采用c3p0连接池，每次调试程序，第一次访问时（Tomcat服务器重启后再访问）都会出现以下错误，然后连接库需要很长时间，最终是可以连上的，之后再访问就没问题了，请高手们会诊一下，希望能帮小弟解决此问题，不胜感激！
2009-9-27 13:32:26 com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector run
警告: com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@1c5d81c -- APPARENT DEADLOCK!!! Creating emergency threads for unassigned pending tasks!
2009-9-27 13:32:26 com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector run
警告: com.mchange.v2.async.ThreadPoolAsynchronousRunner$DeadlockDetector@1c5d81c -- APPARENT DEADLOCK!!! Complete Status:
Managed Threads: 3
Active Threads: 3
Active Tasks: com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@b7ad3 (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0)
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@1acdcb9 (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1)
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@1cf2ef6 (com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2)
Pending Tasks:
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@114382d
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@744a4d
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask@ba2b6b
Pool thread stack traces:
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#0,5,main]
com.mysql.jdbc.MysqlIO.scanForAndThrowDataTruncation(MysqlIO.java:3685)
com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2227)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2536)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2465)
com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1383)
com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:3777)
com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3348)
com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2045)
com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:718)
com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
java.lang.reflect.Constructor.newInstance(Constructor.java:513)
com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#1,5,main]
java.lang.Class.forName0(Native Method)
java.lang.Class.forName(Class.java:169)
com.mysql.jdbc.SQLError.<clinit>(SQLError.java:154)
com.mysql.jdbc.MysqlIO.scanForAndThrowDataTruncation(MysqlIO.java:3685)
com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2227)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2536)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2465)
com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1383)
com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:3777)
com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3348)
com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2045)
com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:718)
com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
java.lang.reflect.Constructor.newInstance(Constructor.java:513)
com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
Thread[com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread-#2,5,main]
com.mysql.jdbc.MysqlIO.scanForAndThrowDataTruncation(MysqlIO.java:3685)
com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2227)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2536)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2465)
com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1383)
com.mysql.jdbc.ConnectionImpl.loadServerVariables(ConnectionImpl.java:3777)
com.mysql.jdbc.ConnectionImpl.initializePropsFromServer(ConnectionImpl.java:3348)
com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2045)
com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:718)
com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:39)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:27)
java.lang.reflect.Constructor.newInstance(Constructor.java:513)
com.mysql.jdbc.Util.handleNewInstance(Util.java:406)
com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:302)
com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:282)
com.mchange.v2.c3p0.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:134)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:182)
com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:171)
com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:137)
com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1014)
com.mchange.v2.resourcepool.BasicResourcePool.access$800(BasicResourcePool.java:32)
com.mchange.v2.resourcepool.BasicResourcePool$AcquireTask.run(BasicResourcePool.java:1810)
com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:547)
http://www.javaeye.com/topic/22160?page=3#142629
我也遇到这个问题
看下这个应该是c3p0的bug
<property name="hibernate.c3p0.max_statements">0</property>