数据库druid连接池突然报错版本1.1.9
报错：java.sql.SQLException: Closed Statement
Cause: java.sql.SQLException: Closed Statement
; uncategorized SQLException for SQL []; SQL state [99999]; error code [17009]; Closed Statement; nested exception is java.sql.SQLException: Closed Statement
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:84) ~[spring-jdbc-4.3.9.RELEASE.jar:4.3.9.RELEASE]
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81) ~[spring-jdbc-4.3.9.RELEASE.jar:4.3.9.RELEASE]
at org.springframework.jdbc.support.AbstractFallbackSQLExceptionTranslator.translate(AbstractFallbackSQLExceptionTranslator.java:81) ~[spring-jdbc-4.3.9.RELEASE.jar:4.3.9.RELEASE]
at org.mybatis.spring.MyBatisExceptionTranslator.translateExceptionIfPossible(MyBatisExceptionTranslator.java:73) ~[mybatis-spring-1.3.2.jar:1.3.2]
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:446) ~[mybatis-spring-1.3.2.jar:1.3.2]
at com.sun.proxy.$Proxy43.selectList(Unknown Source) ~[?:?]
at org.mybatis.spring.SqlSessionTemplate.selectList(SqlSessionTemplate.java:230) ~[mybatis-spring-1.3.2.jar:1.3.2]
aused by: java.sql.SQLException: Closed Statement
at oracle.jdbc.driver.OracleClosedStatement.exitImplicitCacheToActive(OracleClosedStatement.java:2957) ~[ojdbc8-19.3.0.0.0.jar:19.3.0.0.0]
at oracle.jdbc.driver.OraclePreparedStatementWrapper.exitImplicitCacheToActive(OraclePreparedStatementWrapper.java:1249) ~[ojdbc8-19.3.0.0.0.jar:19.3.0.0.0]
at com.alibaba.druid.util.OracleUtils.exitImplicitCacheToActive(OracleUtils.java:80) ~[druid-1.1.9.jar:1.1.9]
at com.alibaba.druid.pool.PreparedStatementPool.get(PreparedStatementPool.java:66) ~[druid-1.1.9.jar:1.1.9]
at com.alibaba.druid.pool.DruidPooledConnection.prepareStatement(DruidPooledConnection.java:344) ~[druid-1.1.9.jar:1.1.9]
at sun.reflect.GeneratedMethodAccessor17.invoke(Unknown Source) ~[?:?]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_201]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_201]
at org.apache.ibatis.logging.jdbc.ConnectionLogger.invoke(ConnectionLogger.java:55) ~[mybatis-3.4.6.jar:3.4.6]
at com.sun.proxy.$Proxy54.prepareStatement(Unknown Source) ~[?:?]
at org.apache.ibatis.executor.statement.PreparedStatementHandler.instantiateStatement(PreparedStatementHandler.java:87) ~[mybatis-3.4.6.jar:3.4.6]
at org.apache.ibatis.executor.statement.BaseStatementHandler.prepare(BaseStatementHandler.java:88) ~[mybatis-3.4.6.jar:3.4.6]
at org.apache.ibatis.executor.statement.RoutingStatementHandler.prepare(RoutingStatementHandler.java:59) ~[mybatis-3.4.6.jar:3.4.6]
at org.apache.ibatis.executor.SimpleExecutor.prepareStatement(SimpleExecutor.java:85) ~[mybatis-3.4.6.jar:3.4.6]
at org.apache.ibatis.executor.SimpleExecutor.doQuery(SimpleExecutor.java:62) ~[mybatis-3.4.6.jar:3.4.6]
at org.apache.ibatis.executor.BaseExecutor.queryFromDatabase(BaseExecutor.java:326) ~[mybatis-3.4.6.jar:3.4.6]
at org.apache.ibatis.executor.BaseExecutor.query(BaseExecutor.java:156) ~[mybatis-3.4.6.jar:3.4.6]
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:103) ~[mybatis-3.4.6.jar:3.4.6]
at org.apache.ibatis.executor.CachingExecutor.query(CachingExecutor.java:83) ~[mybatis-3.4.6.jar:3.4.6]
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:148) ~[mybatis-3.4.6.jar:3.4.6]
at org.apache.ibatis.session.defaults.DefaultSqlSession.selectList(DefaultSqlSession.java:141) ~[mybatis-3.4.6.jar:3.4.6]
at sun.reflect.GeneratedMethodAccessor29.invoke(Unknown Source) ~[?:?]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_201]
at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_201]
at org.mybatis.spring.SqlSessionTemplate$SqlSessionInterceptor.invoke(SqlSessionTemplate.java:433) ~[mybatis-spring-1.3.2.jar:1.3.2]
... 64 more
这个错误表明某些语句关闭了连接，导致了错误。可能是因为 druid 连接池的版本与 Oracle 的版本不兼容或者是连接池被过度使用导致连接缓存失效。建议升级 druid 连接池或者减少连接池的使用。