这篇文章主要介绍怎么在SpringBoot中使用Druid数据库连接池,文中介绍的非常详细,具有一定的参考价值,感兴趣的小伙伴们一定要看完!
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SpringBoot2.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: 8080spring: 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;@Configurationpublic 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DataSourcepublic DataSource dataSource() {DruidDataSource datasource = new DruidDataSource();datasource.setUrl(dbUrl);datasource.setUsername(username);datasource.setPassword(password);datasource.setDriverClassName(driverClassName);// configurationdatasource.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@ServletComponentScanpublic 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。
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