nutz连接mysql异常处理:MySQLNonTransientConnectionException: No operations allowed after connection closed 快来打我* 2022-08-10 11:48 118阅读 0赞 异常信息(部分): 2014-11-26 12:01:47,815 \[http-6888-6\] WARN com.mchange.v2.c3p0.impl.NewPooledConnection - \[c3p0\] A PooledConnection that has already signalled a Connection error is still in use! 2014-11-26 12:01:47,829 \[http-6888-6\] WARN com.mchange.v2.c3p0.impl.NewPooledConnection - \[c3p0\] Another error has occurred \[ com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed. \] which will not be reported to listeners! com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed. at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27) at java.lang.reflect.Constructor.newInstance(Constructor.java:513) at com.mysql.jdbc.Util.handleNewInstance(Util.java:408) at com.mysql.jdbc.Util.getInstance(Util.java:383) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1023) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:997) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:983) at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:928) at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1323) at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1315) at com.mysql.jdbc.ConnectionImpl.rollback(ConnectionImpl.java:5057) at com.mchange.v2.c3p0.impl.NewProxyConnection.rollback(NewProxyConnection.java:855) ## 原因分析 ## 查看了Mysql的文档,以及Connector/J的文档以及在线说明发现,出现这种异常的原因是: Mysql服务器默认的“wait\_timeout”是8小时,也就是说一个connection空闲超过8个小时,Mysql将自动断开该connection。这就是问题的所在,在C3P0 pools中的connections如果空闲超过8小时,Mysql将其断开,而C3P0并不知道该connection已经失效,如果这时有Client请求connection,C3P0将该失效的Connection提供给Client,将会造成上面的异常。 **nutz配置解决方案:** myapp.properties信息 db-driver=com.mysql.jdbc.Driver db-url=jdbc:mysql://localhost:3306/mydb?useUnicode=true&characterEncoding=UTF-8 db-username=mytest db-password=123456 core.js信息 var ioc = \{ config : \{ type : "org.nutz.ioc.impl.PropertiesProxy", fields : \{ paths : \["/conf/myapp.properties"\] \} \}, dataSource : \{ type :"com.mchange.v2.c3p0.ComboPooledDataSource", events : \{ depose :"close" \}, fields : \{ driverClass : \{java :"$config.get('db-driver')"\}, jdbcUrl : \{java :"$config.get('db-url')"\}, user : \{java :"$config.get('db-username')"\}, password : \{java :"$config.get('db-password')"\}, minPoolSize : 5, initialPoolSize : 10, maxPoolSize : 100, testConnectionOnCheckin : true, automaticTestTable : "C3P0TestTable", -- 这些是针对MySQLNonTransientConnectionException新加的属性 idleConnectionTestPeriod : 18000, maxIdleTime : 300, maxStatements : 0, --防止c3p0 APPARENT DEADLOCK的问题 numHelperThreads : 5 --防止c3p0 APPARENT DEADLOCK的问题 \} \}, // Dao dao : \{ type :'com.test.my.TestDao', args : \[ \{refer :"dataSource"\}\] \} \}; com.test.my.TestDao 类,该类直接继承了NutDao ,如果非必要,那么type里面可以直接写NutDao 。 public class TestDao extends NutDao \{ public TestDao () \{ super(); // TODO Auto-generated constructor stub \} public TestDao (DataSource dataSource, SqlManager sqlManager) \{ super(dataSource, sqlManager); // TODO Auto-generated constructor stub \} public TestDao (DataSource dataSource) \{ super(dataSource); // TODO Auto-generated constructor stub \} //下面是一些自己的方法 \} ## 解决方案 ## 解决的方法有3种: 1. 增加 wait\_timeout 的时间。 2. 减少 Connection pools 中 connection 的 lifetime。 3. 测试 Connection pools 中 connection 的有效性。 