我正在尝试为用户获取一些数据。当数据量约为 5000 行时，代码可以完美运行。但是，当我尝试获取大小为 25000 + 行的数据时，应用程序崩溃，并出现以下 StackTrace 异常:
org.springframework.transaction.CannotCreateTransactionException: Could not open Hibernate Session for transaction; nested exception is org.hibernate.exception.JDBCConnectionException: Cannot open connection
Caused by: org.hibernate.exception.JDBCConnectionException: Cannot open connection
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:74)
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:516)
at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:315)
at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:234)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:93)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:170)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:209)
at $Proxy1.getAggregatedFeaturesByCode(Unknown Source)
at com.ilrn.session.permissions.PermissionManagerImpl.handleFeatureGroup(PermissionManagerImpl.java:164)
at com.ilrn.session.permissions.PermissionManagerImpl.buildUserPermissionMap(PermissionManagerImpl.java:142)
at com.ilrn.entity.sql.SqlUser.getUserPermissions(SqlUser.java:2720)
at com.ilrn.controller.modules.UsersReport.addResults(UsersReport.java:384)
at com.ilrn.controller.modules.UsersReport.gen_main(UsersReport.java:229)
at com.ilrn.controller.modules.UsersReport.generate(UsersReport.java:156)
at com.ilrn.controller.ShellModule.generateShell(ShellModule.java:2016)
at com.ilrn.controller.Application.processRequest(Application.java:1462)
at com.ilrn.controller.BCAServlet.performTask(BCAServlet.java:197)
at com.ilrn.controller.BCAServlet.doPost(BCAServlet.java:172)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
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 com.ilrn.session.webservices.axisws.clientactivity.ForceResponseCode200Filter.doFilter(ForceResponseCode200Filter.java:24)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.ilrn.util.RequestDumperFilter.doFilter(RequestDumperFilter.java:273)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.ilrn.controller.filters.ReferenceFilter.doFilter(ReferenceFilter.java:57)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.ilrn.controller.filters.WebContextFilter.doFilter(WebContextFilter.java:60)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:202)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:173)
at com.ilrn.util.DynamicRequestsFilter.doFilter(DynamicRequestsFilter.java:113)
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: com.mysql.jdbc.CommunicationsException: The driver was unable to create a connection due to an inability to establish the client portion of a socket.
This is usually caused by a limit on the number of sockets imposed by the operating system. This limit is usually configurable.
For Unix-based platforms, see the manual page for the 'ulimit' command. Kernel or system reconfiguration may also be required.
For Windows-based platforms, see Microsoft Knowledge Base Article 196271 (Q196271).
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1112)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:344)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2332)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2369)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:377)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
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:241)
at org.springframework.orm.hibernate3.LocalDataSourceConnectionProvider.getConnection(LocalDataSourceConnectionProvider.java:81)
at org.hibernate.jdbc.ConnectionManager.openConnection(ConnectionManager.java:417)
... 56 more
Caused by: java.net.BindException: Address already in use: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:364)
at java.net.Socket.connect(Socket.java:507)
at java.net.Socket.connect(Socket.java:457)
at java.net.Socket.<init>(Socket.java:365)
at java.net.Socket.<init>(Socket.java:207)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:257)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:294)
... 70 more
我有一点线索表明应用程序正在尝试建立多个连接并超出连接数限制？ 我是否需要按照堆栈跟踪本身的建议增加此限制
这通常是由操作系统对套接字数量的限制引起的。此限制通常是可配置的。
如果是这样，该怎么做？ 任何帮助将不胜感激。
最佳答案
增加连接池的最大大小，并使用批量更新:
设置批量大小
hibernate.jdbc.batch_size 20
批量更新将是这样的:
Session session = sessionFactory.openSession();
Transaction tx = session.beginTransaction();
ScrollableResults customers = session.getNamedQuery("GetCustomers")
.setCacheMode(CacheMode.IGNORE)
.scroll(ScrollMode.FORWARD_ONLY);
int count=0;
while ( customers.next() ) {
Customer customer = (Customer) customers.get(0);
customer.updateStuff(...);
if ( ++count % 20 == 0 ) {
//flush a batch of updates and release memory:
session.flush();
session.clear();
}
}
tx.commit();
session.close();
reference here 。如果你仍然遇到同样的问题，请发布你的c3p0配置，也许那里有问题。
关于java - 从mysql获取大数据时出现连接异常，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/18014539/