springboot集成mybatis-plus

1、pom文件引入依赖

<?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>2.2.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.test.springbootdemos</groupId>
    <artifactId>mybatisplus</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>mybatisplus</name>
    <description>Demo project for Spring Boot Integrated With MybatisPlus</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
            <scope>runtime</scope>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>com.baomidou</groupId>
            <artifactId>mybatis-plus-boot-starter</artifactId>
            <version>3.3.1.tmp</version>
        </dependency>
        <!-- 引入Druid依赖，阿里巴巴所提供的数据源 -->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.0.29</version>
        </dependency>
        <!-- 提供mysql驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.38</version>
        </dependency>
        <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>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
<!--        <dependency>-->
<!--            <groupId>org.junit.platform</groupId>-->
<!--            <artifactId>junit-platform-launcher</artifactId>-->
<!--            <version>1.5.2</version>-->
<!--            <scope>test</scope>-->
<!--        </dependency>-->

    </dependencies>

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

</project>

2、application.yml

mysql8.0

#数据源
  spring:
#    security:
#      basic:
#        enabled: false
    datasource:
      type: com.alibaba.druid.pool.DruidDataSource
      url: jdbc:mysql://127.0.0.1:3306/mybatis?useUnicode=true&characterEncoding=utf-8&autoReconnect=true&useSSL=false
      username: root
      password: click1
      driver-class-name: com.mysql.jdbc.Driver
      druid:
        # 初始化时建立物理连接的个数。初始化发生在显示调用init方法，或者第一次getConnection时
        initialSize: 1
        # 最小连接池数量
        minIdle: 1
        # 最大连接池数量
        maxActive: 10
        # 配置获取连接等待超时的时间
        maxWait: 10000
        # 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒
        timeBetweenEvictionRunsMillis: 60000
        # 配置一个连接在池中最小生存的时间，单位是毫秒
        minEvictableIdleTimeMillis: 300000
        # 验证连接有效与否的SQL，不同的数据配置不同
        validationQuery: select 1
        # 建议配置为true，不影响性能，并且保证安全性。
        # 申请连接的时候检测，如果空闲时间大于
        # timeBetweenEvictionRunsMillis，
        # 执行validationQuery检测连接是否有效。
        testWhileIdle: true
        # 申请连接时执行validationQuery检测连接是否有效，做了这个配置会降低性能。
        # 这里建议配置为TRUE，防止取到的连接不可用
        testOnBorrow: true
        # 归还连接时执行validationQuery检测连接是否有效，做了这个配置会降低性能
        testOnReturn: false
        # 是否缓存preparedStatement，也就是PSCache。
        # PSCache对支持游标的数据库性能提升巨大，比如说oracle。
        # 在mysql5.5以下的版本中没有PSCache功能，建议关闭掉。
        # 作者在5.5版本中使用PSCache，通过监控界面发现PSCache有缓存命中率记录，
        # 该应该是支持PSCache。
        # 打开PSCache，并且指定每个连接上PSCache的大小
        poolPreparedStatements: true
        maxPoolPreparedStatementPerConnectionSize: 20
        # 属性类型是字符串，通过别名的方式配置扩展插件，
        # 常用的插件有：
        # 监控统计用的filter:stat
        # 日志用的filter:log4j
        # 防御sql注入的filter:wall
        filters: stat

