maven依赖

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-log4j2</artifactId>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-j</artifactId>
    <version>8.3.0</version>
    <scope>runtime</scope>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.2.18</version>
</dependency>

yaml文件配置

spring:
  datasource:
  # 数据源基本配置
  url: jdbc:mysql://localhost:3306/hotel?useUnicode=true&characterEncoding=utf-8&serverTimezone=Asia/Shanghai
  username: root
  password: 123456
  driver-class-name: com.mysql.cj.jdbc.Driver
  type: com.alibaba.druid.pool.DruidDataSource
  # 数据源其他配置
  druid:
    # 配置初始化大小、最小、最大线程数
    initialSize: 5
    minIdle: 5
    # CPU核数+1，也可以大些但不要超过20，数据库加锁时连接过多性能下降
    maxActive: 20
    # 最大等待时间，内网：800，外网：1200（三次握手1s）
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    # 配置一个连接在池中最大空间时间，单位是毫秒
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1
    testWhileIdle: true
    # 设置从连接池获取连接时是否检查连接有效性，true检查，false不检查
    testOnBorrow: true
    # 设置从连接池归还连接时是否检查连接有效性，true检查，false不检查
    testOnReturn: true
    # 可以支持PSCache（提升写入、查询效率）
    poolPreparedStatements: true
    # 配置监控统计拦截的filters，去掉后监控界面sql无法统计，'wall'用于防火墙
    filters: stat,wall,log4j2
    # 保持长连接
    keepAlive: true
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

添加配置类

Spring Boot2:

import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import javax.servlet.Filter;
import javax.servlet.Servlet;


@Configuration
public class DruidConfig {

    /**
    * 配置Druid 监控启动页面
    *
    * @return servletRegistrationBean
    */
    @Bean
    @ConditionalOnMissingBean
    public ServletRegistrationBean<Servlet> druidStartViewServlet() {
        ServletRegistrationBean<Servlet> servletRegistrationBean = new ServletRegistrationBean<Servlet>(new StatViewServlet(), "/druid/*");
        // 白名单
        servletRegistrationBean.addInitParameter("allow", "127.0.0.1");
        // 黑名单
        servletRegistrationBean.addInitParameter("deny", "192.168.1.100");
        // 登录查看信息的账密，用于登录Druid监控后台
        servletRegistrationBean.addInitParameter("loginUsername", "druid");
        servletRegistrationBean.addInitParameter("loginPassword", "druid");
        // 是否能够重置数据
        servletRegistrationBean.addInitParameter("resetEnable", "true");
        return servletRegistrationBean;
    }
    
    /**
    * Druid监控过滤器配置规则
    * ConditionalOnMissingBean 防止注册相同的bean
    *
    * @return filterFilterRegistrationBean
    */
    @Bean
    @ConditionalOnMissingBean
        public FilterRegistrationBean<Filter> filterRegistrationBean() {
        FilterRegistrationBean<Filter> filterFilterRegistrationBean = new FilterRegistrationBean<>();
        filterFilterRegistrationBean.setFilter(new WebStatFilter());
        // 添加过滤规则
        filterFilterRegistrationBean.addUrlPatterns("/*");
        // 添加不需要忽略的格式信息
        filterFilterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");
        return filterFilterRegistrationBean;
    }
}

spring Boot3:

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.jakarta.StatViewServlet;
import com.alibaba.druid.support.jakarta.WebStatFilter;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
import org.springframework.boot.context.properties.ConfigurationProperties;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import javax.sql.DataSource;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Configuration
public class DruidConfig {
    /**
    * 添加 DruidDataSource 组件到容器中，并绑定属性
    */
    @Bean
    @ConfigurationProperties(prefix = "spring.datasource")
    @ConditionalOnProperty(name = "spring.datasource.type", havingValue = "com.alibaba.druid.pool.DruidDataSource")
    public DataSource druid(){
        return new DruidDataSource();
    }

    /**
    * 配置 Druid 监控管理后台的Servlet；
    * 内置 Servlet 容器时没有web.xml文件，所以使用 Spring Boot 的注册 Servlet 方式
    */
    @Bean
    @ConditionalOnClass(DruidDataSource.class)
    public ServletRegistrationBean statViewServlet(){
        // 这些参数可以在 http.StatViewServlet 的父类 ResourceServlet 中找到
        Map<String,String> initParams = new HashMap<>();
        initParams.put("loginUsername","druid");
        initParams.put("loginPassword","druid");
        // allow：Druid 后台允许谁可以访问。默认就是允许所有访问。
        initParams.put("allow",""); // 后面参数为空则所有人都能访问，一般会写一个具体的ip或ip段
        // deny：Druid 后台禁止谁能访问
        // initParams.put("deny","192.168.10.132");

        // 注册一个servlet，同时表明/druid/* 这个请求会走到这个servlet，而druid内置了这个请求的接收
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        bean.setInitParameters(initParams);
        return bean;
    }

    /**
    * 配置一个web监控的filter
    */
    @Bean
    @ConditionalOnClass(DruidDataSource.class)
    public FilterRegistrationBean webStatFilter(){
        Map<String,String> initParams = new HashMap<>();
        // 这些不进行统计
        initParams.put("exclusions","*.js,*.css,/druid/*");

        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new WebStatFilter());
        bean.setInitParameters(initParams);
        bean.setUrlPatterns(List.of("/*"));
        return bean;
    }
}