1.pom.xml
<?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>2.6.0</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
</properties>
<dependencies>
<!--web开发的起步依赖-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--模板-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<!--测试工具-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
<exclusions>
<exclusion>
<groupId>org.junit.vintage</groupId>
<artifactId>junit-vintage-engine</artifactId>
</exclusion>
</exclusions>
</dependency>
<!--开发者工具-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<!--mybatis-plus-->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.5.0</version>
</dependency>
<!--mysql-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
<!--lombok-->
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-core</artifactId>
<version>3.5.0</version>
</dependency>
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis-spring</artifactId>
<version>2.0.6</version>
</dependency>
</dependencies>
<build>
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.yml</include>
<include>**/*.xml</include>
<include>**/*.properties</include>
<!--加载模板文件-->
<include>**/*.html</include>
<!--加载静态文件-->
<include>/static/</include>
</includes>
</resource>
</resources>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<excludes>
<exclude>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</exclude>
</excludes>
</configuration>
</plugin>
</plugins>
</build>
</project>
2.application.properties
spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/mybatis_plus?serverTimezone=GMT%2B8
spring.datasource.username=root
spring.datasource.password=root
spring.thymeleaf.check-template-location=false
#mybatis日志
mybatis-plus.configuration.log-impl=org.apache.ibatis.logging.stdout.StdOutImpl
3.MySQL
CREATE TABLE `user` (
`id` bigint(20) NOT NULL COMMENT '主键ID',
`name` varchar(30) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL COMMENT '姓名',
`age` int(11) DEFAULT NULL COMMENT '年龄',
`email` varchar(50) DEFAULT NULL COMMENT '邮箱',
`create_time` datetime DEFAULT NULL,
`update_time` datetime DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;
4.Entity
package com.example.demo.entity;
import com.baomidou.mybatisplus.annotation.FieldFill;
import com.baomidou.mybatisplus.annotation.TableField;
import lombok.Data;
import java.util.Date;
@Data
public class User {
private Long id;
private String name;
private Integer age;
private String email;
@TableField(value = "create_time", fill = FieldFill.INSERT)
private Date createTime;
@TableField(value = "update_time", fill = FieldFill.INSERT_UPDATE)
private Date updateTime;
}
5.Mapper
package com.example.demo.mapper;
import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.example.demo.entity.User;
import org.springframework.stereotype.Repository;
@Repository
public interface UserMapper extends BaseMapper<User> {
}
6.Handler
package com.example.demo.handler;
import com.baomidou.mybatisplus.core.handlers.MetaObjectHandler;
import org.apache.ibatis.reflection.MetaObject;
import org.springframework.stereotype.Component;
import java.util.Date;
@Component
public class MyMetaObjectHandler implements MetaObjectHandler {
// 执行添加操作，这个方法执行
@Override
public void insertFill(MetaObject metaObject) {
this.setFieldValByName("createTime", new Date(), metaObject);
this.setFieldValByName("updateTime", new Date(), metaObject);
}
// 执行更新操作，这个方法执行
@Override
public void updateFill(MetaObject metaObject) {
this.setFieldValByName("updateTime", new Date(), metaObject);
}
}
7.Test
package com.example.demo;
import com.example.demo.entity.User;
import com.example.demo.mapper.UserMapper;
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 DemoApplicationTests {
@Autowired
private UserMapper userMapper;
// 查询操作
@Test
public void findAll() {
List<User> users = userMapper.selectList(null);
System.out.println(users);
}
// 添加操作
@Test
public void testAdd() {
User user = new User();
user.setName("php");
user.setAge(20);
user.setEmail("123@qq.com");
int insert = userMapper.insert(user);
System.out.println(insert);
}
// 更新操作
@Test
public void testUpdate() {
User user = new User();
user.setId(1485617339597520897L);
user.setName("mybatis");
int i = userMapper.updateById(user);
System.out.println(i);
}
}