  # ====================MybatisPlus====================
  mybatis-plus:
    # 如果是放在src/main/java目录下 classpath:/com/yourpackage/*/mapper/*Mapper.xml
    # 如果是放在resource目录 classpath:/mapper/*Mapper.xml
    mapper-locations: classpath*:mapper/*Mapper.xml #默认就在resources/mapper下，如果要更改目录在这个配置下更改
    #实体扫描，多个package用逗号或者分号分隔
    typeAliasesPackage: com.test.springbootdemos.mybatisplus.entity
    global-config:
      #刷新mapper 调试神器
      db-config:
        #主键类型  0:"数据库ID自增", 1:"用户输入ID",2:"全局唯一ID (数字类型唯一ID)", 3:"全局唯一ID UUID";
        id-type: AUTO
        #字段策略 0:"忽略判断",1:"非 NULL 判断"),2:"非空判断"
        field-strategy: 2
        #驼峰下划线转换SELECT id,user_name,user_password FROM t_user
        column-underline: false
        #数据库大写下划线转换SELECT ID,USER_NAME,USER_PASSWORD FROM t_user
#        capital-mode: true
        #逻辑删除配置
        logic-delete-value: 1
        logic-not-delete-value: 0
      refresh: true
    configuration:
      #配置返回数据库(column下划线命名&&返回java实体是驼峰命名)，自动匹配无需as（没开启这个，SQL需要写as： select user_id as userId）
      map-underscore-to-camel-case: true
      cache-enabled: false
      #配置JdbcTypeForNull, oracle数据库必须配置
      jdbc-type-for-null: 'null'
      log-impl: org.apache.ibatis.logging.stdout.StdOutImpl
      database-id: mysql

3、SpringBoot启动类

package com.test.springbootdemos.mybatisplus;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

@SpringBootApplication
@MapperScan("com.test.springbootdemos.mybatisplus.mapper")
public class MybatisplusApplication {

    public static void main(String[] args) {
        SpringApplication.run(MybatisplusApplication.class, args);
    }

}

4、实体类

import com.baomidou.mybatisplus.annotation.TableName;

import java.io.Serializable;

@TableName("t_user")
public class User implements Serializable {
     private String id;

     @TableField(value="username")
     private String userName;

     @TableField(value="userpassword")
     private String userPassword;

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public String getUserPassword() {
        return userPassword;
    }

    public void setUserPassword(String userPassword) {
        this.userPassword = userPassword;
    }

    @Override
    public String toString() {
        return "User{" +
                "id='" + id + '\'' +
                ", userName='" + userName + '\'' +
                ", userPassword='" + userPassword + '\'' +
                '}';
    }
}

5、mapper接口

package com.test.springbootdemos.mybatisplus.mapper;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.test.springbootdemos.mybatisplus.entity.User;
import org.springframework.stereotype.Repository;


//@Repository
public interface UserMapper extends BaseMapper<User> {

}

6、测试类

package com.test.springbootdemos.mybatisplus;

import com.test.springbootdemos.mybatisplus.entity.User;
import com.test.springbootdemos.mybatisplus.mapper.UserMapper;
import org.junit.jupiter.api.Test;
import org.junit.runner.RunWith;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.context.junit4.SpringRunner;

import java.util.List;

@RunWith(SpringRunner.class)
@SpringBootTest
@MapperScan({"com.test.springbootdemos.mybatisplus.mapper"})
class MybatisplusApplicationTests {
    @Autowired
    UserMapper userMapper;

//    @Test
//    void contextLoads() {
//    }


    @Test
    public void testMapper(){
        List<User> userList = userMapper.selectList(null);
        System.out.println("userList:"+userList);
    }
}

7、UserService

package com.test.springbootdemos.mybatisplus.service;

import com.baomidou.mybatisplus.extension.service.IService;
import com.test.springbootdemos.mybatisplus.entity.User;

public interface UserService extends IService<User> {
}

8、UserServiceImpl

package com.test.springbootdemos.mybatisplus.service.impl;

import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.test.springbootdemos.mybatisplus.entity.User;
import com.test.springbootdemos.mybatisplus.mapper.UserMapper;
import com.test.springbootdemos.mybatisplus.service.UserService;
import org.springframework.stereotype.Service;

@Service
public class UserServiceImpl extends ServiceImpl<UserMapper, User> implements UserService {

}

9、UserController

package com.test.springbootdemos.mybatisplus.controller;


import com.test.springbootdemos.mybatisplus.entity.User;
import com.test.springbootdemos.mybatisplus.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.List;

@RestController
@RequestMapping("/user")
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("/getAll")
    public List<User> getAll() {
        List<User> list = userService.list();
        System.out.println("list:" + list);
        return list;
    }
}