1.什么是Druid？

Druid是阿里的开源库，是Java语言中最好的数据库连接池。Druid能够提供强大的监控和扩展功能。
还有其实Druidf翻译过来就是大名鼎鼎的德鲁伊！看样子大神们都是很调皮的阿。

大德鲁伊（Arch-Druid）：玛法里奥·怒风

2. 配置Druid

其实大多数在GitHub上已经写的比较明白了。Maven参考文档。
参考https://github.com/alibaba/druid即可，但是还是有配置上的小坑，这里就列下配置文件。

applicaition.yml:

spring:
  datasource:
    username: root
    password: 123456
    url: jdbc:mysql://192.168.15.128:3306/jdbc
    driver-class-name: com.mysql.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
    #dataSource Pool configuration
    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

DruidConfig:

package com.example.jdbc.config;

import com.alibaba.druid.pool.DruidDataSource;
import com.alibaba.druid.spring.boot.autoconfigure.DruidDataSourceBuilder;
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 org.springframework.context.annotation.Primary;

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

/**
 * @author BaoZhou
 * @date 2018/5/25
 */
@Configuration
public class DruidConfig {
    @ConfigurationProperties(prefix = "spring.datasource")
    @Bean
    public DataSource druid(){
        return DruidDataSourceBuilder.create().build();
    }
    @Bean
    public ServletRegistrationBean startViewServlet()
    {
        //参数可以在StatViewServlet和ResourceServlet中查看
        ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(),"/druid/*");
        Map<String,String> params = new HashMap<>();
        //用户名
        params.put("loginUsername","admin");
        //密码
        params.put("loginPassword","123456");
        //IP白名单 (不填写代表允许所有IP)
        params.put("allow","");
        //IP黑名单 (存在共同时，deny优先于allow)
        //initParameters.put("deny", "192.168.20.38");
        bean.setInitParameters(params);
        return bean;
    }

    @Bean
    public FilterRegistrationBean webStatFilter(){
        FilterRegistrationBean bean = new FilterRegistrationBean();
        bean.setFilter(new WebStatFilter());
        Map<String,String> initParams = new HashMap<>();
        //排除拦截
        initParams.put("exclusions","*.js,*.css,/druid/*");
        bean.setInitParameters(initParams);
        bean.setUrlPatterns(Arrays.asList("/*"));
        return  bean;
    }
}

运行后即可登录http://localhost:8080/druid/login.html查看监控讯息。

监控讯息 监控讯息

总的来说就是十分简单好用的数据库连接池，当然更多高级用法还是要参考GitHub文档。