/*
* Hibernate, Relational Persistence for Idiomatic Java
*
* Copyright (c) 2009 by Red Hat Inc and/or its affiliates or by
* third-party contributors as indicated by either @author tags or express
* copyright attribution statements applied by the authors. All
* third-party contributions are distributed under license by Red Hat Inc.
*
* 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.engine.jdbc;
import java.io.Serializable;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.sql.Blob;
import org.hibernate.HibernateException;
/**
* Manages aspects of proxying {@link Blob Blobs} to add serializability.
*
* @author Gavin King
* @author Steve Ebersole
* @author Gail Badner
*/
public class SerializableBlobProxy implements InvocationHandler, Serializable {
private static final Class[] PROXY_INTERFACES = new Class[] { Blob.class, WrappedBlob.class, Serializable.class };
private transient final Blob blob;
/**
* Builds a serializable {@link Blob} wrapper around the given {@link Blob}.
*
* @param blob The {@link Blob} to be wrapped.
* @see
*/
private SerializableBlobProxy(Blob blob) {
this.blob = blob;
}
public Blob getWrappedBlob() {
if ( blob == null ) {
throw new IllegalStateException( "Blobs may not be accessed after serialization" );
}
else {
return blob;
}
}
/**
* {@inheritDoc}
*/
public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
if ( "getWrappedBlob".equals( method.getName() ) ) {
return getWrappedBlob();
}
try {
return method.invoke( getWrappedBlob(), args );
}
catch ( AbstractMethodError e ) {
throw new HibernateException( "The JDBC driver does not implement the method: " + method, e );
}
catch ( InvocationTargetException e ) {
throw e.getTargetException();
}
}
/**
* Generates a SerializableBlob proxy wrapping the provided Blob object.
*
* @param blob The Blob to wrap.
*
* @return The generated proxy.
*/
public static Blob generateProxy(Blob blob) {
return ( Blob ) Proxy.newProxyInstance(
getProxyClassLoader(),
PROXY_INTERFACES,
new SerializableBlobProxy( blob )
);
}
/**
* 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() {
ClassLoader cl = Thread.currentThread().getContextClassLoader();
if ( cl == null ) {
cl = WrappedBlob.class.getClassLoader();
}
return cl;
}
}