当然最好的办法是同时综合使用上述3种方法,下面就 DBCP、C3P0 和 simple jdbc dataSource 分别做一说明,假设 wait\_timeout 为默认的8小时 ### DBCP 增加以下配置信息: ### validationQuery = "select 1" testWhileIdle = "true" //some positive integer timeBetweenEvictionRunsMillis = 3600000 //set to something smaller than 'wait_timeout' minEvictableIdleTimeMillis = 18000000 //if you don't mind a hit for every getConnection(), set to "true" testOnBorrow = "true" ### C3P0 增加以下配置信息: ### //获取connnection时测试是否有效 testConnectionOnCheckin = true //自动测试的table名称 automaticTestTable=C3P0TestTable //set to something much less than wait_timeout, prevents connections from going stale idleConnectionTestPeriod = 18000 //set to something slightly less than wait_timeout, preventing 'stale' connections from being handed out maxIdleTime = 25000 //if you can take the performance 'hit', set to "true" testConnectionOnCheckout = true ### simple jdbc dataSource 增加以下配置信息: ### Pool.PingQuery = select 1 Pool.PingEnabled = true Pool.PingConnectionsOlderThan = 0 //对于空闲的连接一个小时检查一次 Pool.PingConnectionsNotUsedFor = 3600000 ## 其他方案(不推荐) ## 对于 MySQL5 之前的版本,如 Mysql4.x,只需要修改连接池配置中的 URL,添加一个参数:autoReconnect=true(如jdbc:mysql://hostaddress:3306/schemaname?autoReconnect=true),如果是 MySQL5 及以后的版本,则需要修改 my.cnf(或者my.ini) 文件,在 \[mysqld\] 后面添加上: <table style="border:1px solid silver; width:1280px; border-collapse:collapse; margin:0px!important; padding:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; font-size:12px!important; min-height:inherit!important"> <tbody style="margin:0px!important; padding:0px!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:inherit!important"> <tr style="margin:0px!important; padding:0px!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:inherit!important"> <td style="padding:3px; border:1px solid silver; border-collapse:collapse; margin:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; min-height:inherit!important"> <div style="margin:0px!important; padding:0px!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.1em!important; outline:0px!important; overflow:visible!important; position:relative!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:inherit!important"> <div style="margin:0px!important; padding:0px 1em 0px 0px!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.8em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:inherit!important; background-color:rgb(244,244,244)!important"> <code style="white-space:pre-wrap; margin:0px!important; padding:0px!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.8em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; min-height:inherit!important">wait_timeout = n</code> </div> <div style="margin:0px!important; padding:0px 1em 0px 0px!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.8em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; min-height:inherit!important"> <code style="white-space:pre-wrap; margin:0px!important; padding:0px!important; border:0px!important; bottom:auto!important; float:none!important; height:auto!important; left:auto!important; line-height:1.8em!important; outline:0px!important; overflow:visible!important; position:static!important; right:auto!important; top:auto!important; vertical-align:baseline!important; width:auto!important; font-family:Consolas,'Bitstream Vera Sans Mono','Courier New',Courier,monospace!important; min-height:inherit!important">interactive-timeout = n</code> </div> </div> </td> </tr> </tbody> </table> 其中 n 为服务器关闭交互式连接前等待活动的秒数。可是就部署而言每次修改 my.ini 比较麻烦,而且 n 等于多少才是合适的值呢? 所以并不推荐这个解决办法。) [c3p0详细配置][c3p0] **官方文档 :** [**http://www.mchange.com/projects/c3p0/index.html**][http_www.mchange.com_projects_c3p0_index.html] <c3p0-config> <default-config> <!--当连接池中的连接耗尽的时候c3p0一次同时获取的连接数。Default: 3 --> <property name="acquireIncrement">3</property> <!--定义在从数据库获取新连接失败后重复尝试的次数。Default: 30 --> <property name="acquireRetryAttempts">30</property> <!--两次连接中间隔时间,单位毫秒。Default: 1000 --> <property name="acquireRetryDelay">1000</property> <!--连接关闭时默认将所有未提交的操作回滚。Default: false --> <property name="autoCommitOnClose">false</property> <!--c3p0将建一张名为Test的空表,并使用其自带的查询语句进行测试。如果定义了这个参数那么 属性preferredTestQuery将被忽略。你不能在这张Test表上进行任何操作,它将只供c3p0测试 使用。Default: null--> <property name="automaticTestTable">Test</property> <!--获取连接失败将会引起所有等待连接池来获取连接的线程抛出异常。但是数据源仍有效 保留,并在下次调用getConnection()的时候继续尝试获取连接。如果设为true,那么在尝试 获取连接失败后该数据源将申明已断开并永久关闭。