ConnectionProviderFactory 使用那种“连接池”
hibernate提供org.hibernate.connection.ConnectionProvider获取jdbc连接，ConnectionProvider实现类包括 DriverManagerConnectionProvider DateSourceConnectionProvider UserSuppliedConnectionProvider C3P0ConnectionProvider,ProxoolConnectionProvider 简要说说这些实现 DriverManagerConnectionProvider用List维护连接，当jvm调用finalize方法时，关闭掉集合中的所有连接，并清空集合 getConnection 如果集合中有,则拿到最新的那个连接；如果没有，DriverManager获取连接 closeConnection 如果集合中连接的数量已经等于配置中指定的poolSize，则关闭此连接；如果没有则放入集合 下 DateSourceManagerConnectionProvider通过jndi查找数据源配置中的hibernate.jndi.class和hibernate.jndi.url用于初始化javax.naming.InitialContext常用jndi配置hibernate.connection.datasource指定数据源的名称 getConnection 通过javax.sql.DataSource,getConnection获取 closeConnection java.sql.Connection.close C3P0ConnectionProvider使用c3p0实现的javax.sql.DataSourcec3p0 ProxoolConnectionProvider使用proxool实现proxool UserSuppliedConnectionProvider用户继承此类实现自己的连接提供者 至于使用哪种，由org.hibernate.connection.ConnectionProviderFactory.newConnectionProvider决定 newConnectionProvider描述如下 如果hibernate.connection.provider_class不为空，使用实例化后的类 如果发现hibernate.connection.datasource，使用DatesourceConnectionProvider 如果发现hibernate.c3p0.*,使用C3P0ConnectionProvider 如果发现hibernate.proxool，使用ProxoolConnectionProvider 如果发现hibernate.connection.url，使用DriverManagerConnectionProvider 否则，返回UserSuppliedConnectionProvider//$Id: ConnectionProviderFactory.java 7541 2005-07-18 22:37:31Z epbernard $package org.hibernate.connection;import java.util.HashSet;import java.util.Iterator;import java.util.Properties;import java.util.Set;import java.util.Map;import java.beans.Introspector;import java.beans.BeanInfo;import java.beans.IntrospectionException;import java.beans.PropertyDescriptor;import java.lang.reflect.Method;import java.lang.reflect.InvocationTargetException;import org.apache.commons.logging.Log;import org.apache.commons.logging.LogFactory;import org.hibernate.HibernateException;import org.hibernate.cfg.Environment;import org.hibernate.util.ReflectHelper;/** * Instantiates a connection provider given either <tt>System</tt> properties or * a <tt>java.util.Properties</tt> instance. The <tt>ConnectionProviderFactory</tt> * first attempts to find a name of a <tt>ConnectionProvider</tt> subclass in the * property <tt>hibernate.connection.provider_class</tt>. If missing, heuristics are used * to choose either <tt>DriverManagerConnectionProvider</tt>, * <tt>DatasourceConnectionProvider</tt>, <tt>C3P0ConnectionProvider</tt> or * <tt>DBCPConnectionProvider</tt>. * @see ConnectionProvider * @author Gavin King */public final class ConnectionProviderFactory {private static final Log log = LogFactory.getLog(ConnectionProviderFactory.class);/** * Instantiate a <tt>ConnectionProvider</tt> using <tt>System</tt> properties. * @return ConnectionProvider * @throws HibernateException */public static ConnectionProvider newConnectionProvider() throws HibernateException {return newConnectionProvider( Environment.getProperties() );}/** * Instantiate a <tt>ConnectionProvider</tt> using given properties. * Method newConnectionProvider. * @param properties hibernate <tt>SessionFactory</tt> properties * @return ConnectionProvider * @throws HibernateException */public static ConnectionProvider newConnectionProvider(Properties properties) throws HibernateException {return newConnectionProvider( properties, null );}/** * Instantiate a <tt>ConnectionProvider</tt> using given properties. * Method newConnectionProvider. * @param properties hibernate <tt>SessionFactory</tt> properties * @Param connectionProviderInjectionData object to be injected in the conenction provided * @return ConnectionProvider * @throws HibernateException */public static ConnectionProvider newConnectionProvider(Properties properties, Map connectionProviderInjectionData) throws HibernateException {ConnectionProvider connections;String providerClass = properties.getProperty(Environment.CONNECTION_PROVIDER);if ( providerClass!