org.hibernate.jdbc.BorrowedConnectionProxy Maven / Gradle / Ivy
/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2008, Red Hat Middleware LLC or third-party contributors as
* indicated by the @author tags or express copyright attribution
* statements applied by the authors. All third-party contributions are
* distributed under license by Red Hat Middleware LLC.
*
* This copyrighted material is made available to anyone wishing to use, modify,
* copy, or redistribute it subject to the terms and conditions of the GNU
* Lesser General Public License, as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this distribution; if not, write to:
* Free Software Foundation, Inc.
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301 USA
*
*/
package org.hibernate.jdbc;
import org.hibernate.HibernateException;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.lang.reflect.InvocationTargetException;
import java.sql.Connection;
/**
* A proxy for borrowed connections which funnels all requests back
* into the ConnectionManager from which it was borrowed to be properly
* handled (in terms of connection release modes).
*
* Note: the term borrowed here refers to connection references obtained
* via {@link org.hibernate.Session#connection()} for application usage.
*
* @author Steve Ebersole
*/
public class BorrowedConnectionProxy implements InvocationHandler {
private static final Class[] PROXY_INTERFACES = new Class[] { Connection.class, ConnectionWrapper.class };
private final ConnectionManager connectionManager;
private boolean useable = true;
public BorrowedConnectionProxy(ConnectionManager connectionManager) {
this.connectionManager = connectionManager;
}
/**
* {@inheritDoc}
*/
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
if ( "close".equals( method.getName() ) ) {
connectionManager.releaseBorrowedConnection();
return null;
}
// should probably no-op commit/rollback here, at least in JTA scenarios
if ( !useable ) {
throw new HibernateException( "connnection proxy not usable after transaction completion" );
}
if ( "getWrappedConnection".equals( method.getName() ) ) {
return connectionManager.getConnection();
}
try {
return method.invoke( connectionManager.getConnection(), args );
}
catch( InvocationTargetException e ) {
throw e.getTargetException();
}
}
/**
* Generates a Connection proxy wrapping the connection managed by the passed
* connection manager.
*
* @param connectionManager The connection manager to wrap with the
* connection proxy.
* @return The generated proxy.
*/
public static Connection generateProxy(ConnectionManager connectionManager) {
BorrowedConnectionProxy handler = new BorrowedConnectionProxy( connectionManager );
return ( Connection ) Proxy.newProxyInstance(
getProxyClassLoader(),
PROXY_INTERFACES,
handler
);
}
/**
* Marks a borrowed connection as no longer usable.
*
* @param connection The connection (proxy) to be marked.
*/
public static void renderUnuseable(Connection connection) {
if ( connection != null && Proxy.isProxyClass( connection.getClass() ) ) {
InvocationHandler handler = Proxy.getInvocationHandler( connection );
if ( BorrowedConnectionProxy.class.isAssignableFrom( handler.getClass() ) ) {
( ( BorrowedConnectionProxy ) handler ).useable = false;
}
}
}
/**
* Convience method for unwrapping a connection proxy and getting a
* handle to an underlying connection.
*
* @param connection The connection (proxy) to be unwrapped.
* @return The unwrapped connection.
*/
public static Connection getWrappedConnection(Connection connection) {
if ( connection != null && connection instanceof ConnectionWrapper ) {
return ( ( ConnectionWrapper ) connection ).getWrappedConnection();
}
else {
return connection;
}
}
/**
* Determines the appropriate class loader to which the generated proxy
* should be scoped.
*
* @return The class loader appropriate for proxy construction.
*/
public static ClassLoader getProxyClassLoader() {
return ConnectionWrapper.class.getClassLoader();
}
}