/*
* $Header: /home/cvs/jakarta-slide/src/stores/org/apache/slide/store/txfile/XMLResourceDescriptor.java,v 1.15 2004/07/28 09:33:56 ib Exp $
* $Revision: 1.15 $
* $Date: 2004/07/28 09:33:56 $
*
* ====================================================================
*
* Copyright 1999-2004 The Apache Software Foundation
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
package org.apache.slide.store.txfile;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.apache.commons.transaction.file.FileResourceManager;
import org.apache.commons.transaction.file.ResourceManagerException;
import org.apache.commons.transaction.util.LoggerFacade;
import org.apache.slide.common.ServiceAccessException;
import org.apache.slide.common.Uri;
import org.apache.slide.structure.ObjectAlreadyExistsException;
import org.apache.slide.structure.ObjectNotFoundException;
import org.jdom.JDOMException;
/**
* XML descriptor as a resource in a {@link FileResourceManager}.
*
* @see FileResourceManager
* @see TxXMLFileDescriptorsStore
*/
public class XMLResourceDescriptor extends AbstractXMLResourceDescriptor {
protected static final String PATH_EXTENSION = ".def.xml";
protected final FileResourceManager rm;
protected final TxXMLFileDescriptorsStore store;
protected final String loadPath;
protected LoggerFacade logger;
/**
* Creates an XML descriptor resource.
*
* @param uri uri of the resource
* @param store store to use for error reporting
* @param rm resource manager to load / store this descriptor from / to
* @param txId identifier for the transaction in which the descriptor is to be managed
* @param characterEncoding charcter enconding used to store this descriptor in XML
* @throws ServiceAccessException if anything goes wrong at system level
*/
public XMLResourceDescriptor(
Uri uri,
TxXMLFileDescriptorsStore store,
FileResourceManager rm,
Object txId,
String characterEncoding)
throws ServiceAccessException {
super(uri, txId, characterEncoding);
logger = rm.getLogger().createLogger(XMLResourceDescriptor.class.getName());
this.rm = rm;
this.store = store;
this.loadPath = uri.toString() + PATH_EXTENSION;
}
/**
* Stores this descriptor to the resource manager.
*
* @throws ServiceAccessException if anything goes wrong at system level
* @throws ObjectNotFoundException if the descriptor has not been created before
*/
public void save() throws ServiceAccessException, ObjectNotFoundException {
if (txId == null) {
store.throwInternalError("Not inside tx");
}
logger.logFine("Tx " + txId + " saves data for " + loadPath);
OutputStream os = null;
try {
os = rm.writeResource(txId, loadPath);
save(os);
registeredForSaving = false;
} catch (ResourceManagerException e) {
if (e.getStatus() == ResourceManagerException.ERR_NO_SUCH_RESOURCE) {
throw new ObjectNotFoundException(uri);
} else {
store.throwInternalError(e, uri);
}
} catch (IOException e) {
store.throwInternalError(e);
} finally {
try {
if (os != null) {
os.close();
}
} catch (IOException e) {
}
}
}
/**
* Creates this descriptor in the resource manager.
*
* @throws ServiceAccessException if anything goes wrong at system level
* @throws ObjectAlreadyExistsException if the descriptor already exists
*/
public void create() throws ServiceAccessException, ObjectAlreadyExistsException {
logger.logFiner("Tx " + txId + " creates " + loadPath);
if (txId == null) {
store.throwInternalError("Not inside tx");
}
try {
rm.createResource(txId, loadPath, false);
init();
} catch (ResourceManagerException e) {
if (e.getStatus() == ResourceManagerException.ERR_RESOURCE_EXISTS) {
throw new ObjectAlreadyExistsException(uri.toString());
} else {
store.throwInternalError(e, uri);
}
}
}
/**
* Deletes this descriptor from the resource manager.
*
* @throws ServiceAccessException if anything goes wrong at system level
* @throws ObjectNotFoundException if the descriptor does not exist
*/
public void delete() throws ServiceAccessException, ObjectNotFoundException {
logger.logFiner("Tx " + txId + " deletes " + loadPath);
if (txId == null) {
store.throwInternalError("Not inside tx");
}
try {
rm.deleteResource(txId, loadPath, false);
object = null;
registeredForSaving = false; // do not save what is no longer there
} catch (ResourceManagerException e) {
if (e.getStatus() == ResourceManagerException.ERR_NO_SUCH_RESOURCE) {
throw new ObjectNotFoundException(uri.toString());
} else {
store.throwInternalError(e, uri);
}
}
}
/**
* Loads this descriptor from the resource manager.
*
* @throws ServiceAccessException if anything goes wrong at system level
* @throws ObjectNotFoundException if the descriptor does not exist
*/
public void load() throws ServiceAccessException, ObjectNotFoundException {
logger.logFiner("Tx " + txId + " loads data for " + loadPath);
InputStream is = null;
try {
if (txId != null) {
if (rm.resourceExists(txId, loadPath)) {
is = rm.readResource(txId, loadPath);
load(is);
} else {
init();
}
} else {
logger.logFinest("Faking read access from outside tx for " + loadPath);
if (rm.resourceExists(loadPath)) {
is = rm.readResource(loadPath);
load(is);
} else {
init();
}
}
} catch (JDOMException je) {
store.throwInternalError(je, uri);
} catch (IOException ioe) {
store.throwInternalError(ioe, uri);
} catch (ResourceManagerException e) {
if (e.getStatus() == ResourceManagerException.ERR_NO_SUCH_RESOURCE) {
throw new ObjectNotFoundException(uri);
} else {
store.throwInternalError(e, uri);
}
} finally {
try {
if (is != null) {
is.close();
}
} catch (IOException e) {
}
}
}
}