mybaties-plus分页

MyBatis Plus自带分页插件，只要简单的配置即可实现分页功能

1. pom.xml添加依赖

注意：mybaties-plus版本的问题，可能导致出现错误，此处使用的是3.5.1版本

<!-- https://mvnrepository.com/artifact/com.baomidou/mybatis-plus -->
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus</artifactId>
    <version>3.5.1</version>
</dependency>

2. 添加配置类

package com.example.demo.commoms.config;

import com.baomidou.mybatisplus.annotation.DbType;
import com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor;
import com.baomidou.mybatisplus.extension.plugins.inner.PaginationInnerInterceptor;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * mybaties-plus分页配置
 * @author admin
 */
@Configuration
public class MybatisPlusConfig {

    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

3. 测试分页

通过mapper的自带的selectPage方法进行分页查询

package com.example.demo.role;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.example.demo.dao.IRoleMapper;
import com.example.demo.entity.Role;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import javax.annotation.Resource;

@Slf4j
@RunWith(SpringRunner.class)
@SpringBootTest
public class GetPageRoleTest {

    @Resource
    IRoleMapper roleMapper;

    private static final Integer current = 1;
    private static final Integer pageSize = 5;
    
    /**
     * 通过mapper的自带的selectPage方法进行分页查询
     * */
    @Test
    public void GetPageRole() {
        Page<Role> rolePage = new Page<>(current, pageSize);
        QueryWrapper<Role> queryWrapper = new QueryWrapper<>();
        Page<Role> page = roleMapper.selectPage(rolePage, queryWrapper);
        System.out.println("total: " + page.getTotal());
        System.out.println("current: " + page.getCurrent());
        System.out.println("page: " + page.getSize());
    }
}

4. 自定义分页

4.1 Mapper文件

@Mapper
public interface IRoleMapper extends BaseMapper<Role> {
    IPage<Role> selectRoleByPage(Page<?> page);
}

4.2 对应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.example.demo.dao.IRoleMapper">

    <resultMap id="BaseResultMap" type="com.example.demo.entity.Role">
        <id property="roleId" column="role_id" jdbcType="VARCHAR"/>
        <result property="name" column="name" jdbcType="VARCHAR"/>
        <result property="createTime" column="create_time" jdbcType="TIMESTAMP"/>
        <result property="updateTime" column="update_time" jdbcType="TIMESTAMP"/>
        <result property="status" column="status" jdbcType="INTEGER"/>
    </resultMap>
    <select id="selectRoleByPage" resultType="com.example.demo.entity.Role">
        SELECT * FROM role;
    </select>
</mapper>

4.3 测试

package com.example.demo.role;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.example.demo.dao.IRoleMapper;
import com.example.demo.entity.Role;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import javax.annotation.Resource;

@Slf4j
@RunWith(SpringRunner.class)
@SpringBootTest
public class GetPageRoleTest {

    @Resource
    IRoleMapper roleMapper;

    private static final Integer current = 2;
    private static final Integer pageSize = 5;
    
    /**
     * // 通过自定义mapper进行分页查询
     * */
    @Test
    public void GetPageRoleByCustomer() {
        Page<Role> rolePage = new Page<>(current, pageSize);
        IPage<Role> roleIPage = roleMapper.selectRoleByPage(rolePage);
        System.out.println("total: " + roleIPage.getTotal());
        System.out.println("current: " + roleIPage.getCurrent());
        System.out.println("page: " + roleIPage.getSize());
    }
}