Default: false--> <property name="breakAfterAcquireFailure ">false</property> <!--当连接池用完时客户端调用getConnection()后等待获取新连接的时间,超时后将抛出 SQLException,如设为0则无限期等待。单位毫秒。Default: 0 --> <property name="checkoutTimeout">100</property> <!--通过实现ConnectionTester或QueryConnectionTester的类来 测试连接。类名需制定全路径。 Default: com.mchange.v2.c3p0.impl.DefaultConnectionTester--> <property name="connectionTesterClassNam e"></property> <!--指定c3p0 libraries的路径,如果(通常都是这样)在本地即可获得那么无需设置,默认null即可 Default: null--> <property name="factoryClassLocation">null</property> <!--Strongly disrecommended. Setting this to true may lead to subtle and bizarre bugs. (文档原文)作者强烈建议不使用的一个属性--> <property name="forceIgnoreUnresolvedTra nsactions">false</property> <!--每60秒检查所有连接池中的空闲连接。Default: 0 --> <property name="idleConnectionTestPeriod ">60</property> <!--初始化时获取三个连接,取值应在minPoolSize与maxPoolSize之间。Default: 3 --> <property name="initialPoolSize">3</property> <!--最大空闲时间,60秒内未使用则连接被丢弃。若为0则永不丢弃。Default: 0 --> <property name="maxIdleTime">60</property> <!--连接池中保留的最大连接数。Default: 15 --> <property name="maxPoolSize">15</property> <!--JDBC的标准参数,用以控制数据源内加载的PreparedStatements数量。但由于预缓存的statements 属于单个connection而不是整个连接池。所以设置这个参数需要考虑到多方面的因素。 如果maxStatements与maxStatementsPerConnection均为0,则缓存被关闭。Default: 0--> <property name="maxStatements">100</property> <!--maxStatementsPerConnection定义了连接池内单个连接所拥有的最大缓存statements数。Default: 0 --> <property name="maxStatementsPerConnecti on"></property> <!--c3p0是异步操作的,缓慢的JDBC操作通过帮助进程完成。扩展这些操作可以有效的提升性能 通过多线程实现多个操作同时被执行。Default: 3--> <property name="numHelperThreads">3</property> <!--当用户调用getConnection()时使root用户成为去获取连接的用户。主要用于连接池连接非c3p0 的数据源时。Default: null--> <property name="overrideDefaultUser">root</property> <!--与overrideDefaultUser参数对应使用的一个参数。Default: null--> <property name="overrideDefaultPassword">password</property> <!--密码。Default: null--> <property name="password"></property> <!--定义所有连接测试都执行的测试语句。在使用连接测试的情况下这个一显著提高测试速度。注意: 测试的表必须在初始数据源的时候就存在。Default: null--> <property name="preferredTestQuery">select id from test where id=1</property> <!--用户修改系统配置参数执行前最多等待300秒。Default: 300 --> <property name="propertyCycle">300</property> <!--因性能消耗大请只在需要的时候使用它。如果设为true那么在每个connection提交的 时候都将校验其有效性。建议使用idleConnectionTestPeriod或automaticTestTable 等方法来提升连接测试的性能。Default: false --> <property name="testConnectionOnCheckout ">false</property> <!--如果设为true那么在取得连接的同时将校验连接的有效性。Default: false --> <property name="testConnectionOnCheckin">true</property> <!--用户名。Default: null--> <property name="user">root</property> <!--早期的c3p0版本对JDBC接口采用动态反射代理。在早期版本用途广泛的情况下这个参数 允许用户恢复到动态反射代理以解决不稳定的故障。最新的非反射代理更快并且已经开始 广泛的被使用,所以这个参数未必有用。现在原先的动态反射与新的非反射代理同时受到 支持,但今后可能的版本可能不支持动态反射代理。Default: false--> <property name="usesTraditionalReflectiv eProxies">false</property> <property name="automaticTestTable">con\_test</property> <property name="checkoutTimeout">30000</property> <property name="idleConnectionTestPeriod ">30</property> <property name="initialPoolSize">10</property> <property name="maxIdleTime">30</property> <property name="maxPoolSize">25</property> <property name="minPoolSize">10</property> <property name="maxStatements">0</property> <user-overrides user="swaldman"> </user-overrides> </default-config> <named-config name="dumbTestConfig"> <property name="maxStatements">200</property> <user-overrides user="poop"> <property name="maxStatements">300</property> </user-overrides> </named-config> </c3p0-config> 参考: http://www.blogjava.net/Alpha/archive/2009/03/29/262789.html http://blog.csdn.net/bedweather/article/details/6743951 http://www.cnblogs.com/hemingwang0902/archive/2012/03/15/2397620.html http://blog.sina.com.cn/s/blog\_53b58e7c010197bj.html [c3p0]: http://www.blogjava.net/Alpha/archive/2009/03/29/262789.html [http_www.mchange.com_projects_c3p0_index.html]: http://www.mchange.com/projects/c3p0/index.html
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