一、maven配置

<mybatis-plus.version>3.2.0</mybatis-plus.version>
<mysql-connector.version>8.0.13</mysql-connector.version>
<druid-spring-boot.version>1.1.22</druid-spring-boot.version>
<lombok.version>1.16.18</lombok.version>

<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>${mybatis-plus.version}</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>${druid-spring-boot.version}</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>${mysql-connector.version}</version>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
    <version>${lombok.version}</version>
</dependency>

二、修改配置文件

application.yml 

# 打印Mysql查询日志
logging:
  level:
    com.baijia.umetric.dao.mapper: debug

# mybatis插件打印日志，打印查询结果
mybatis-plus:
  configuration:
    log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

spring:
  main:
    allow-bean-definition-overriding: true
  # 延迟加载
  jpa:
    open-in-view: false

jdbc.properties

db-metric.datasource.name=metric-db
db-metric.datasource.type=com.alibaba.druid.pool.DruidDataSource
db-metric.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
db-metric.datasource.url=jdbc:mysql://ip地址:3306/measures_dict?\
    allowMultiQueries=true&useUnicode=true&characterEncoding=UTF8&autoReconnect=true&zeroDateTimeBehavior=convertToNull
db-metric.datasource.username=root    
db-metric.datasource.password=root
#最大连接池数量
db-metric.datasource.max-active=200
#获取连接时最大等待时间，单位毫秒.配置之后，缺省启用公平锁，并发效率会有所下降
db-metric.datasource.max-wait=10000
#初始化时建立物理连接的个数
db-metric.datasource.initial-size=10
# 用来检测连接是否有效的sql，要求是一个查询语句
db-metric.datasource.validation-query=SELECT 1
#申请连接时执行validationQuery检测连接是否有效，配置会降低性能
db-metric.datasource.test-on-borrow=false
#归还连接时执行validationQuery检测连接是否有效，配置会降低性能
db-metric.datasource.test-while-idle=true
#Destroy线程会检测连接的间隔时间，如果连接空闲时间大于等于minEvictableIdleTimeMillis则关闭物理连接
db-metric.datasource.time-between-eviction-runs-millis=18800

java的config目录新增MetricDbConfig.java

package com.baijia.umetric.config;

import javax.sql.DataSource;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Primary;
import org.springframework.context.annotation.PropertySource;

import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;

import lombok.extern.slf4j.Slf4j;

@Configuration
@Slf4j
@PropertySource("classpath:jdbc.properties")
@MapperScan("com.baijia.umetric.dao.mapper")
public class MetricDbConfig {

    @Primary
    @Bean
    @ConfigurationProperties(prefix = "db-metric.datasource")
    public DataSource dataSource() {
        log.info("-------------------- metric DataSource init ---------------------");
        return DruidDataSourceBuilder.create().build();
    }
}

新增分页插件配置 MybatisPlusConfig.java

package com.baijia.umetric.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import com.baomidou.mybatisplus.extension.plugins.PaginationInterceptor;

@Configuration
public class MybatisPlusConfig {

    @Bean
    public PaginationInterceptor paginationInterceptor() {
        return new PaginationInterceptor();
    }
}

 

三、使用

MetricDTO.java

import java.util.Date;

import com.baomidou.mybatisplus.annotation.IdType;
import com.baomidou.mybatisplus.annotation.TableField;
import com.baomidou.mybatisplus.annotation.TableId;
import com.baomidou.mybatisplus.annotation.TableName;
import com.fasterxml.jackson.annotation.JsonFormat;

import lombok.Data;

@TableName("metrices")
@Data
public class MetricDTO {
    //主键
    @TableId(type = IdType.AUTO)
    private Integer id;
    
    //精度，保留小数点位数
    @TableField("`precision`")
    private Integer precision;
}

MetricMapper.java

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
@Mapper
public interface MetricMapper extends BaseMapper<MetricDTO> {
}

Service层使用

LambdaQueryWrapper<MetricDTO> userQueryWrapper = Wrappers.lambdaQuery();
userQueryWrapper.like(MetricDTO::getNameCn,"test");
Page<MetricDTO> page= new Page<>(1, 1);
metricMapper.selectPage(page, userQueryWrapper);