目录

1、设置分页拦截器

2、创建数据库及表

3、pom.xml

4、添加MP的相关配置信息 application.yml

5、根据数据库表创建实体类 User

6、创建 UserDao 接口

7、编写引导类

8、编写测试类

9、Run的运行结果

---

1、设置分页拦截器

package com.example.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;
@Configuration
public class MpConfig {
    @Bean
    public MybatisPlusInterceptor mybatisPlusInterceptor() {
        MybatisPlusInterceptor interceptor = new MybatisPlusInterceptor();
        interceptor.addInnerInterceptor(new PaginationInnerInterceptor(DbType.MYSQL));
        return interceptor;
    }
}

2、创建数据库及表

create database if not exists mybatisplus_db character set utf8;
use mybatisplus_db;
CREATE TABLE user (
    id bigint(20) primary key auto_increment,
    name varchar(32) not null,
    password  varchar(32) not null,
    age int(3) not null ,
    tel varchar(32) not null
);
insert into user values(1,'Tom','tom',3,'18866668888');
insert into user values(2,'Jerry','jerry',4,'16688886666');
insert into user values(3,'Jock','123456',41,'18812345678');
insert into user values(4,'小明','xm',15,'4006184000');

3、pom.xml

• springboot版本是 2.5.0

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.5.0</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>

    <!-- Generated by https://start.springboot.io -->
    <!-- 优质的 spring/boot/data/security/cloud 框架中文文档尽在 => https://springdoc.cn -->
    <groupId>com.example</groupId>
    <artifactId>mp_demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mp_demo</name>
    <description>mp_demo</description>
    <properties>
        <java.version>17</java.version>
    </properties>
    <dependencies>

        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.4.1</version>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>

        <!--<dependency>
            <groupId>com.mysql</groupId>
            <artifactId>mysql-connector-j</artifactId>
            <version>8.0.32</version>
            <scope>runtime</scope>
        </dependency>-->

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>


        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>


        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.16</version>
        </dependency>

        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.26</version>
        </dependency>

    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

4、添加MP的相关配置信息 application.yml

spring:
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: com.mysql.cj.jdbc.Driver
    url: jdbc:mysql://localhost:3306/mybatisplus_db?serverTimezone=Asia/Shanghai
    username: root
    password: 123456
# 开启mp的日志（输出到控制台）
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

5、根据数据库表创建实体类 User

package com.example.model;
import lombok.Data;

@Data
public class User {
    private Long id;
    private String name;
    private String password;
    private Integer age;
    private String tel;
    //setter...getter...toString方法略
}

6、创建 UserDao 接口

package com.example.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.model.User;
import org.apache.ibatis.annotations.Mapper;
@Mapper
public interface UserDao extends BaseMapper<User> {
}

7、编写引导类

package com.example;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;


// Generated by https://start.springboot.io
// 优质的 spring/boot/data/security/cloud 框架中文文档尽在 => https://springdoc.cn
@SpringBootApplication
//@MapperScan("com.example.mp_demo.mapper")
public class Mybatisplus01QuickstartApplication {
    public static void main(String[] args) {
        SpringApplication.run(Mybatisplus01QuickstartApplication.class, args);
    }

}

8、编写测试类

package com.example;

import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.example.mapper.UserDao;
import com.example.model.User;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import java.util.List;

@SpringBootTest
class Mybatisplus01QuickstartApplicationTests {

    @Autowired
    private UserDao userDao;

    @Test
    void testGetAll() {
        List<User> userList = userDao.selectList(null);
        userList.forEach(System.out::println);
    }

    @Test
    void testGetByPage() {
        // IPage对象封装了分页操作相关的数据
        IPage<User> page = new Page<>(1, 2);
        userDao.selectPage(page, null);
        System.out.println("当前页码值：" + page.getCurrent());
        System.out.println("每页显示数：" + page.getSize());
        System.out.println("总记录数：" + page.getTotal());
        System.out.println("总页码数：" + page.getPages());
        System.out.println("当前页数据：");
        page.getRecords().forEach(System.out::println);
    }

}

9、Run的运行结果

JDBC Connection [com.mysql.cj.jdbc.ConnectionImpl@3b35798] will not be managed by Spring
==>  Preparing: SELECT COUNT(*) FROM user
==> Parameters: 
<==    Columns: COUNT(*)
<==        Row: 4
<==      Total: 1
==>  Preparing: SELECT id,name,password,age,tel FROM user LIMIT ?
==> Parameters: 2(Long)
<==    Columns: id, name, password, age, tel
<==        Row: 1, Tom, tom, 3, 18866668888
<==        Row: 2, Jerry, jerry, 4, 16688886666
<==      Total: 2
Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@778a1250]
当前页码值：1
每页显示数：2
总记录数：4
总页码数：2
当前页数据：
User(id=1, name=Tom, password=tom, age=3, tel=18866668888)
User(id=2, name=Jerry, password=jerry, age=4, tel=16688886666)