我有一个java应用程序，我想创建池连接。我在Jboss AS 7.0.2上使用Hibernate 4.0_final和c3p0，MySQL
hibernate.cfg.xml中：
<hibernate-configuration>
<session-factory >
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test</property>
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password"></property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>
<property name="hibernate.show_sql">true</property>
<property name="hibernate.c3p0.acquire_increment">1</property>
<property name="hibernate.c3p0.idle_test_period">100</property>
<property name="hibernate.c3p0.max_size">100</property>
<property name="hibernate.c3p0.max_statements">0</property>
<property name="hibernate.c3p0.min_size">5</property>
<property name="hibernate.c3p0.timeout">30</property>
<!-- <property name="hibernate.connection.provider_class">org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider</property> -->
<mapping class="com.test.Test"/>
c3p0.properties：
c3p0.testConnectionOnCheckout=true
c3p0.acquireRetryDelay=1000
c3p0.acquireRetryAttempts=1
我从中获得Session的课程，用于处理数据库
public class HibernateSessionFactory {
private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";
private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
private static org.hibernate.cfg.Configuration configuration = new org.hibernate.cfg.AnnotationConfiguration();
private static org.hibernate.SessionFactory sessionFactory;
private static String configFile = CONFIG_FILE_LOCATION;
static {
rebuildSessionFactory();
}
public static Session getSession() throws HibernateException {
Session session = (Session) threadLocal.get();
if (session == null || !session.isOpen()) {
if (sessionFactory == null) {
rebuildSessionFactory();
}
session = (sessionFactory != null) ? sessionFactory.openSession(): null;
threadLocal.set(session);
}
return session;
}
public static void rebuildSessionFactory() {
try {
configuration.configure(configFile);
sessionFactory = configuration.buildSessionFactory();
} catch (Exception e) {
e.printStackTrace();
}
}
}
创建SessionFactory后，我在MySQL_WorkBench中看到了与我的数据库的5个连接。之后，我发送请求并等待50秒（在MySql_Server中wait_timeout，我设置为测试）。 在Workbench中，我看到已经打开4连接。我发送了请求并收到错误，但在工作台中我看到已经有5个连接。
错误：
org.hibernate.exception.JDBCConnectionException: No operations allowed after connection closed.
org.hibernate.exception.internal.SQLStateConverter.convert(SQLStateConverter.java:107)
org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:125)
org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:110)
org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.continueInvocation(ConnectionProxyHandler.java:146)
org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
$Proxy18.prepareStatement(Unknown Source)
org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:147)
org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:166)
org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:145)
org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1739)
org.hibernate.loader.Loader.doQuery(Loader.java:828)
org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:289)
org.hibernate.loader.Loader.doList(Loader.java:2463)
org.hibernate.loader.Loader.doList(Loader.java:2449)
org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2279)
org.hibernate.loader.Loader.list(Loader.java:2274)
org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:470)
org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:355)
org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:196)
org.hibernate.internal.SessionImpl.list(SessionImpl.java:1115)
org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
org.hibernate.internal.AbstractQueryImpl.uniqueResult(AbstractQueryImpl.java:890)
com.test.dao.UserDAO.getTimeLastActivity(UserDAO.java:150)
com.test.servlets.PostFilter.doFilter(PostFilter.java:75)
com.test.servlets.PathFilter.doFilter(PathFilter.java:57)
root cause
com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.lang.reflect.Constructor.newInstance(Constructor.java:525)
com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
com.mysql.jdbc.Util.getInstance(Util.java:386)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:1013)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:987)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:982)
com.mysql.jdbc.SQLError.createSQLException(SQLError.java:927)
com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1205)
com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1197)
com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4186)
com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4152)
com.mchange.v2.c3p0.impl.NewProxyConnection.prepareStatement(NewProxyConnection.java:213)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.hibernate.engine.jdbc.internal.proxy.ConnectionProxyHandler.continueInvocation(ConnectionProxyHandler.java:138)
org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
$Proxy18.prepareStatement(Unknown Source)
org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:147)
org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:166)
org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:145)
org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1739)
org.hibernate.loader.Loader.doQuery(Loader.java:828)
org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:289)
org.hibernate.loader.Loader.doList(Loader.java:2463)
org.hibernate.loader.Loader.doList(Loader.java:2449)
org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2279)
org.hibernate.loader.Loader.list(Loader.java:2274)
org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:470)
org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:355)
org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:196)
org.hibernate.internal.SessionImpl.list(SessionImpl.java:1115)
org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
org.hibernate.internal.AbstractQueryImpl.uniqueResult(AbstractQueryImpl.java:890)
com.test.dao.UserDAO.getTimeLastActivity(UserDAO.java:150)
com.test.servlets.PostFilter.doFilter(PostFilter.java:75)
com.test.servlets.PathFilter.doFilter(PathFilter.java:57)
root cause
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 96 189 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago.
