是在SSH三大框架整合时出现的错误，已经被这个问题困扰几天了，老师布置这个项目做练习，可是刚开始部署环境就报出这个错误:
windows 8的系统，myeclipse已经降到了10.7版，tomcat是7.0.64，数据库是oracle 11g R2 版，之前已经失败过的
版本有：windows 10+myeclipse2015 ci/myeclipse 2014 GA+tomcat 8.0.14，
在网上搜索的其他问题乍看跟我的一样，仔细看会发现根本不一样，因此也试过其他的解决办法，比如更改maxPoolSize什么的，比如更换ojdbc，等等，各种方式都试过了，这个错误还是在那里。下面是错误代码，我只粘贴最关键的（第一次在csdn提问，有什么潜规则吗？大神可以指出来，新人唯一不怕的就是错误和被指出错误）：
2015-10-4 1:34:30 org.apache.catalina.core.ApplicationContext log
信息: Initializing Spring root WebApplicationContext
01:34:34,407 ERROR JDBCExceptionReporter:101 - An attempt by a client to checkout a Connection has timed out.
01:34:36,725 ERROR JDBCExceptionReporter:101 - An attempt by a client to checkout a Connection has timed out.
01:34:36,727 ERROR SchemaUpdate:175 - could not get database metadata
java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:65)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:527)
...
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:441)
at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:303)
at java.util.concurrent.FutureTask.run(FutureTask.java:138)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:619)
Caused by: com.mchange.v2.resourcepool.TimeoutException: A client timed out while waiting to acquire a resource from com.mchange.v2.resourcepool.BasicResourcePool@31930611 -- timeout at awaitAvailable()
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1317)
at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)
at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)
... 38 more
01:34:36,727 ERROR SchemaUpdate:222 - could not complete schema update
java.sql.SQLException: An attempt by a client to checkout a Connection has timed out.
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:106)
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:65)
...
at java.lang.Thread.run(Thread.java:619)
Caused by: com.mchange.v2.resourcepool.TimeoutException: A client timed out while waiting to acquire a resource from com.mchange.v2.resourcepool.BasicResourcePool@31930611 -- timeout at awaitAvailable()
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1317)
at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:557)
at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:477)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:525)
... 38 more
