调用session.close();后Connection对象为何还没有关闭？

[code:1]    Configuration cfg = new Configuration().addClass(Cat.class);   
       SessionFactory factory = cfg.buildSessionFactory();
       Session session = factory.openSession();
       Transaction tx = session.beginTransaction();
       Connection connection = session.connection();
      
       Cat cat1 = (Cat)session.load(Cat.class, CATID);
       cat1.setName("bbbbbbbbbbbbbbbb");      
       tx.commit();
       
       session.close();
      
       System.out.println("connection是否关闭："+connection.isClosed());[/code:1]

最后一行，打出的是 false.
       session.close();没有调用connection.close()吗？

如果你的Connection来自于连接池，他只不过被归还给池了，确实没有物理关闭，这是正常的结果。

3ks!

我使用的默认的hibernate.properties置于classpath下，
应该没有使用commons-pool或c3p9等第三方连接池，

请问：hibernate内部也默认使用自带的连接池？


[code:1]
######################
### Query Language ###
######################

## define query language constants / function names

hibernate.query.substitutions true 1, false 0, yes 'Y', no 'N'

## package imports

hibernate.query.imports net.sf.hibernate.test, net.sf.hibernate.eg



#################
### Platforms ###
#################

## JNDI Datasource

#hibernate.connection.datasource jdbc/test
#hibernate.connection.username db2
#hibernate.connection.password db2


## PostgreSQL

#hibernate.dialect net.sf.hibernate.dialect.PostgreSQLDialect
#hibernate.connection.driver_class org.postgresql.Driver
#hibernate.connection.url jdbc:postgresql:template1
#hibernate.connection.username pg
#hibernate.connection.password
#hibernate.query.substitutions yes 'Y', no 'N'


## DB2

hibernate.dialect net.sf.hibernate.dialect.DB2Dialect
hibernate.connection.driver_class com.p6spy.engine.spy.P6SpyDriver

hibernate.connection.url jdbc:db2//192.168.51.15/ebuy
hibernate.connection.username administrator
hibernate.connection.password inforflow


## MySQL

#hibernate.dialect net.sf.hibernate.dialect.MySQLDialect
#hibernate.connection.driver_class org.gjt.mm.mysql.Driver
#hibernate.connection.driver_class com.mysql.jdbc.Driver
#hibernate.connection.url jdbc:mysql://localhost/java?useUnicode=true&characterEncoding=GBK
#hibernate.connection.username root
#hibernate.connection.password kunmao


## Oracle

#hibernate.dialect net.sf.hibernate.dialect.OracleDialect
#hibernate.connection.driver_class oracle.jdbc.driver.OracleDriver
#hibernate.connection.username ora
#hibernate.connection.password ora
#hibernate.connection.url jdbc:oracle:thin:@localhost:1521:test


## Sybase

#hibernate.dialect net.sf.hibernate.dialect.SybaseDialect
#hibernate.connection.driver_class com.sybase.jdbc2.jdbc.SybDriver
#hibernate.connection.username sa
#hibernate.connection.password sasasa
#hibernate.connection.rl jdbc:sybase:Tds:co3061835-a:5000/tempdb


## HypersonicSQL

#hibernate.dialect net.sf.hibernate.dialect.HSQLDialect
#hibernate.connection.driver_class org.hsqldb.jdbcDriver
#hibernate.connection.username sa
#hibernate.connection.password
#hibernate.connection.url jdbc:hsqldb:hsql://localhost
#hibernate.connection.url jdbc:hsqldb:test


## Mckoi SQL

#hibernate.dialect net.sf.hibernate.dialect.MckoiDialect
#hibernate.connection.driver_class com.mckoi.JDBCDriver
#hibernate.connection.url jdbc:mckoi:///
#hibernate.connection.url jdbc:mckoi:local://C:/mckoi0.94h/db.conf
#hibernate.connection.username admin
#hibernate.connection.password nimda


## SAP DB

#hibernate.dialect net.sf.hibernate.dialect.SAPDBDialect
#hibernate.connection.driver_class com.sap.dbtech.jdbc.DriverSapDB
#hibernate.connection.url jdbc:sapdb://localhost/TST
#hibernate.connection.username TEST
#hibernate.connection.password TEST
#hibernate.query.substitutions yes 'Y', no 'N'


