SpringBoot结合mybatis-plus实现分页的项目实践

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.2</version>
</dependency>

spring:
  datasource:
    driver-class-name: com.mysql.cj.jdbc.Driver
    username: root
    password: 123456
    url: jdbc:mysql://127.0.0.1:3306/test?characterEncoding=utf8&useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true
server:
  port: 9090
mybatis-plus:
  mapper-locations: classpath:mapper/*.xml
  # 控制台打印sql语句
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

create table user
(
	id int(20) auto_increment comment 'id',
	username varchar(20) null comment '用户名',
	gender tinyint null comment '''0未知 1男 2女',
	password varchar(32) null comment '密码',
	age int(4) null comment '年龄',
	create_time datetime null comment '创建时间',
	constraint user_pk
	primary key (id)
)
comment '测试用户表';

@Data
@TableName(value = "user")
public class UserEntity{
    /**
     * id
     */
    @TableId
    private Long id;
    /**
     * 用户名
     */
    private String username;
    /**
     * 密码
     */
    private String password;
    /**
     * 0未知 1男 2女
     */
    private Integer gender;
    /**
     * 年龄
     */
    private Integer age;
}

@Configuration
public class MybatisPlusConfig{
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        PaginationInnerInterceptor paginationInnerInterceptor = new PaginationInnerInterceptor();
        paginationInnerInterceptor.setOptimizeJoin(true);
        paginationInnerInterceptor.setDbType(DbType.MYSQL);
        paginationInnerInterceptor.setOverflow(true);
        interceptor.addInnerInterceptor(paginationInnerInterceptor);
        OptimisticLockerInnerInterceptor optimisticLockerInnerInterceptor = new OptimisticLockerInnerInterceptor();
        interceptor.addInnerInterceptor(optimisticLockerInnerInterceptor);
        return interceptor;
    }
}

<?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.demoutils.easyexcel.mapper.UserMapper">
    <sql id = "entity">
        a.id,a.username,a.password,a.gender,a.age,a.create_time
    </sql>
    <select id="selectUserByGender" resultType="com.example.demoutils.easyexcel.entity.UserEntity">
        select <include refid="entity"/> from user a
        <where>
            <if test="gender != null">
                and a.gender = #{gender}
            </if>
        </where>
    </select>
</mapper>