一、环境配置

1、添加pom依赖

        <!--druid数据源-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.20</version>
        </dependency>

2、添加配置文件

spring:
  datasource:
#   数据源基本配置
    username: root
    password: admin
    driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/jdbc?useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
    type: com.alibaba.druid.pool.DruidDataSource
#   数据源其他配置
    initialSize: 5
    minIdle: 5
    maxActive: 20
    maxWait: 60000
    timeBetweenEvictionRunsMillis: 60000
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    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,log4j
    maxPoolPreparedStatementPerConnectionSize: 20
    useGlobalDataSourceStat: true
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

二、编写druid配置类

创建DruidConfig类

package com.me.study.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;
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.Arrays;
import java.util.HashMap;
import java.util.Map;

@Configuration
public class DruidConfig {
    // @ConfigurationProperties() 将配置文件中的连接池配置添加到数据源
    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid(){
        return new DruidDataSource();
    }

    // 配置Druid的监控     
    // 配置一个管理后台的Servlet
    @Bean
    public ServletRegistrationBean statViewServlet(){
        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean();
        servletRegistrationBean.setServlet(new StatViewServlet());
        // 配置管理后台路径
        servletRegistrationBean.setUrlMappings(Arrays.asList("/druid/*"));
        Map<String,String> initParams = new HashMap<>();
        initParams.put("loginUsername","admin");
        initParams.put("loginPassword","123456");
        initParams.put("allow","");// 配置允许访问的路径，默认允许所有访问
        initParams.put("deny","192.168.1.150"); // 拒绝那些路径访问
        servletRegistrationBean.setInitParameters(initParams);
        return servletRegistrationBean;
    }

    // 配置一个web监控的filter
    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        filterRegistrationBean.setFilter(new WebStatFilter());
        Map<String,String> initParams = new HashMap<>();
        initParams.put("exclusions","*.js,*.css,/druid/*"); //忽略哪些请求，不过滤的请求
        filterRegistrationBean.setInitParameters(initParams);
        filterRegistrationBean.setUrlPatterns(Arrays.asList("/*"));// 过滤所有请求
        return filterRegistrationBean;
    }

}

三、运行测试

1、初次运行

启动时报错(这个错误挺预想不到的)：

***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to bind properties under 'spring.datasource' to javax.sql.DataSource:

    Property: spring.datasource.filters
    Value: stat,wall,log4j
    Origin: class path resource [application.yml]:22:14
    Reason: org.apache.log4j.Logger

Action:

Update your application's configuration

Process finished with exit code 1

2、解决方式

到网上搜索了以下，有个博主和我有一摸一样的问题，所以参考了那位博主的解决方案，博文连接：https://blog.csdn.net/xingkongtianma01/article/details/81624313
错误出现原因是：缺少log4j的相关依赖
所以，添加log4j依赖：

        <dependency>
            <groupId>log4j</groupId>
            <artifactId>log4j</artifactId>
            <version>1.2.17</version>
        </dependency>

3、再次运行

错误解决，运行结果：

druid数据源监控登录界面，用户名密码为以上servlet配置

登录成功，数据监控首页面：

druid数据监控首页面