使用springboot不自动初始化数据库连接池使用springboot不自动初始化数据

springboot不自动初始化数据库连接池

简介
解决方案

记录下spring boot关于数据库连接池的一个小坑

application.properties配置
先找到这个类
在下面的源码中打个断点
启动项目

springboot不自动初始化数据库连接池
简介
有时候我们想自己动态的初始化数据库连接池，但是springboot 的@SpringBootApplication注解会自动去初始化数据库连接池，不配置的话会启动失败，如下提示

Exception encountered during context initialization - cancelling refresh attempt: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'dataSource' defined in class path resource [org/springframework/boot/autoconfigure/jdbc/DataSourceConfiguration$Dbcp2.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.apache.commons.dbcp2.BasicDataSource]: Factory method 'dataSource' threw exception; nested exception is org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Failed to determine a suitable driver class
INFO - Unregistering JMX-exposed beans on shutdown

解决方案
办法就是排除自动初始化的类

@SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})public class Application implements CommandLineRunner {...}

加上这么一句

(exclude = {DataSourceAutoConfiguration.class})

就可以跳过数据库的自动初始化，自己为所欲为了~

记录下spring boot关于数据库连接池的一个小坑环境：spring boot 1.5、JDK1.8

application.properties配置

# 驱动配置信息spring.datasource.url = jdbc:mysql://127.0.0.1:3306/mealsystem?useUnicode=true&characterEncoding=utf-8spring.datasource.username = rootspring.datasource.password = 123456spring.datasource.driverClassName = com.mysql.jdbc.Driver#连接池的配置信息spring.datasource.initialSize=5spring.datasource.minIdle=5spring.datasource.maxActive=20spring.datasource.maxWait=60000spring.datasource.timeBetweenEvictionRunsMillis=60000spring.datasource.minEvictableIdleTimeMillis=300000spring.datasource.validationQuery=SELECT 1 FROM DUALspring.datasource.testWhileIdle=truespring.datasource.testOnBorrow=falsespring.datasource.testOnReturn=falsespring.datasource.poolPreparedStatements=truespring.datasource.maxPoolPreparedStatementPerConnectionSize=20spring.datasource.filters=stat,wall,log4jspring.datasource.connectionProperties=druid.stat.mergeSql=true; druid.stat.slowSqlMillis=5000

先找到这个类

org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder

在下面的源码中打个断点

public DataSource build() {Class type = this.getType(); DataSource result = (DataSource)BeanUtils.instantiate(type); this.maybeGetDriverClassName(); this.bind(result); return result; }

启动项目

文章图片

我们可以发现，在没有配置spring.datasource.type时，spring boot默认的连接池是tomcat-jdbc
也就是说我们在application.properties中配置的连接池参数是无效的。
好，那我们再配置下这个属性，使用阿里巴巴的druid

spring.datasource.type=com.alibaba.druid.pool.DruidDataSource

再启动下

文章图片

再来看看1.5版本org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder的源码

private static final String[] DATA_SOURCE_TYPE_NAMES = new String[] {"org.apache.tomcat.jdbc.pool.DataSource","com.zaxxer.hikari.HikariDataSource","org.apache.commons.dbcp.BasicDataSource", // deprecated"org.apache.commons.dbcp2.BasicDataSource" };