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如何在SpringBoot 中使用 Druid 数据库连接池

Druid 是阿里开源的一款 数据库 连接池 ,除了常规的连接池功能外,它还提供了强大的监控和扩展功能。这对没有做数据库监控的小项目有很大的吸引力。

下列步骤可以让你无脑式的在 SpringBoot 2.x中使用Druid。

1.Maven中的pom文件

<dependency> <groupId> com.alibaba </groupId> <artifactId> druid </artifactId> <version> 1.1.14 </version> </dependency> <dependency> <groupId> log4j </groupId> <artifactId> log4j </artifactId> <version> 1.2.17 </version> </dependency>

使用 Spring Boot-2.x时,如果未引入log4j,在配置 Druid 时,会遇到Caused by: java.lang.ClassNotFoundException: org.apache.log4j.Priority的报错。因为Spring Boot默认使用的是log4j2。

2.SpringBoot 配置文件

下面是一个完整的yml文件的,其中使用mybatis作为数据库访问框架

server : servlet : context - path : / session : timeout : 60m port : 8080   spring : datasource : url : jdbc : mysql : //127.0.0.1:9080/hospital?allowMultiQueries=true&useUnicode=true&characterEncoding=UTF-8&zeroDateTimeBehavior=convertToNull username : root password : root # 环境 dev|test|pro profiles : active : dev driver - class - name : com . mysql . cj . jdbc . Driver   ########################## druid配置 ########################## type : com . alibaba . druid . pool . DruidDataSource # 初始化大小,最小,最大 initialSize : 5 minIdle : 1 maxActive : 20 # 配置获取连接等待超时的时间 maxWait : 60000 # 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 # 校验SQL,Oracle配置 validationQuery=SELECT 1 FROM DUAL,如果不配validationQuery项,则下面三项配置无用 validationQuery : SELECT 1 FROM DUAL testWhileIdle : true testOnBorrow : false testOnReturn : false # 打开PSCache,并且指定每个连接上PSCache的大小 poolPreparedStatements : true maxPoolPreparedStatementPerConnectionSize : 20 # 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 # 通过connectProperties属性来打开mergeSql功能;慢SQL记录 connectionProperties : druid . stat . mergeSql = true ; druid . stat . slowSqlMillis = 5000 # 合并多个DruidDataSource的监控数据 useGlobalDataSourceStat : true   # Mybatis配置 mybatis : mapperLocations : classpath : mapper /*.xml,classpath:mapper/extend/*.xml configuration: map-underscore-to-camel-case: true log-impl: org.apache.ibatis.logging.stdout.StdOutImpl

3.配置Druid数据源实例

由于Druid暂时不在Spring Boot中的直接支持,故需要进行配置信息的定制:

SpringBoot中的配置信息无法再Druid中直接生效,需要在Spring容器中实现一个DataSource实例。

import java . sql . SQLException ; import javax . sql . DataSource ; import org . apache . log4j . Logger ; import org . springframework . beans . factory . annotation . Value ; import org . springframework . context . annotation . Bean ; import org . springframework . context . annotation . Configuration ; import org . springframework . context . annotation . Primary ;   import com . alibaba . druid . pool . DruidDataSource ;   @Configuration public class DruidDBConfig { private Logger logger = Logger . getLogger ( this . getClass ()); //log4j日志   @Value ( "${spring.datasource.url}" ) private String dbUrl ;   @Value ( "${spring.datasource.username}" ) private String username ;   @Value ( "${spring.datasource.password}" ) private String password ;   @Value ( "${spring.datasource.driver-class-name}" ) private String driverClassName ;   @Value ( "${spring.datasource.initialSize}" ) private int initialSize ;   @Value ( "${spring.datasource.minIdle}" ) private int minIdle ;   @Value ( "${spring.datasource.maxActive}" ) private int maxActive ;   @Value ( "${spring.datasource.maxWait}" ) private int maxWait ;   @Value ( "${spring.datasource.timeBetweenEvictionRunsMillis}" ) private int timeBetweenEvictionRunsMillis ;   @Value ( "${spring.datasource.minEvictableIdleTimeMillis}" ) private int minEvictableIdleTimeMillis ;   @Value ( "${spring.datasource.validationQuery}" ) private String validationQuery ;   @Value ( "${spring.datasource.testWhileIdle}" ) private boolean testWhileIdle ;   @Value ( "${spring.datasource.testOnBorrow}" ) private boolean testOnBorrow ;   @Value ( "${spring.datasource.testOnReturn}" ) private boolean testOnReturn ;   @Value ( "${spring.datasource.poolPreparedStatements}" ) private boolean poolPreparedStatements ;   @Value ( "${spring.datasource.maxPoolPreparedStatementPerConnectionSize}" ) private int maxPoolPreparedStatementPerConnectionSize ;   @Value ( "${spring.datasource.filters}" ) private String filters ;   @Value ( "{spring.datasource.connectionProperties}" ) private String connectionProperties ;   @Bean // 声明其为Bean实例 @Primary // 在同样的DataSource中,首先使用被标注的DataSource public DataSource dataSource () { DruidDataSource datasource = new DruidDataSource ();   datasource . setUrl ( dbUrl ); datasource . setUsername ( username ); datasource . setPassword ( password ); datasource . setDriverClassName ( driverClassName );   // configuration datasource . setInitialSize ( initialSize ); datasource . setMinIdle ( minIdle ); datasource . setMaxActive ( maxActive ); datasource . setMaxWait ( maxWait ); datasource . setTimeBetweenEvictionRunsMillis ( timeBetweenEvictionRunsMillis ); datasource . setMinEvictableIdleTimeMillis ( minEvictableIdleTimeMillis ); datasource . setValidationQuery ( validationQuery ); datasource . setTestWhileIdle ( testWhileIdle ); datasource . setTestOnBorrow ( testOnBorrow ); datasource . setTestOnReturn ( testOnReturn ); datasource . setPoolPreparedStatements ( poolPreparedStatements ); datasource . setMaxPoolPreparedStatementPerConnectionSize ( maxPoolPreparedStatementPerConnectionSize ); try { datasource . setFilters ( filters ); } catch ( SQLException e ) { //logger.error("druid configuration initialization filter", e); logger . error ( "druid configuration initialization filter" , e ); e . printStackTrace (); } datasource . setConnectionProperties ( connectionProperties );   return datasource ; }   }

4.过滤器和Servlet

还需要实现一个过滤器和Servlet,用于访问统计页面。

过滤器

import javax . servlet . annotation . WebFilter ; import javax . servlet . annotation . WebInitParam ; import com . alibaba . druid . support . http . WebStatFilter ; @WebFilter ( filterName = "druidWebStatFilter" , urlPatterns = "/*" , initParams ={ @WebInitParam ( name = "exclusions" , value = "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*" ) //忽略资源 } ) public class DruidStatFilter extends WebStatFilter { }

Servlet

import javax . servlet . annotation . WebInitParam ; import javax . servlet . annotation . WebServlet ;   import com . alibaba . druid . support . http . StatViewServlet ;   @WebServlet ( urlPatterns = "/druid/*" , initParams ={ @WebInitParam ( name = "allow" , value = "127.0.0.1,192.168.163.1" ), // IP白名单(没有配置或者为空,则允许所有访问) @WebInitParam ( name = "deny" , value = "192.168.1.73" ), // IP黑名单 (存在共同时,deny优先于allow) @WebInitParam ( name = "loginUsername" , value = "admin" ), // 用户名 @WebInitParam ( name = "loginPassword" , value = "admin" ), // 密码 @WebInitParam ( name = "resetEnable" , value = "false" ) // 禁用HTML页面上的[Reset All]功能 }) public class DruidStatViewServlet extends StatViewServlet { private static final long serialVersionUID = - 2688872071445249539L ;   }

5.使用@ServletComponentScan注解,

使得刚才创建的Servlet,Filter能被访问,SpringBoot扫描并注册。

@SpringBootApplication () @MapperScan ( "cn.china.mytestproject.dao" ) //添加servlet组件扫描,使得Spring能够扫描到我们编写的servlet和filter @ServletComponentScan public class MytestprojectApplication { public static void main ( String [] args ) { SpringApplication . run ( MytestprojectApplication . class , args ); } }

6.Dao层

接着Dao层代码的实现,可以使用mybatis,或者JdbcTemplate等。此处不举例。

7.运行

访问http://localhost:8080/druid/login.html地址即可打开登录页面,账号在之前的Servlet代码中。

至此完成。

要了解更多,访问: https://github测试数据/alibaba/druid

以上就是SpringBoot 中使用 Druid 数据库连接池的实现步骤的详细内容,更多关于SpringBoot 中使用 Druid 数据库连接池的资料请关注其它相关文章!

原文链接:https://cloud.tencent测试数据/developer/article/1402862

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