电脑发生了错误，求助

进一个网站时显示出来：请问为什么？怎么办？ 系统异常

对不起，系统在处理数据时发生了异常！ 异常信息： Could not open Hibernate Session for transaction; nested exception is org.hibernate.exception.GenericJDBCException: Cannot open connection 您可以重新整理数据再次尝试该操作。 查看详细错误 返回上一步 org.springframework.transaction.CannotCreateTransactionException: Could not open Hibernate Session for transaction; nested exception is org.hibernate.exception.GenericJDBCException: Cannot open connection Caused by: org.hibernate.exception.GenericJDBCException: Cannot open connection at org.hibernate.exception.SQLStateConverter.handledNonSpecificException(SQLStateConverter.java:103) at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:91) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43) at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:29) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:420) at org.hibernate.jdbc.ConnectionManager.getConnection(ConnectionManager.java:144) at org.hibernate.jdbc.JDBCContext.connection(JDBCContext.java:129) at org.hibernate.transaction.JDBCTransaction.begin(JDBCTransaction.java:57) at org.hibernate.impl.SessionImpl.beginTransaction(SessionImpl.java:1290) at org.springframework.orm.hibernate3.HibernateTransactionManager.doBegin(HibernateTransactionManager.java:494) at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:315) at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:257) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:102) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:209) at $Proxy54.listNoticeForUser(Unknown Source) at arts.web.IndexPageAction.onShowDetail(IndexPageAction.java:142) at common.web.GenericDAOAction.onAction(GenericDAOAction.java:126) at common.web.GenericDAOAction.showForm(GenericDAOAction.java:104) at org.springframework.web.servlet.mvc.AbstractFormController.showNewForm(AbstractFormController.java:323) at org.springframework.web.servlet.mvc.AbstractFormController.handleRequestInternal(AbstractFormController.java:263) at org.springframework.web.servlet.mvc.AbstractController.handleRequest(AbstractController.java:153) at org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter.handle(SimpleControllerHandlerAdapter.java:45) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:806) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:736) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:396) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:350) at javax.servlet.http.HttpServlet.service(HttpServlet.java:689) at javax.servlet.http.HttpServlet.service(HttpServlet.java:802) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:252) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.springframework.orm.hibernate3.support.OpenSessionInViewFilter.doFilterInternal(OpenSessionInViewFilter.java:174) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:77) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:78) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:77) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at cn.pconline.common.monitor.MonitorFilter.doFilter(MonitorFilter.java:79) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:213) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:178) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:126) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:105) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:107) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:148) at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:856) at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.processConnection(Http11Protocol.java:744) at org.apache.tomcat.util.net.PoolTcpEndpoint.processSocket(PoolTcpEndpoint.java:527) at org.apache.tomcat.util.net.LeaderFollowerWorkerThread.runIt(LeaderFollowerWorkerThread.java:80) at org.apache.tomcat.util.threads.ThreadPool$ControlRunnable.run(ThreadPool.java:684) at java.lang.Thread.run(Thread.java:595) Caused by: java.sql.SQLException: Couldn't get connection because we are at maximum connection count (200/200) and there are none available at org.logicalcobwebs.proxool.Prototyper.quickRefuse(Prototyper.java:309) at org.logicalcobwebs.proxool.ConnectionPool.getConnection(ConnectionPool.java:152) at org.logicalcobwebs.proxool.ProxoolDriver.connect(ProxoolDriver.java:89) at java.sql.DriverManager.getConnection(DriverManager.java:525) at java.sql.DriverManager.getConnection(DriverManager.java:140) at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:291) at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:277) at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:259) at org.springframework.jdbc.datasource.DriverManagerDataSource.getConnection(DriverManagerDataSource.java:240) at org.springframework.orm.hibernate3.LocalDataSourceConnectionProvider.getConnection(LocalDataSourceConnectionProvider.java:81) at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:417) ... 49 more

如果用Hibernate与数据库 Microsoft SQLServer 2000组合，在取子表集合的时候会抛出异常:
org.hibernate.exception.GenericJDBCException: could not initialize a collection:
和异常:SQL Server 2000 Driver for JDBC ResultSet can not re-read row data for column 1
这是因为微软的Microsoft SQLServer驱动有以下问题:
1、如果采用jdbc-odbc驱动，那么就必须按照查询顺序来一次读取（不论有没有image或text类型）

2、如果采用微软提供的ms sql server jdbc driver，如果查询语句中，不存在image或text类型字段，那么可以按照无序获取

3、如果采用微软提供的ms sql server jdbc driver，如果查询语句中，存在image或text类型字段，那么就必须按照顺序读取，否则就会报告Driver]ResultSet can not re-read row data for column之类的错误

4、如果想不查询语句中有没有image或text类型字段，都可以不按照顺序获取，或重复获取。
Hibernate在取子表集合时，它的不是按查询顺序来一次读取的，所以会抛出上述异常.
解决办法:
更换Microsoft SQLServer驱动，我现在用的是jtds-1.2.jar,这个驱动包大家可以到CSDN下载.
它的连接字符串是:jdbc:jtds:sqlserver://localhost:1433;DatabaseName=数据库名
驱动类:net.sourceforge.jtds.jdbc.Driver,