springboot便捷配置c3p0

springboot内置支持HikariCP、Tomcat及dbcp2连接池，使用c3p0数据库连接池，除了自定义DataSource bean之外，还可以充分利用c3p0会自动扫描配置文件/c3p0.properties的特点，在resource目录创建c3p0.properties文件并修改配置参数，再通过修改appication.properties的spring.datasource.type指定为spring.datasource.type=com.mchange.v2.c3p0.ComboPooledDataSource即可实现不写java代码使用c3p0。

 

appication.properties配置参考：

spring.datasource.url=jdbc:mysql://localhost/test
spring.datasource.username=dbuser
spring.datasource.password=dbpass
spring.datasource.driver-class-name=com.mysql.jdbc.Driver

spring.datasource.type=com.mchange.v2.c3p0.ComboPooledDataSource

 c3p0.properties文件参考（完整配置项参见https://www.mchange.com/projects/c3p0/#configuration)：

c3p0.minPoolSize=2
c3p0.maxPoolSize=10
c3p0.maxIdleTime=1800000
c3p0.acquireIncrement=3
c3p0.maxStatements=1000
c3p0.initialPoolSize=4
c3p0.idleConnectionTestPeriod=60
c3p0.acquireRetryAttempts=30
c3p0.acquireRetryDelay=1000
c3p0.breakAfterAcquireFailure=true
c3p0.testConnectionOnCheckout=true