## MS SQL Server

#hibernate.dialect net.sf.hibernate.dialect.SybaseDialect
#hibernate.connection.username sa
#hibernate.connection.password

## JSQL Driver

#hibernate.connection.driver_class com.jnetdirect.jsql.JSQLDriver
#hibernate.connection.url jdbc:JSQLConnect://WL99LCX27

## JTURBO Driver

#hibernate.connection.driver_class com.newatlanta.jturbo.driver.Driver
#hibernate.connection.url jdbc:JTurbo://CO3061835-A:1433/master

## WebLogic Driver

#hibernate.connection.driver_class weblogic.jdbc.mssqlserver4.Driver
#hibernate.connection.url jdbc:weblogic:mssqlserver4:CO3061835-A:1433

## Microsoft Driver (not supported!)

#hibernate.connection.driver_class com.microsoft.jdbc.sqlserver.SQLServerDriver
#hibernate.connection.url jdbc:microsoft:sqlserver://CO3061835-A:1433;SelectMethod=cursor


## Interbase

#hibernate.dialect net.sf.hibernate.dialect.InterbaseDialect
#hibernate.connection.username sysdba
#hibernate.connection.password masterkey

## DO NOT specify hibernate.connection.sqlDialect

## InterClient

#hibernate.connection.driver_class interbase.interclient.Driver
#hibernate.connection.url jdbc:interbase://localhost:3060/C:/firebird/test.gdb

## Pure Java

#hibernate.connection.driver_class org.firebirdsql.jdbc.FBDriver
#hibernate.connection.url jdbc:firebirdsql:localhost/3050:/firebird/test.gdb


## Pointbase

#hibernate.dialect net.sf.hibernate.dialect.PointbaseDialect
#hibernate.connection.driver_class com.pointbase.jdbc.jdbcUniversalDriver
#hibernate.connection.url jdbc:pointbase:embedded:sample
#hibernate.connection.username PBPUBLIC
#hibernate.connection.password PBPUBLIC



#################################
### Hibernate Connection Pool ###
#################################

hibernate.connection.pool_size 1
hibernate.statement_cache.size 25



###########################
### C3P0 Connection Pool###
###########################

#hibernate.c3p0.max_size 2
#hibernate.c3p0.min_size 2
#hibernate.c3p0.timeout 5000
#hibernate.c3p0.max_statements 100
#hibernate.c3p0.validate false



###################################
### Apache DBCP Connection Pool ###
###################################

# connection pool

#hibernate.dbcp.maxActive 100
#hibernate.dbcp.whenExhaustedAction 1
#hibernate.dbcp.maxWait 120000
#hibernate.dbcp.maxIdle 10

## prepared statement cache

#hibernate.dbcp.ps.maxActive 100
#hibernate.dbcp.ps.whenExhaustedAction 1
#hibernate.dbcp.ps.maxWait 120000
#hibernate.dbcp.ps.maxIdle 100

# optional query to validate pooled connections:

#hibernate.dbcp.validationQuery select 1 from dual
#hibernate.dbcp.testOnBorrow true
#hibernate.dbcp.testOnReturn false


#################################
### Plugin ConnectionProvider ###
#################################

## use a custom ConnectionProvider (if not set, Hibernate will choose a built-in ConnectionProvider using hueristics)

#hibernate.connection.provider_class net.sf.hibernate.connection.DriverManagerConnectionProvider
#hibernate.connection.provider_class net.sf.hibernate.connection.DatasourceConnectionProvider
#hibernate.connection.provider_class net.sf.hibernate.connection.C3P0ConnectionProvider
#hibernate.connection.provider_class net.sf.hibernate.connection.DBCPConnectionProvider



#######################
### Transaction API ###
#######################

## the Transaction API abstracts application code from the underlying JTA or JDBC transactions

#hibernate.transaction.factory_class net.sf.hibernate.transaction.JTATransactionFactory
#hibernate.transaction.factory_class net.sf.hibernate.transaction.JDBCTransactionFactory


