo.mapper.BookMapper;@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringbootJspApplicationTests {@Autowiredprivate BookMapper bookMapper; @Testpublic void contextLoads() {Book book = new Book();book.setBookName("隋唐演义");book.setBookAuthor("褚人获");SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");book.setCreateDate(sdf.format(new Date()));book.setUpdateDate(sdf.format(new Date()));bookMapper.insert(book);System.out.println("返回的主键: "+book.getId());}@Testpublic void query() {Map<String, Object> map = new HashMap<String, Object>();map.put("bookName", "");map.put("bookAuthor", "");List<Book> list = bookMapper.selectBookByName(map, new RowBounds(0, 5));for(Book b : list) {System.out.println(b.getBookName());}}}
运行 query 查询第一页，5 条数据，效果如下