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.lang.reflect.Constructor.newInstance(Constructor.java:525)
com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3102)
com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2991)
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3532)
com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2002)
com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2624)
com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2127)
com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2293)
com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:76)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:122)
org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
$Proxy19.executeQuery(Unknown Source)
org.hibernate.loader.Loader.getResultSet(Loader.java:1978)
org.hibernate.loader.Loader.doQuery(Loader.java:829)
org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:289)
org.hibernate.loader.Loader.doList(Loader.java:2463)
org.hibernate.loader.Loader.doList(Loader.java:2449)
org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2279)
org.hibernate.loader.Loader.list(Loader.java:2274)
org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:470)
org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:355)
org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:196)
org.hibernate.internal.SessionImpl.list(SessionImpl.java:1115)
org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
org.hibernate.internal.AbstractQueryImpl.uniqueResult(AbstractQueryImpl.java:890)
com.test.dao.UserDAO.getTimeLastActivity(UserDAO.java:150)
com.test.servlets.PostFilter.doFilter(PostFilter.java:75)
com.test.servlets.PathFilter.doFilter(PathFilter.java:57)
root cause
java.net.SocketException: Software caused connection abort: recv failed
java.net.SocketInputStream.socketRead0(Native Method)
java.net.SocketInputStream.read(SocketInputStream.java:150)
java.net.SocketInputStream.read(SocketInputStream.java:121)
com.mysql.jdbc.util.ReadAheadInputStream.fill(ReadAheadInputStream.java:114)
com.mysql.jdbc.util.ReadAheadInputStream.readFromUnderlyingStreamIfNecessary(ReadAheadInputStream.java:161)
com.mysql.jdbc.util.ReadAheadInputStream.read(ReadAheadInputStream.java:189)
com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2549)
com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3002)
com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:2991)
com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3532)
com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2002)
com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2163)
com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2624)
com.mysql.jdbc.PreparedStatement.executeInternal(PreparedStatement.java:2127)
com.mysql.jdbc.PreparedStatement.executeQuery(PreparedStatement.java:2293)
com.mchange.v2.c3p0.impl.NewProxyPreparedStatement.executeQuery(NewProxyPreparedStatement.java:76)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:601)
org.hibernate.engine.jdbc.internal.proxy.AbstractStatementProxyHandler.continueInvocation(AbstractStatementProxyHandler.java:122)
org.hibernate.engine.jdbc.internal.proxy.AbstractProxyHandler.invoke(AbstractProxyHandler.java:81)
$Proxy19.executeQuery(Unknown Source)
org.hibernate.loader.Loader.getResultSet(Loader.java:1978)
org.hibernate.loader.Loader.doQuery(Loader.java:829)
org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:289)
org.hibernate.loader.Loader.doList(Loader.java:2463)
org.hibernate.loader.Loader.doList(Loader.java:2449)
org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2279)
org.hibernate.loader.Loader.list(Loader.java:2274)
org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:470)
org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:355)
org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:196)
org.hibernate.internal.SessionImpl.list(SessionImpl.java:1115)
org.hibernate.internal.QueryImpl.list(QueryImpl.java:101)
org.hibernate.internal.AbstractQueryImpl.uniqueResult(AbstractQueryImpl.java:890)
com.test.dao.UserDAO.getTimeLastActivity(UserDAO.java:150)
com.test.servlets.PostFilter.doFilter(PostFilter.java:75)
com.test.servlets.PathFilter.doFilter(PathFilter.java:57)
如何解决这个问题？
答案 0 :(得分：3)
我遇到过这样的问题，我从服务器日志中得到了解决方案。
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was56936 milliseconds ago.The last packet sent successfully to the server was 56936 milliseconds ago,
which is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts,
or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
尝试将连接网址设置为：
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/test?autoReconnect=true</property>
但是在使用任何交易存储引擎时，他们不推荐使用它。
答案 1 :(得分：1)
尝试通过将此添加到my.cnf来增加超时：
[mysqld]
interactive_timeout=864000
wait_timeout=864000