=null ) {try {log.info("Initializing connection provider: " + providerClass);connections = (ConnectionProvider) ReflectHelper.classForName(providerClass).newInstance();}catch (Exception e) {log.fatal("Could not instantiate connection provider", e);throw new HibernateException("Could not instantiate connection provider: " + providerClass);}}else if ( properties.getProperty(Environment.DATASOURCE)!=null ) {connections = new DatasourceConnectionProvider();}else if ( properties.getProperty(Environment.C3P0_MAX_SIZE)!=null ) {connections = new C3P0ConnectionProvider();}else if (properties.getProperty(Environment.PROXOOL_XML)!=null ||properties.getProperty(Environment.PROXOOL_PROPERTIES)!=null ||properties.getProperty(Environment.PROXOOL_EXISTING_POOL)!=null) {connections = new ProxoolConnectionProvider();}else if ( properties.getProperty(Environment.URL)!=null ) {connections = new DriverManagerConnectionProvider();}else {connections = new UserSuppliedConnectionProvider();}if ( connectionProviderInjectionData != null && connectionProviderInjectionData.size() != 0 ) {//inject the datatry {BeanInfo info = Introspector.getBeanInfo( connections.getClass() );PropertyDescriptor[] descritors = info.getPropertyDescriptors();int size = descritors.length;for (int index = 0 ; index < size ; index++) {String propertyName = descritors[index].getName();if ( connectionProviderInjectionData.containsKey( propertyName ) ) {Method method = descritors[index].getWriteMethod();method.invoke( connections, new Object[] { connectionProviderInjectionData.get( propertyName ) } );}}}catch (IntrospectionException e) {throw new HibernateException("Unable to inject objects into the conenction provider", e);}catch (IllegalAccessException e) {throw new HibernateException("Unable to inject objects into the conenction provider", e);}catch (InvocationTargetException e) {throw new HibernateException("Unable to inject objects into the conenction provider", e);}}connections.configure(properties);return connections;}// cannot be instantiatedprivate ConnectionProviderFactory() { throw new UnsupportedOperationException(); }/** * Transform JDBC connection properties. * * Passed in the form <tt>hibernate.connection.*</tt> to the * format accepted by <tt>DriverManager</tt> by triming the leading "<tt>hibernate.connection</tt>". */public static Properties getConnectionProperties(Properties properties) {Iterator iter = properties.keySet().iterator();Properties result = new Properties();while ( iter.hasNext() ) {String prop = (String) iter.next();if ( prop.indexOf(Environment.CONNECTION_PREFIX) > -1 && !SPECIAL_PROPERTIES.contains(prop) ) {result.setProperty(prop.substring( Environment.CONNECTION_PREFIX.length()+1 ),properties.getProperty(prop));}}String userName = properties.getProperty(Environment.USER);if (userName!=null) result.setProperty( "user", userName );return result;}private static final Set SPECIAL_PROPERTIES;static {SPECIAL_PROPERTIES = new HashSet();SPECIAL_PROPERTIES.add(Environment.DATASOURCE);SPECIAL_PROPERTIES.add(Environment.URL);SPECIAL_PROPERTIES.add(Environment.CONNECTION_PROVIDER);SPECIAL_PROPERTIES.add(Environment.POOL_SIZE);SPECIAL_PROPERTIES.add(Environment.ISOLATION);SPECIAL_PROPERTIES.add(Environment.DRIVER);SPECIAL_PROPERTIES.add(Environment.USER);}}