才华是刀刃，辛苦是磨刀石，很锋利的刀刃，若日久未磨，依旧会成为废韧——老舍
当程序存在缺陷时，申请的连接忘记关闭，这时候，就存在连接泄漏了
我们使用druid时，可以配置如下参数进行用来关闭长时间不使用的连接
spring: # 数据源配置 datasource: druid: # 统计监控信息 web-stat-filter: enabled: true # 可视化展示Druid的统计信息 stat-view-servlet: enabled: true filter: # sql注入 wall: enabled: true db-type: mysql slf4j: enabled: true statement-sql-pretty-format: true # 保持连接sql validation-query: SELECT 1 FROM DUAL # 保持连接sql超时时间 validation-query-timeout: 600000 # 连接初始化sql connection-init-sqls: - SET NAMES utf8mb4 # 超时后释放连接设置时间 remove-abandoned-timeout-millis: 100 # 超时后释放连接开启 remove-abandoned: true # 超时释放日志 log-abandoned: true # 最大线程数 max-wait: 2000 # 最大等待时间 max-active: 20
这里是abandoned相关配置
这样我们程序则会自动释放忘记关机的连接，并且输出日志信息
2022-01-15 18:49:29.560 ERROR 27396 --- [stroy-507383828] com.alibaba.druid.pool.DruidDataSource : abandon connection, owner thread: pool-2-thread-4, connected at : 1642240141966, open stackTrace at java.lang.Thread.getStackTrace(Thread.java:1559) at com.alibaba.druid.pool.DruidDataSource.getConnectionDirect(DruidDataSource.java:1496) at com.alibaba.druid.filter.FilterChainImpl.dataSource_connect(FilterChainImpl.java:5059) at com.alibaba.druid.filter.FilterAdapter.dataSource_getConnection(FilterAdapter.java:2756) at com.alibaba.druid.filter.FilterChainImpl.dataSource_connect(FilterChainImpl.java:5055) at com.alibaba.druid.filter.logging.LogFilter.dataSource_getConnection(LogFilter.java:917) at com.alibaba.druid.filter.FilterChainImpl.dataSource_connect(FilterChainImpl.java:5055) at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1405) at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:1397) at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:100) at org.springframework.jdbc.datasource.DataSourceUtils.fetchConnection(DataSourceUtils.java:158) at org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:116) at org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:79) at org.mybatis.spring.transaction.SpringManagedTransaction.openConnection(SpringManagedTransaction.java:80) at org.mybatis.spring.transaction.SpringManagedTransaction.getConnection(SpringManagedTransaction.java:67) at org.apache.ibatis.executor.BaseExecutor.getConnection(BaseExecutor.java:337) at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:86) at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:62) at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:325) at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156) at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:109) at com.baomidou.mybatisplus.extension.plugins.MybatisPlusInterceptor.intercept(MybatisPlusInterceptor.java:81) at org.apache.ibatis.plugin.Plugin.invoke(Plugin.java:62) at com.sun.proxy.$Proxy190.query(Unknown Source) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:151) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:145) at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:140) at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.executeForMany(MybatisMapperMethod.java:166) at com.baomidou.mybatisplus.core.override.MybatisMapperMethod.execute(MybatisMapperMethod.java:77) at com.baomidou.mybatisplus.core.override.MybatisMapperProxy$PlainMethodInvoker.invoke(MybatisMapperProxy.java:148) at com.baomidou.mybatisplus.core.override.MybatisMapperProxy.invoke(MybatisMapperProxy.java:89) at com.sun.proxy.$Proxy121.selectList(Unknown Source) at com.baomidou.mybatisplus.extension.toolkit.SimpleQuery.group(SimpleQuery.java:109)