## to use JTATransactionFactory, Hibernate must be able to locate the UserTransaction in JNDI
## default is java:comp/UserTransaction

#jta.UserTransaction jta/usertransaction
#jta.UserTransaction javax.transaction.UserTransaction
#jta.UserTransaction UserTransaction


## to use JTATransactionFactory with JCS caching, Hibernate must be able to obtain the JTA TransactionManager

#hibernate.transaction.manager_lookup_class net.sf.hibernate.transaction.JBossTransactionManagerLookup
#hibernate.transaction.manager_lookup_class net.sf.hibernate.transaction.WeblogicTransactionManagerLookup
#hibernate.transaction.manager_lookup_class net.sf.hibernate.transaction.WebSphereTransactionManagerLookup
#hibernate.transaction.manager_lookup_class net.sf.hibernate.transaction.OrionTransactionManagerLookup
#hibernate.transaction.manager_lookup_class net.sf.hibernate.transaction.ResinTransactionManagerLookup



##############################
### Miscellaneous Settings ###
##############################

## print all generated SQL to the console

hibernate.show_sql true


## specify a JDBC isolation level

#hibernate.connection.isolation 4


## set the JDBC fetch size

#hibernate.jdbc.fetch_size 25


## set the maximum JDBC 2 batch size (a nonzero value enables batching)

hibernate.jdbc.batch_size 0


## enable use of JDBC 2 scrollable ResultSets (specifying a Dialect will cause Hibernate to use a sensible default)

#hibernate.jdbc.use_scrollable_resultset true


## use streams when writing binary types to / from JDBC

hibernate.jdbc.use_streams_for_binary true


## specify a default schema for unqualified tablenames

#hibernate.default_schema test


## use a custom stylesheet for XML generation (if not specified, hibernate-default.xslt will be used)

#hibernate.xml.output_stylesheet C:/Hibernate/net/sf/hibernate/hibernate-default.xslt


## enable outerjoin fetching (specifying a Dialect will cause Hibernate to use sensible default)

#hibernate.use_outer_join false


## enable CGLIB reflection optimizer (enabled by default)

#hibernate.cglib.use_reflection_optimizer false



############
### JNDI ###
############

## specify a JNDI name for the SessionFactory

#hibernate.session_factory_name hibernate/session_factory


## Hibernate uses JNDI to bind a name to a SessionFactory and to look up the JTA UserTransaction;
## if hibernate.jndi.* are not specified, Hibernate will use the default InitialContext() which
## is the best approach in an application server

#file system
#hibernate.jndi.class com.sun.jndi.fscontext.RefFSContextFactory
#hibernate.jndi.url file:/

#WebSphere
#hibernate.jndi.class com.ibm.websphere.naming.WsnInitialContextFactory
#hibernate.jndi.url iiop://localhost:900/
[/code:1]

另外请教一个与hibernate无关的问题，已困惑已久：

使用源自连接池的数据库连接对象connection,
若调用connection.close(),

此连接对象是关闭，
还是没有关闭，只返回给了连接池

跟踪了一下Hiberante代码

发现了默认的Pool?这是Hibernate自身提供的默认Connection Pool吗？
和其他第三方Pool什么区别？


[code:1]
package net.sf.hibernate.connection;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.Properties;

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.cfg.Environment;
import net.sf.hibernate.util.JDBCExceptionReporter;
import net.sf.hibernate.util.PropertiesHelper;
import net.sf.hibernate.util.ReflectHelper;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
* A connection provider that uses <tt>java.sql.DriverManager</tt>. This provider
* also implements a very rudimentary connection pool.
* @see ConnectionProvider
* @author Gavin King
*/
public class DriverManagerConnectionProvider implements ConnectionProvider
[/code:1]

Hibernate提供的连接池是一个非常简单的实现，开发的时候可以用用。

没有关闭，只返回给了连接池

那要看连接池的实现了。一般都是返回给连接池，因为新建连接的开销太大了。

呵呵，感觉楼上几位回答的还不是很彻底。

象这样的回答：“一般都是返回给连接池”

究竟是通过connection.close()方法返回给连接池，
还是另外的方法，如追加到池中。

Hibernate实现的池源代码你不都已经看过了吗？还需要问？